Vaccines for preventing influenza in the elderly

Evidence base for yearly respiratory virus vaccines: Current status and proposed improved strategies

Annual vaccination is widely recommended for influenza and SARS-CoV-2. In this essay, we analyse and question the prevailing policymaking approach to these respiratory virus vaccines, especially in the United States. Every year, licensed influenza vaccines are reformulated to include specific strains expected to dominate in the season ahead. Updated vaccines are rapidly manufactured and approved without further regulatory requirement of clinical data. Novel vaccines (i.e. new products) typically undergo clinical trials, though generally powered for clinically unimportant outcomes (e.g. lab-confirmed infections, regardless of symptomatology or antibody levels). Eventually, the current and future efficacy of influenza and COVID-19 vaccines against hospitalization or death carries considerable uncertainty. The emergence of highly transmissible SARS-CoV-2 variants and waning vaccine-induced immunity led to plummeting vaccine effectiveness, at least against symptomatic infection, and booster doses have since been widely recommended. No further randomized trials were performed for clinically important outcomes for licensed updated boosters. In both cases, annual vaccine effectiveness estimates are generated by observational research, but observational studies are particularly susceptible to confounding and bias. Well-conducted experimental studies, particularly randomized trials, are necessary to address persistent uncertainties about influenza and COVID-19 vaccines. We propose a new research framework which would render results relevant to the current or future respiratory viral seasons. We demonstrate that experimental studies are feasible by adopting a more pragmatic approach and provide strategies on how to do so. When it comes to implementing policies that seriously impact people's lives, require substantial public resources and/or rely on widespread public acceptance, high evidence standards are desirable.

[Schätzung der Wirksamkeit der Grippeimpfung anhand von Sekundärdaten: Eine Kohortenstudie und Propensity-Score-Matching-Analyse von Leistungsdaten aus Baden-Württemberg]

Ziel war es die Wirksamkeit der Influenza-Impfung (VE) für die Grippesaison 2014/2015 auf Grundlage von Routinedaten aus Krankenkassendatensatz zu schätzen und zu replizieren. Zusätzlich sollten methodische Aspekte untersucht werden. Es wurden Abrechnungsdaten von 2,64 Millionen Versicherten der AOK Baden-Württemberg mit dortigem Wohnsitz ab 15 Jahren analysiert. Basierend auf Abrechnungsdaten für die Influenza-Impfung 2014, wurden die Teilnehmer als ungeimpft oder geimpft klassifiziert. Kovariablen, die den Zusammenhang zwischen Impfung und Influenzainfektion beeinträchtigen könnten, wurden berücksichtigt. Hierzu gehörten Alter, Geschlecht, Wohnort sowie Kovariablen, die auf den Gesundheitszustand und die Inanspruchnahme von Gesundheitsdienstleistungen hinweisen. Der primäre Endpunkt war ein Krankenhausaufenthalt wegen Influenza während der Grippesaison 2015. Zu den sekundären Endpunkten gehörten unter anderem Krankenhausaufenthalte wegen Lungenentzündung und die Gesamtmortalität. Um eine vergleichbare Gruppe von geimpften und ungeimpften Teilnehmern zu ermitteln, wurde ein Propensity-Score-Matching (PSM) durchgeführt. Es wurde eine Bias-Analyse durchgeführt, bei der die VE vor und nach der Grippesaison geschätzt wurde, also zu Zeitpunkten, in denen angenommen wurde, dass die Influenza nicht in der Bevölkerung zirkulierte und die Impfung nicht wirken konnte. Insgesamt konnten 839.706 Teilnehmer 1:1 gematcht werden. Die geschätzte VE (basierend auf Influenza bedingten Krankenhausaufenthalten) betrug 27% [95%Konfidenzintervall (KI): 17%; 36%], was der Schätzung des RKI für dieselbe Saison (27% [95%KI: -1%; 47%]) entspricht. Die Bias-Analyse zeigte, dass das Ergebnis teilweise durch residuale Konfundierung erklärt werden kann, was zu einer potenziellen Überschätzung des zugrunde liegenden Effekts führt. Die Ergebnisse der sekundären Endpunkte zeigten ähnliche Ergebnisse, obwohl sie wahrscheinlich in höherem Maße durch residuale Konfundierung bedingt sind. Zusammenfassend zeigt sich, dass (1) sekundäre Daten der deutschen Krankenkassen verwendet werden können, um plausible VE-Schätzungen abzuleiten, und dass (2) das PSM eine nützliche und transparente Methode zur Ableitung dieser Schätzungen ist. Darüber hinaus ist (3) residuale Konfundierung ein relevantes Problem in Beobachtungsstudien zu VE und (4) Bias-Analysen vor- und nach der Grippesaison sind eine wesentliche Ergänzung für die Interpretation der Ergebnisse.

Influenza Infection and Acute Myocardial Infarction

BACKGROUND

Acute respiratory infections can trigger acute myocardial infarction. We aimed to quantify the association between laboratory-confirmed influenza infection and acute myocardial infarction, particularly in patients with and without known coronary artery disease.

METHODS

This observational, registry-based, self-controlled case series study evaluated the association between laboratory-confirmed influenza infection and occurrence of acute myocardial infarction. Laboratory records on respiratory virus polymerase chain reaction (PCR) testing from 16 laboratories across the Netherlands were linked to national mortality, hospitalization, medication, and administrative registries. Influenza infection was defined as a positive PCR test result. Acute myocardial infarction was defined as a registered diagnostic code for either acute myocardial infarction hospitalization or death. Using a self-controlled case series method, we then compared the incidence of acute myocardial infarction during the risk period (days 1 to 7 after influenza infection) versus the control period (1 year before and 51 weeks after the risk period).

RESULTS

Between 2008 and 2019, we identified 158,777 PCR tests for influenza in the study population; 26,221 were positive for influenza, constituting 23,405 unique influenza illness episodes. A total of 406 episodes were identified with acute myocardial infarction occurring within 1 year before and 1 year after confirmed influenza infection and were included in analysis. Twenty-five cases of acute myocardial infarction occurred during the risk period versus 394 during the control period. The adjusted relative incidence of acute myocardial infarction during the risk period compared with the control period was 6.16 (95% confidence interval [CI], 4.11 to 9.24). The relative incidence of acute myocardial infarction in individuals without prior hospitalization for coronary artery disease was 16.60 (95% CI, 10.45 to 26.37) compared with 1.43 (95% CI, 0.53 to 3.84) for those with prior admission for coronary artery disease.

CONCLUSIONS

Influenza infection was associated with an increased risk of acute myocardial infarction, especially in individuals without a prior hospitalization for coronary artery disease. (Funded by the Dutch Research Council [NWO].).

How to protect long-term care facilities from pandemic-like events? - A systematic review on the effectiveness of non-pharmacological measures to prevent viral respiratory infections

BACKGROUND

The SARS-CoV-2 pandemic underscored the need for pandemic preparedness, with respiratory-transmitted viruses considered as a substantial risk. In pandemics, long-term care facilities (LTCFs) are a high-risk setting with severe outbreaks and burden of disease. Non-pharmacological interventions (NPIs) constitute the primary defence mechanism when pharmacological interventions are not available. However, evidence on the effectiveness of NPIs implemented in LTCFs remains unclear.

METHODS

We conducted a systematic review assessing the effectiveness of NPIs implemented in LTCFs to protect residents and staff from viral respiratory pathogens with pandemic potential. We searched Medline, Embase, CINAHL, and two COVID-19 registries in 09/2022. Screening and data extraction was conducted independently by two experienced researchers. We included randomized controlled trials and non-randomized observational studies of intervention effects. Quality appraisal was conducted using ROBINS-I and RoB2. Primary outcomes encompassed number of outbreaks, infections, hospitalizations, and deaths. We synthesized findings narratively, focusing on the direction of effect. Certainty of evidence (CoE) was assessed using GRADE.

RESULTS

We analysed 13 observational studies and three (cluster) randomized controlled trials. All studies were conducted in high-income countries, all but three focused on SARS-CoV-2 with the rest focusing on influenza or upper-respiratory tract infections. The evidence indicates that a combination of different measures and hand hygiene interventions can be effective in protecting residents and staff from infection-related outcomes (moderate CoE). Self-confinement of staff with residents, compartmentalization of staff in the LTCF, and the routine testing of residents and/or staff in LTCFs, among others, may be effective (low CoE). Other measures, such as restricting shared spaces, serving meals in room, cohorting infected and non-infected residents may be effective (very low CoE). An evidence gap map highlights the lack of evidence on important interventions, encompassing visiting restrictions, pre-entry testing, and air filtration systems.

CONCLUSIONS

Although CoE of interventions was low or very low for most outcomes, the implementation of NPIs identified as potentially effective in this review often constitutes the sole viable option, particularly prior to the availability of vaccinations. Our evidence-gap map underscores the imperative for further research on several interventions. These gaps need to be addressed to prepare LTCFs for future pandemics.

TRIAL REGISTRATION

CRD42022344149.

Public health and economic benefits of seasonal influenza vaccination in risk groups in France, Italy, Spain and the UK: state of play and perspectives

BACKGROUND

Seasonal influenza epidemics have a substantial public health and economic burden, which can be alleviated through vaccination. The World Health Organization (WHO) recommends a 75% vaccination coverage rate (VCR) in: older adults (aged ≥ 65 years), individuals with chronic conditions, pregnant women, children aged 6-24 months and healthcare workers. However, no European country achieves this target in all risk groups. In this study, potential public health and economic benefits achieved by reaching 75% influenza VCR was estimated in risk groups across four European countries: France, Italy, Spain, and the UK.

METHODS

A static epidemiological model was used to estimate the averted public health and economic burden of increasing the 2021/2022 season VCR to 75%, using the efficacy data of standard-dose quadrivalent influenza vaccine. For each country and risk group, the most recent data on population size, VCR, pre-pandemic influenza epidemiology, direct medical costs and absenteeism were identified through a systematic literature review, supplemented by manual searching. Outcomes were: averted influenza cases, general practitioner (GP) visits, hospitalisations, case fatalities, number of days of work lost, direct medical costs and absenteeism-related costs.

RESULTS

As of the 2021/2022 season, the UK achieved the highest weighted VCR across risk groups (65%), followed by Spain (47%), France (44%) and Italy (44%). Based on modelling, the 2021/2022 VCR prevented an estimated 1.9 million influenza cases, avoiding 375,200 GP visits, 73,200 hospitalisations and 38,400 deaths. To achieve the WHO 75% VCR target, an additional 24 million at-risk individuals would need to be vaccinated, most of which being older adults and patients with chronic conditions. It was estimated that this could avoid a further 918,200 influenza cases, 332,000 GP visits, 16,300 hospitalisations and 6,300 deaths across the four countries, with older adults accounting for 52% of hospitalisations and 80% of deaths. An additional €84 million in direct medical costs and €79 million in absenteeism costs would be saved in total, with most economic benefits delivered in France.

CONCLUSIONS

Older adults represent most vaccine-preventable influenza cases and deaths, followed by individuals with chronic conditions. Health authorities should prioritise vaccinating these populations for maximum public health and economic benefits.

Influenza vaccination for elderly, vulnerable and high-risk subjects: a narrative review and expert opinion

Influenza is associated with a substantial health burden, especially in high-risk subjects such as older adults, frail individuals and those with underlying chronic diseases. In this review, we summarized clinical findings regarding the impact of influenza in vulnerable populations, highlighted the benefits of influenza vaccination in preventing severe illness and complications and reviewed the main evidence on the efficacy, effectiveness and safety of the vaccines that are best suited to older adults among those available in Italy. The adverse outcomes associated with influenza infection in elderly and frail subjects and those with underlying chronic diseases are well documented in the literature, as are the benefits of vaccination (mostly in older adults and in patients with cardiovascular diseases, diabetes and chronic lung disease). High-dose and adjuvanted inactivated influenza vaccines were specifically developed to provide enhanced immune responses in older adults, who generally have low responses mainly due to immunosenescence, comorbidities and frailty. These vaccines have been evaluated in clinical studies and systematic reviews by international immunization advisory boards, including the European Centre for Disease Prevention and Control. The high-dose vaccine is the only licensed influenza vaccine to have demonstrated greater efficacy versus a standard-dose vaccine in preventing laboratory-confirmed influenza in a randomized controlled trial. Despite global recommendations, the vaccination coverage in high-risk populations is still suboptimal. All healthcare professionals (including specialists) have an important role in increasing vaccination rates.

The importance of falsification endpoints in observational studies of vaccination to prevent severe disease: A critique of a harm-benefit analysis of BNT162b2 vaccination of 5- to 11-year-olds

We explore one systematic review and meta-analysis of both observational and randomized studies examining COVID-19 vaccines in 5- to 11-year-olds, which reported substantial benefits associated with vaccinating this age group. We discuss the limitations of the individual studies that were used to estimate vaccination benefits. The review included five observational studies that evaluated vaccine effectiveness (VE) against COVID-19 severe disease or hospitalization. All five studies failed to adequately assess differences in underlying health between vaccination groups. In terms of vaccination harms, looking only at the randomized studies, a significantly higher odds of adverse events was identified among the vaccinated compared with the unvaccinated. Observational studies are at risk of overestimating the effectiveness of vaccines against severe disease if healthy vaccinee bias is present. Falsification endpoints can provide valuable information about underlying healthy vaccinee bias. Studies that have not adequately ruled out bias due to better health among the vaccinated or more vaccinated should be viewed as unreliable for estimating the VE of COVID-19 vaccination against severe disease and mortality. Existing systematic reviews that include observational studies of the COVID-19 vaccine in children may have overstated or falsely inferred vaccine benefits due to unidentified or undisclosed healthy vaccinee bias.

Reduced mortality, complications, and economic burden among medicare beneficiaries receiving influenza antivirals

INTRODUCTION

Antiviral therapy may be underutilized in patients at high risk for increased clinical and economic burden (e.g. older adults). We aimed to examine the benefits associated with antiviral treatment of seasonal influenza among treated and untreated Medicare beneficiaries.

METHODS

This retrospective study of Medicare Claims Research Identifiable Files identified patients ≥66 years old with an influenza diagnosis in outpatient setting between October 2016-March 2019 (flu seasons 2016-2018). Index date defined as date of first claim with influenza diagnosis; baseline as the 12 months pre-index. Treated patients received antivirals ≤2 days from index. Untreated patients had no antivirals ≤6 months post-index. Treated/untreated patients were 1:1 propensity score matched. Outcomes (death, all-cause and respiratory-related healthcare resource utilization [HCRU] and costs) were assessed until death or up to 6 months post-index. Descriptive statistics were reported; Kaplan-Meier estimation was used for survival over time.

RESULTS

Among 116,901 matched patient pairs, all-cause mortality within 6 months from index diagnosis was 1.6% among treated versus 4.3% among untreated patients. Rates (treated versus untreated) of all-cause inpatient hospitalizations during follow-up were 13.9% versus 22.7% and respiratory-related hospitalizations were 4.2% versus 9.0%. Mean (SD) total all-cause and respiratory-related costs were $9,830 ($18,616.0) and $900 ($4016.4) among the treated, respectively, versus $13,207 ($24,405.1) and $2,024 ($7,623.7) among untreated, respectively. All differences were statistically significant (p < 0.001).

CONCLUSIONS

Lack of antiviral treatment is associated with increased mortality, HCRU, and economic burden in older Medicare beneficiaries with seasonal influenza. Future research should investigate whether the choice of antivirals affects influenza burden.

Predictors of second COVID-19 booster dose or new COVID-19 vaccine hesitancy among nurses: A cross-sectional study

AIMS AND OBJECTIVES

To assess the levels of second COVID-19 booster dose/new COVID-19 vaccine hesitancy among nurses and explore the potential predictors of vaccine hesitancy.

BACKGROUND

COVID-19 full vaccination seems to be highly effective against highly contagious variants of SARS-CoV-2. Healthcare workers are at high-risk group since they have experienced high levels of COVID-19-associated morbidity and mortality.

DESIGN

An on-line cross-sectional study was carried out in Greece in May 2022, using a self-administered questionnaire.

METHODS

The study population included nurses in healthcare services who were fully vaccinated against COVID-19 at the time of study. We considered socio-demographic characteristics, COVID-19-related variables, and attitudes toward COVID-19 vaccination and pandemic as potential predictors of vaccine hesitancy. We applied the STROBE checklist in our study.

RESULTS

Among 795 nurses, 30.9% were hesitant toward a second booster dose or a new COVID-19 vaccine. Independent predictors of hesitancy included lower educational level, absence of a chronic condition, good/very good self-perceived physical health, lack of flu vaccination during 2021, front-line nurses that provided healthcare to COVID-19 patients, nurses that had not been diagnosed with COVID-19 and nurses that had at least one relative/friend that has died from COVID-19. Moreover, increased compliance with hygiene measures, increased fear of a second booster dose/new COVID-19 vaccine and decreased trust in COVID-19 vaccination were associated with increased hesitancy.

CONCLUSIONS

Our study shows that a significant percentage of nurses are hesitant toward a second booster dose/new COVID-19 vaccine. This initial hesitancy could be a barrier to efforts to control the COVID-19 pandemic.

RELEVANCE TO CLINICAL PRACTICE

Nurses' role during the COVID-19 pandemic is essential since they are the front-line healthcare workers empowering the public with their passion and empathy. There is a need to communicate COVID-19 vaccine science in a way that is accessible to nurses in order to decrease COVID-19 vaccine hesitancy.

PATIENT OR PUBLIC CONTRIBUTION

No patient or public contribution.

Factors associated with poor outcomes in patients with severe acute respiratory infections in Bahrain

Background

Severe acute respiratory tract infection (SARI) is a major global health threat. This study aimed to examine risk factors associated with poor outcomes in patients with SARI.

Methods

All patients who met World Health Organization's (WHO) SARI case definition and were admitted to Salmaniya Medical Complex from January 2018 to December 2021 were included. Epidemiological and virological data were obtained and analyzed.

Results

Of 1159 patients with SARI included, 731 (63.1%) patients were below 50 years, and 357 (30.8%) tested positive for viral pathogens. The most prevalent virus was Flu-A (n = 134, 37.5%), SARS-CoV2 (n = 118, 33%), RSV (n = 51, 14.3%), Flu B (n = 49,13.7%), other viruses (n = 3, 0.8%), and combined infection (n = 2, 0.6%). Six hundred fifty-eight (56.8%) patients had comorbidities, mainly diabetes (n = 284, 43%) and heart disease (n = 217, 33%). 183 (16%) patients were admitted to ICU, 110 (9%) needed mechanical ventilation, and 80 (7%) patients died.The odds of ICU admission were higher for patients with hematological (OR 5.9, 95% CI 3.1-11.1) and lung diseases (OR 2.7, 95% CI 1.6-4.6). The odds of mechanical ventilation were higher among patients with lung disease (OR 3.1, 95% 1.7-5.5). The mortality odds were higher among patients above 50 (OR 2.4, 95% CI 1.4-4.1) and chronic kidney disease (OR 2.5, 95% CI 1.1-5.2).

Conclusions

Being 50 years or above or having kidney, lung, or heart diseases was associated with worse SARI outcomes. Efforts and actions in developing better strategies to vaccinate individuals at high risk and early diagnosis and treatment should help in reducing the burden of SARI.

Physical interventions to interrupt or reduce the spread of respiratory viruses

BACKGROUND

Viral epidemics or pandemics of acute respiratory infections (ARIs) pose a global threat. Examples are influenza (H1N1) caused by the H1N1pdm09 virus in 2009, severe acute respiratory syndrome (SARS) in 2003, and coronavirus disease 2019 (COVID-19) caused by SARS-CoV-2 in 2019. Antiviral drugs and vaccines may be insufficient to prevent their spread. This is an update of a Cochrane Review last published in 2020. We include results from studies from the current COVID-19 pandemic.

OBJECTIVES

To assess the effectiveness of physical interventions to interrupt or reduce the spread of acute respiratory viruses.

SEARCH METHODS

We searched CENTRAL, PubMed, Embase, CINAHL, and two trials registers in October 2022, with backwards and forwards citation analysis on the new studies.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) and cluster-RCTs investigating physical interventions (screening at entry ports, isolation, quarantine, physical distancing, personal protection, hand hygiene, face masks, glasses, and gargling) to prevent respiratory virus transmission.  DATA COLLECTION AND ANALYSIS: We used standard Cochrane methodological procedures.

MAIN RESULTS

We included 11 new RCTs and cluster-RCTs (610,872 participants) in this update, bringing the total number of RCTs to 78. Six of the new trials were conducted during the COVID-19 pandemic; two from Mexico, and one each from Denmark, Bangladesh, England, and Norway. We identified four ongoing studies, of which one is completed, but unreported, evaluating masks concurrent with the COVID-19 pandemic. Many studies were conducted during non-epidemic influenza periods. Several were conducted during the 2009 H1N1 influenza pandemic, and others in epidemic influenza seasons up to 2016. Therefore, many studies were conducted in the context of lower respiratory viral circulation and transmission compared to COVID-19. The included studies were conducted in heterogeneous settings, ranging from suburban schools to hospital wards in high-income countries; crowded inner city settings in low-income countries; and an immigrant neighbourhood in a high-income country. Adherence with interventions was low in many studies. The risk of bias for the RCTs and cluster-RCTs was mostly high or unclear. Medical/surgical masks compared to no masks We included 12 trials (10 cluster-RCTs) comparing medical/surgical masks versus no masks to prevent the spread of viral respiratory illness (two trials with healthcare workers and 10 in the community). Wearing masks in the community probably makes little or no difference to the outcome of influenza-like illness (ILI)/COVID-19 like illness compared to not wearing masks (risk ratio (RR) 0.95, 95% confidence interval (CI) 0.84 to 1.09; 9 trials, 276,917 participants; moderate-certainty evidence. Wearing masks in the community probably makes little or no difference to the outcome of laboratory-confirmed influenza/SARS-CoV-2 compared to not wearing masks (RR 1.01, 95% CI 0.72 to 1.42; 6 trials, 13,919 participants; moderate-certainty evidence). Harms were rarely measured and poorly reported (very low-certainty evidence). N95/P2 respirators compared to medical/surgical masks We pooled trials comparing N95/P2 respirators with medical/surgical masks (four in healthcare settings and one in a household setting). We are very uncertain on the effects of N95/P2 respirators compared with medical/surgical masks on the outcome of clinical respiratory illness (RR 0.70, 95% CI 0.45 to 1.10; 3 trials, 7779 participants; very low-certainty evidence). N95/P2 respirators compared with medical/surgical masks may be effective for ILI (RR 0.82, 95% CI 0.66 to 1.03; 5 trials, 8407 participants; low-certainty evidence). Evidence is limited by imprecision and heterogeneity for these subjective outcomes. The use of a N95/P2 respirators compared to medical/surgical masks probably makes little or no difference for the objective and more precise outcome of laboratory-confirmed influenza infection (RR 1.10, 95% CI 0.90 to 1.34; 5 trials, 8407 participants; moderate-certainty evidence). Restricting pooling to healthcare workers made no difference to the overall findings. Harms were poorly measured and reported, but discomfort wearing medical/surgical masks or N95/P2 respirators was mentioned in several studies (very low-certainty evidence).  One previously reported ongoing RCT has now been published and observed that medical/surgical masks were non-inferior to N95 respirators in a large study of 1009 healthcare workers in four countries providing direct care to COVID-19 patients.  Hand hygiene compared to control Nineteen trials compared hand hygiene interventions with controls with sufficient data to include in meta-analyses. Settings included schools, childcare centres and homes. Comparing hand hygiene interventions with controls (i.e. no intervention), there was a 14% relative reduction in the number of people with ARIs in the hand hygiene group (RR 0.86, 95% CI 0.81 to 0.90; 9 trials, 52,105 participants; moderate-certainty evidence), suggesting a probable benefit. In absolute terms this benefit would result in a reduction from 380 events per 1000 people to 327 per 1000 people (95% CI 308 to 342). When considering the more strictly defined outcomes of ILI and laboratory-confirmed influenza, the estimates of effect for ILI (RR 0.94, 95% CI 0.81 to 1.09; 11 trials, 34,503 participants; low-certainty evidence), and laboratory-confirmed influenza (RR 0.91, 95% CI 0.63 to 1.30; 8 trials, 8332 participants; low-certainty evidence), suggest the intervention made little or no difference. We pooled 19 trials (71, 210 participants) for the composite outcome of ARI or ILI or influenza, with each study only contributing once and the most comprehensive outcome reported. Pooled data showed that hand hygiene may be beneficial with an 11% relative reduction of respiratory illness (RR 0.89, 95% CI 0.83 to 0.94; low-certainty evidence), but with high heterogeneity. In absolute terms this benefit would result in a reduction from 200 events per 1000 people to 178 per 1000 people (95% CI 166 to 188). Few trials measured and reported harms (very low-certainty evidence). We found no RCTs on gowns and gloves, face shields, or screening at entry ports.

AUTHORS' CONCLUSIONS

The high risk of bias in the trials, variation in outcome measurement, and relatively low adherence with the interventions during the studies hampers drawing firm conclusions. There were additional RCTs during the pandemic related to physical interventions but a relative paucity given the importance of the question of masking and its relative effectiveness and the concomitant measures of mask adherence which would be highly relevant to the measurement of effectiveness, especially in the elderly and in young children. There is uncertainty about the effects of face masks. The low to moderate certainty of evidence means our confidence in the effect estimate is limited, and that the true effect may be different from the observed estimate of the effect. The pooled results of RCTs did not show a clear reduction in respiratory viral infection with the use of medical/surgical masks. There were no clear differences between the use of medical/surgical masks compared with N95/P2 respirators in healthcare workers when used in routine care to reduce respiratory viral infection. Hand hygiene is likely to modestly reduce the burden of respiratory illness, and although this effect was also present when ILI and laboratory-confirmed influenza were analysed separately, it was not found to be a significant difference for the latter two outcomes. Harms associated with physical interventions were under-investigated. There is a need for large, well-designed RCTs addressing the effectiveness of many of these interventions in multiple settings and populations, as well as the impact of adherence on effectiveness, especially in those most at risk of ARIs.

Rethinking next-generation vaccines for coronaviruses, influenzaviruses, and other respiratory viruses

Viruses that replicate in the human respiratory mucosa without infecting systemically, including influenza A, SARS-CoV-2, endemic coronaviruses, RSV, and many other "common cold" viruses, cause significant mortality and morbidity and are important public health concerns. Because these viruses generally do not elicit complete and durable protective immunity by themselves, they have not to date been effectively controlled by licensed or experimental vaccines. In this review, we examine challenges that have impeded development of effective mucosal respiratory vaccines, emphasizing that all of these viruses replicate extremely rapidly in the surface epithelium and are quickly transmitted to other hosts, within a narrow window of time before adaptive immune responses are fully marshaled. We discuss possible approaches to developing next-generation vaccines against these viruses, in consideration of several variables such as vaccine antigen configuration, dose and adjuventation, route and timing of vaccination, vaccine boosting, adjunctive therapies, and options for public health vaccination polices.

The effectiveness of influenza vaccine among elderly Chinese: A regression discontinuity design based on Yinzhou regional health information platform

In China, a free influenza vaccination policy is being implemented among individuals aged 70 years and over in Zhejiang province during the COVID-19 pandemic. The objective was to assess the effectiveness of influenza vaccine in reducing hospitalization and mortality in the elderly. We used data from the Regional Health Information Platform in Yinzhou located in Zhejiang province and applied a regression discontinuity design to estimate the intention-to-treat effect on admission and mortality rates by month of age in the population who was near the age of 70 years threshold. At age 70 years, the influenza vaccination rate increased by 29.1% (95% CI, 28.2% to 29.9%) compared to those under 70 in the study population. When turning age 70 years, the potential effectiveness of receiving influenza vaccine was 8.2% (95% CI, -36.8% to 51.3%) for total hospitalization and the evaluation of vaccine effectiveness was 13.1% (95% CI, -34.2 to 61.8) for the all-cause mortality. An increase in the influenza vaccination rate was associated with a weak decline in most outcomes, but no significance was found for all outcomes. Influenza vaccination had a limited effect on hospital admission and mortality for the free influenza vaccination program that can be related to the low vaccination rate among the Chinese elderly. Supplementation strategies and future studies may be needed to expand immunization coverage and validate this finding, and further provide a reference for other cities to promote the free influenza vaccination policy in China, especially under circumstances of the COVID-19 pandemic.

Effectiveness of influenza vaccination on in-hospital death in older adults with respiratory diseases

Influenza vaccination is associated with lower risk of hospitalization outcomes among older adults with respiratory diseases, but there is limited evidence by disease subtypes and patients' characteristics. This study included patients aged ≥60 years hospitalized for respiratory diseases from the Beijing Urban Employee Basic Medical Insurance database during 6 influenza seasons. Vaccination status was assessed by linking with the Beijing Elderly Influenza Vaccination database. Multi-variable logistic regression was performed to calculate effect estimates. After adjusting for measured and unmeasured confounders, influenza vaccination was associated with a lower risk of in-hospital death among older adults hospitalized for respiratory diseases (odds ratio [95% confidence interval], 0.70 [0.62-0.80]). The protective association was observed among patients with chronic obstructive pulmonary disease (0.67 [0.47-0.98]) as well as those with pneumonia or influenza (0.77 [0.64-0.93]). The protective association was stronger in younger patients (0.59 [0.43-0.81] for <75 and 0.72 [0.63-0.83] for ≥75) and those with fewer comorbidities (0.49 [0.16-1.62] for 0, 0.65 [0.50-0.86] for 1-2, and 0.72 [0.63-0.83] for ≥3 comorbidities). Influenza vaccination was associated with lower risk of in-hospital death among older patients hospitalized for respiratory diseases, with stronger associations in patients with younger age and fewer comorbidities.

Focus group study on perceptions and information needs regarding vaccines targeting the older population: a cross-country comparison in four European countries

The increasing life expectancy leads to more older adults suffering from infectious diseases. Vaccines are available against diverse infections such as influenza, pneumococcal disease, herpes zoster and tetanus. However, vaccine acceptance is crucial for optimal preventive effect. The objective of the study is to perform a cross-country analysis of the perceptions and decision-making behaviour of older adults regarding vaccinations and their information needs. Focus groups with older adults were conducted in four countries: France, Hungary, Italy and the Netherlands. Data were analysed using thematic analysis. Demographic characteristics of participants were gathered with a questionnaire. Influenza and tetanus vaccines were commonly known, as was the disease influenza. On the contrary, the awareness of the vaccines against pneumococcal disease and herpes zoster were low. Participants also expressed a need for more information on vaccines, such as possible side effects, contra-indications and duration of protection, emphasizing that information is a condition for decision-making on vaccination. General practitioners were found to be the most important in information provision on vaccines. Perceptions on vaccines, such as effectiveness, side effects and safety, as well as perceptions on infectious diseases, such as severity, susceptibility and experiencing an infectious disease, played a role in the decision-making of older adults on vaccines. More awareness of the information needs among older adults with regard to vaccines should be raised among general practitioners and other healthcare providers. This requires appropriate knowledge about the vaccines among healthcare providers as well as communication skills to meet the information needs of older adults.

Ocular effects caused by viral infections and corresponding vaccines: An overview of varicella zoster virus, measles virus, influenza viruses, hepatitis B virus, and SARS-CoV-2

Many viral infections can affect vision and the visual system. Vaccination to prevent diseases is commonplace today, acting by stimulating an immune response without developing the pathology. It involves the production of persisting antibodies against the pathogen and the activation of T cells. Certain diseases have already been eradicated by rigorous vaccination campaigns, while others are hoped to be eliminated soon. Vaccines currently available on the market are largely safe, even if they can rarely cause some adverse effects, such as ocular complications. Analyzing existing literature, we aimed to compare the pathological effects on the eye due to the most common viral infections [in particular varicella zoster virus (VZV), measles virus, influenza viruses, hepatitis B virus, and SARS-CoV-2] with the possible ocular adverse effects of their relative vaccines, in order to establish a risk-benefit relationship from an ophthalmological point of view.

Repeated influenza vaccination induces similar immune protection as first-time vaccination but with differing immune responses

BACKGROUND

Recent seasonal epidemics of influenza have been caused by human influenza A viruses of the H1N1 and H3N2 subtypes and influenza B viruses. Annual vaccination is recommended to prevent infection; however, how annual influenza vaccination influences vaccine effectiveness is largely unknown.

METHODS

To investigate the impact of repeated vaccination on immune and protective effect, we performed a prospective seroepidemiologic study. Participants with or without prior vaccination (2018-2019) were enrolled during the 2019-2020 influenza season. Inactivated quadrivalent influenza vaccine (IIV4) was administered through the intramuscular route, and venous blood samples were collected regularly to test hemagglutination inhibition (HAI) titers.

RESULTS

The geometric mean titers and proportion with titers ≥40 against the influenza vaccine components peaked at 30 days post-vaccination. At Day 30, the geometric mean titer and proportion with titers ≥40 in participants who had been previously vaccinated were higher for H3N2 but similar for both B lineages (Victoria and Yamagata) as compared with participants vaccinated for the first time. As for H1N1, the geometric mean titer was lower in repeated vaccinated participants, but the proportion with titers ≥40 was consistent in both groups.

CONCLUSIONS

Repeated vaccination provides similar or enhanced protection as compared with single vaccination in first-time vaccinees.

Association of functional competencies with vaccination among older adults: a JAGES cross-sectional study

It is unknown whether higher functions in sublevels of competence other than instrumental activities of daily living (IADL) are associated with vaccinations. This study examined whether higher functions, including intellectual activity (IA) and social role (SR), were associated with vaccinations among 26,177 older adults. Older adults with incapable activities in IA and SR had increased risks for non-receipt of influenza vaccinations (IA: for one incapable task/activity: incident rate ratio (IRR) = 1.05, 95% confidence interval (CI) = 1.02-1.09; SR: for two incapable tasks: IRR = 1.12, 95% CI = 1.08-1.16). Those with incapable activities in IADL and IA had increased risks for non-receipt of pneumococcal vaccination (IADL: for two incapable tasks: IRR = 1.13, 95% CI = 1.05-1.23; IA: for two incapable tasks: IRR = 1.10, 95% CI = 1.08-1.12). Those with incapable activities in IADL, IA, and SR had increased risks for non-receipt of both of the two vaccinations (IADL: for two incapable tasks: IRR = 1.17, 95% CI = 1.03-1.33; IA: for two incapable tasks: IRR = 1.18, 95% CI = 1.11-1.25; SR: for two incapable tasks: IRR = 1.13, 95% CI = 1.07-1.20). Having a family physician mitigated associations for non-receipt, regardless of competency. Our results suggest-maintaining the higher functions are important for older adults to undergo recommended vaccinations as scheduled; also, having a family physician to promote vaccinations is beneficial even for older adults with limited functions.

Research progress on the antiviral activities of natural products and their derivatives: Structure–activity relationships

Viruses spread rapidly and are well-adapted to changing environmental events. They can infect the human body readily and trigger fatal diseases. A limited number of drugs are available for specific viral diseases, which can lead to non-efficacy against viral variants and drug resistance, so drugs with broad-spectrum antiviral activity are lacking. In recent years, a steady stream of new viral diseases has emerged, which has prompted development of new antiviral drugs. Natural products could be employed to develop new antiviral drugs because of their innovative structures and broad antiviral activities. This review summarizes the progress of natural products in antiviral research and their bright performance in drug resistance issues over the past 2 decades. Moreover, it fully discusses the effect of different structural types of natural products on antiviral activity in terms of structure–activity relationships. This review could provide a foundation for the development of antiviral drugs.

COVID-19: Clinical status of vaccine development to date

Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2)-induced COVID-19 is a complicated disease. Clinicians are continuously facing difficulties to treat infected patients using the principle of repurposing of drugs as no specific drugs are available to treat COVID-19. To minimize the severity and mortality, global vaccination is the only hope as a potential preventive measure. After a year-long global research and clinical struggle, 165 vaccine candidates have been developed and some are currently still in the pipeline. A total of 28 candidate vaccines have been approved for use and the remainder are in different phases of clinical trials. In this comprehensive report, the authors aim to demonstrate, classify and provide up-to-date clinical trial status of all the vaccines discovered to date and specifically focus on the approved candidates. Finally, the authors specifically focused on the vaccination of different types of medically distinct populations.

The role of cell-mediated immunity against influenza and its implications for vaccine evaluation

Influenza vaccines remain the most effective tools to prevent flu and its complications. Trivalent or quadrivalent inactivated influenza vaccines primarily elicit antibodies towards haemagglutinin and neuraminidase. These vaccines fail to induce high protective efficacy, in particular in older adults and immunocompromised individuals and require annual updates to keep up with evolving influenza strains (antigenic drift). Vaccine efficacy declines when there is a mismatch between its content and circulating strains. Current correlates of protection are merely based on serological parameters determined by haemagglutination inhibition or single radial haemolysis assays. However, there is ample evidence showing that these serological correlates of protection can both over- or underestimate the protective efficacy of influenza vaccines. Next-generation universal influenza vaccines that induce cross-reactive cellular immune responses (CD4+ and/or CD8+ T-cell responses) against conserved epitopes may overcome some of the shortcomings of the current inactivated vaccines by eliciting broader protection that lasts for several influenza seasons and potentially enhances pandemic preparedness. Assessment of cellular immune responses in clinical trials that evaluate the immunogenicity of these new generation vaccines is thus of utmost importance. Moreover, studies are needed to examine whether these cross-reactive cellular immune responses can be considered as new or complementary correlates of protection in the evaluation of traditional and next-generation influenza vaccines. An overview of the assays that can be applied to measure cell-mediated immune responses to influenza with their strengths and weaknesses is provided here.

Cost Effectiveness of Quadrivalent Versus Trivalent Inactivated Influenza Vaccines for the Portuguese Elderly Population

Background: quadrivalent inactivated vaccine (QIV) has replaced trivalent inactivated vaccine (TIV). In Portugal, TIV is free of charge for risk groups, including older adults (≥65 years old). In its turn, QIV—which provides broader protection as it includes an additional lineage B strain—was introduced in Portugal in October 2018; only since the 2019/20 influenza season has it been provided free of charge for risk groups. This study evaluates the cost effectiveness of switching from TIV to QIV, from the National Health Service perspective, in the Portuguese elderly mainland population. Methods: A decision tree model was developed to compare TIV and QIV, based on Portuguese hospitalization data for the 2015/16 influenza season. The primary health economic outcome under consideration was the incremental cost-effectiveness ratio (ICER). In addition, one-way sensitivity analysis and probabilistic sensitivity analysis were performed. Results: the high cost of QIV (approximately three times the cost of TIV) would lead to a total increment of EUR 5,283,047, and the resulting ICER would be EUR 26,403,007/QALY, above the usual willingness-to-pay threshold. Conclusions: from the National Health Service perspective, our findings reveal that QIV is not cost effective for the Portuguese elderly population due to the high cost. If the QIV costs were the same as the TIV, then QIV would be cost effective.

Quadrivalent Vaccines for the Immunization of Adults against Influenza: A Systematic Review of Randomized Controlled Trials

Vaccination is the most effective intervention to prevent influenza. Adults at risk of complications are among the targets of the vaccination campaigns and can be vaccinated with different types of quadrivalent influenza vaccines (QIVs). In the light of assessing the relative immunogenicity and efficacy of different QIVs, a systematic review was performed. Randomized controlled trials conducted in adults aged 18–64 years until 30 March 2021 were searched through three databases (Medline, Cochrane Library and Scopus). Twenty-four RCTs were eventually included. After data extraction, a network meta-analysis was not applicable due to the lack of common comparators. However, in the presence of at least two studies, single meta-analyses were performed to evaluate immunogenicity and efficacy; on the contrary, data from single studies were considered. Seroconversion rate for H1N1 was higher for standard QIVs, while for the remaining strains it was higher for low-dose adjuvanted QIVs. For seroprotection rate, the recombinant vaccine recorded the highest values for H3N2, while for the other strains, the cell-based QIVs achieved better results. In general, standard and cell-based QIVs showed an overall good immunogenicity profile. Nevertheless, as a relative comparative analysis was not possible, further research would be deserved.

Influenza vaccination coverage of professionals working in nursing homes in France and related determinants, 2018-2019 season: a cross-sectional survey

BACKGROUND

The burden of influenza morbidity and mortality in nursing homes (NH) is high. Vaccination of residents and professionals working in NH is the main prevention strategy. Despite recommendations, vaccination coverage among professionals is generally low.

METHODS

We performed a nationwide cross-sectional survey of NH using a single-stage stratified random sampling design to estimate influenza vaccination coverage in NH healthcare workers (HCW) and non-medical professionals in France during the 2018-2019 season, and to identify measures likely to increase it. For each NH, a questionnaire was completed with aggregated data by one member of the management team. A multivariate analysis was performed using a negative binomial regression.

RESULTS

Five-hundred and eighty nine NH filled in the study questionnaire (response rate: 49.5%). When considering all professionals (i.e., HCW and non-medical professionals), overall vaccination coverage was 30.6% (95%CI [28.2-33.0], range: 1.6-96.2). Overall influenza vaccination coverage in HCW was 31.9% [29.7-34.1]. It varied according to occupational category: 75.5% [69.3-81.7] for physicians, 42.9% [39.4-46.4] for nurses, 26.7% [24.5-29.0] for nursing assistants, and 34.0% [30.1-38.0] for other paramedical personnel. Vaccination coverage was higher i) in private nursing homes (RRa: 1.3, [1.1-1.5]), ii) in small nursing homes (0.9 [0.8-0.9]), iii) when vaccination was offered free of charge (1.4, [1.1-1.8]), iv) when vaccination promotion for professionals included individual (1.6 [1.1-2.1]) or collective (1.3 [1.1-1.5]) information sessions, videos or games (1.4 [1.2-1.6], v) when information on influenza vaccines was provided (1.2 [1.0-1.3], and finally, vi) when a vaccination point of contact-defined as an HCW who could provide reliable information on vaccination-was nominated within the nursing home (1.7 [1.3-2.2]).

CONCLUSIONS

Urgent and innovative actions are required to increase coverage in HCW. Vaccination programmes should include free on-site vaccination and education campaigns, and particularly target nursing assistants. The results of this nationwide study provide keys for improving influenza vaccination coverage in HCW. Programmes should ensure that information on influenza vaccines is provided by a vaccination point of contact in NH using attractive media. Combining the different prevention measures proposed could increase coverage in NH nationwide by over 50%.

Comparative efficacy and safety of vaccines to prevent seasonal influenza: A systematic review and network meta-analysis

BACKGROUND

Influenza is one of the most common respiratory viral infections worldwide. Numerous vaccines are used to prevent influenza. Their selection should be informed by the best available evidence. We aimed to estimate the comparative efficacy and safety of seasonal influenza vaccines in children, adults and the elderly.

METHODS

We conducted a systematic review and network meta-analysis (NMA). We searched the Cochrane Library Central Register of Controlled Trials, MEDLINE and EMBASE databases, and websites of regulatory agencies, through December 15th, 2020. We included placebo- or no vaccination-controlled, and head-to-head randomized clinical trials (RCTs). Pairs of reviewers independently screened the studies, abstracted the data, and appraised the risk of bias in accordance to the Cochrane Handbook for Systematic Reviews of Interventions. The primary outcome was laboratory-confirmed influenza. We also synthesized data for hospitalization, mortality, influenza-like illness (ILI), pneumonia or lower respiratory-tract disease, systemic and local adverse events (AEs). We estimated summary risk ratios (RR) using pairwise and NMA with random effects. This study is registered with PROSPERO, number CRD42018091895.

FINDINGS

We identified 13,439 citations. A total of 231 RCTs were included after screening: 11 studies did not provide useful data for the analysis; 220 RCTs [100,677 children (< 18 years) and 329,127 adults (18-60 years) and elderly (≥ 61 years)] were included in the NMA. In adults and the elderly, all vaccines, except the trivalent inactivated intradermal vaccine (3-IIV ID), were more effective than placebo in reducing the risk of laboratory-confirmed influenza, with a RR between 0.33 (95% credible interval [CrI] 0.21-0.55) for trivalent inactivated high-dose (3-IIV HD) and 0.56 (95% CrI 0.41-0.74) for trivalent live-attenuated vaccine (3-LAIV). In adults and the elderly, compared with trivalent inactivated vaccine (3-IIV), no significant differences were found for any, except 3-LAIV, which was less efficacious [RR 1.41 (95% CrI 1.04-1.88)]. In children, compared with placebo, RR ranged between 0.13 (95% CrI 0.03-0.51) for trivalent inactivated vaccine adjuvanted with MF59/AS03 and 0.55 (95% CrI 0.36-0.83) for trivalent inactivated vaccine. Compared with 3-IIV, 3-LAIV and trivalent inactivated adjuvanted with MF59/AS03 were more efficacious [RR 0.52 (95% CrI 0.32-0.82) and RR 0.23 (95% CrI 0.06-0.87)] in reducing laboratory-confirmed influenza. With regard to safety, higher systemic AEs rates after vaccination with 3-IIV, 3-IIV HD, 3-IIV ID, 3-IIV MF59/AS03-adj, quadrivalent inactivated (4-IIV), quadrivalent adjuvanted (4-IIV MF59/AS03-adj), quadrivalent recombinant (4-RIV), 3-LAIV or quadrivalent live attenuated (4-LAIV) vaccines were noted in adults and the elderly [RR 1.5 (95% CrI 1.18-1.89) to 1.15 (95% CrI 1.06-1.23)] compared with placebo. In children, the systemic AEs rate after vaccination was not significantly higher than placebo.

INTERPRETATION

All vaccines cumulatively achieved major reductions in the incidence of laboratory-confirmed influenza in children, adults, and the elderly. While the live-attenuated was more efficacious than the inactivated vaccine in children, many vaccine types can be used in adults and the elderly.

FUNDING

The directorate general of welfare, Lombardy region.

Cost-Effectiveness of Influenza Vaccination Strategies in Adults: Older Adults Aged ≥65 Years, Adults Aged 50–64 Years, and At-Risk Adults Aged 19–64 Years

The high disease burden of influenza in elderly and chronically ill adults may be due to the suboptimal effectiveness and mismatch of the conventional trivalent influenza vaccine (TIV). This study evaluated the cost-effectiveness of quadrivalent (QIV), adjuvanted trivalent (ATIV), and high-dose quadrivalent (HD-QIV) vaccines versus TIV used under the current Korean National Immunization Program (NIP) in older adults aged ≥65 years. We also evaluated the cost-effectiveness of programs for at-risk adults aged 19–64 and adults aged 50–64. A one-year static population model was used to compare the costs and outcomes of alternative vaccination programs in each targeted group. Influenza-related parameters were derived from the National Health Insurance System claims database; other inputs were extracted from the published literature. Incremental cost-effectiveness ratios (ICERs) were assessed from a societal perspective. In the base case analysis (older adults aged ≥65 years), HD-QIV was superior, with the lowest cost and highest utility. Compared with TIV, ATIV was cost-effective (ICER $34,314/quality-adjusted life-year [QALY]), and QIV was not cost-effective (ICER $46,486/QALY). The cost-effectiveness of HD-QIV was robust for all parameters except for vaccine cost. The introduction of the influenza NIP was cost-effective or even cost-saving for the remaining targeted gr3oups, regardless of TIV or QIV.

Seasonal influenza vaccine awareness and factors affecting vaccination in Turkish Society

Objective

Influenza vaccine reduces the burden of seasonal influenza and related complications. Potential vaccination barriers need to be identified to raise awareness and increase acceptance. We aimed to investigate the rates of seasonal influenza vaccination and the knowledge, opinions, and behaviours prevalent in Turkish society.

Methods

The study among seven regions in Turkey was conducted from October-November 2018 in 28 family health centres, using a cross-sectional, descriptive design. The knowledge, opinions, and behaviours of participants regarding the influenza vaccine were obtained by family physicians through face-to-face interviews with participants.

Results

A total of 3,492 people aged 10-97 years age range (median: 50 years) were included in the study. Over half of the participants (59.9%, n = 2093) were female. It was found that the percentage of participants who never received the influenza vaccine was 78.4%; only 13.4% were occasionally vaccinated, and 8.1% received regular annual vaccination. Influenza vaccination rates were higher in married people (p < 0.001), women (p = 0.005), patients with chronic lung and cardiovascular disease (p < 0.001), those over 65 years /nursing home residents (p < 0.001). Awareness of the vaccine's benefit was higher in the group at high risk of influenza (p < 0.001).

Conclusion

The rate of regular vaccination against influenza every year was insufficient, at 8.1%. Individuals' insensitivity, insufficient knowledge, and attitudes toward influenza vaccination is a serious health problem for Turkish society. Barriers to influenza vaccination can be reduced by good communication between family physicians and their patients.

Effectiveness of influenza vaccination in the elderly: a population-based case-crossover study

BACKGROUND

There is limited information regarding the effectiveness of influenza vaccines for older adults. Particularly, controlling for healthy senior bias is challenging in observational studies. We aimed to assess the efficacy of influenza vaccination in the elderly while addressing potential healthy senior bias and whether it was related to virus-vaccine strains matching.

METHOD

To control between-individual confounder, we used a case-crossover study design using Taiwan's National Health Insurance Research Dataset to analyse the association between influenza vaccination in older adults and the risk of hospitalisation for community-acquired pneumonia (CAP). Individuals were a 'case' in vaccinated years and a 'control' in unvaccinated years. The study periods were 2006/2007 and 2007/2008 seasons because virus-vaccine strains were matching in 2006/2007 season and unmatching in 2007/2008 season. Older adults were categorised into two groups: admitted for CAP during the pre-vaccination period (Admitted, n=311) and not hospital admitted for CAP (Non-admitted, n=572 432). The outcome was hospitalisation for CAP during the influenza period. Conditional logistic regression assessed influenza vaccine efficacy in reducing CAP.

RESULTS

Influenza vaccination had no protective effects in Admitted group. However, because of the tiny numbers in Admitted group, we could draw very limited conclusions. Receiving an influenza vaccine significantly prevented CAP in Non-admitted group only during the vaccine-circulating strain-matched year (OR, 0.72; 95% CI, 0.64 to 0.83). In addition, there was no protective effect against CAP hospitalisation among individuals with a Charlson Comorbidity Index score over 2.

CONCLUSION

Influenza vaccine efficacy was associated with vaccine-circulating strain-matched. When vaccine-circulating strains were all matching, receiving a shot reduced the probability of CAP hospitalisation by 28% in Non-admitted group. However, high comorbidity may reduce the vaccine efficacy. Therefore, it is necessary to educate older adults to receive annual influenza vaccination and in combination with non-pharmaceutical interventions to reduce the risk of CAP.

Crohn's and Colitis Canada's 2021 Impact of COVID-19 and Inflammatory Bowel Disease in Canada: Seniors With IBD

The risk of hospitalization and death from Coronavirus disease-19 (COVID-19) increases with age. The extreme elderly have been particularly vulnerable, with those above the age of 80 having a case-fatality rate as high as 15%. Aging of the immune system can lead to impaired inflammatory responses where eradication of an organism such as Severe Acute Respiratory Syndrome CoronaVirus 2 (SARS-CoV2) is inadequate but is exaggerated in such a way as to enhance pneumonia and acute respiratory distress syndrome. Frailty and comorbidity are both more common in the elderly, and these can enhance the morbidity and mortality from COVID-19. Studies from Northern California and Italy suggest that elderly persons with inflammatory bowel disease (IBD) were more likely to acquire SARS-CoV-2 infection than youths with IBD. While the specific impact of age-related comorbidity is less well established among people with IBD who acquire COVID-19, data from the Surveillance Epidemiology of Coronavirus Under Research Exclusion (SECURE-IBD) database reported that having two or more chronic illnesses was independently associated with developing severe COVID-19 among people with IBD. Despite having exaggerated auto-inflammatory responses, people with IBD do not appear to have an overall increased risk of developing severe COVID-19 than the general population. However, whether seniors with IBD do worse once they acquire COVID-19 compared with seniors without IBD is not known. The advent of telehealth care has posed an information technology challenge for many seniors with and without IBD. Most persons with IBD have expressed satisfaction with virtual IBD health care (phone or video-based visits). While the elderly may have less robust immune responses to vaccinations, learning from experiences with other vaccination programs, especially influenza, have shown that vaccinating seniors decreases both morbidity and mortality and, in turn, healthcare resources.

Influenza Neuraminidase Characteristics and Potential as a Vaccine Target

Neuraminidase of influenza A and B viruses plays a critical role in the virus life cycle and is an important target of the host immune system. Here, we highlight the current understanding of influenza neuraminidase structure, function, antigenicity, immunogenicity, and immune protective potential. Neuraminidase inhibiting antibodies have been recognized as correlates of protection against disease caused by natural or experimental influenza A virus infection in humans. In the past years, we have witnessed an increasing interest in the use of influenza neuraminidase to improve the protective potential of currently used influenza vaccines. A number of well-characterized influenza neuraminidase-specific monoclonal antibodies have been described recently, most of which can protect in experimental challenge models by inhibiting the neuraminidase activity or by Fc receptor-dependent mechanisms. The relative instability of the neuraminidase poses a challenge for protein-based antigen design. We critically review the different solutions that have been proposed to solve this problem, ranging from the inclusion of stabilizing heterologous tetramerizing zippers to the introduction of inter-protomer stabilizing mutations. Computationally engineered neuraminidase antigens have been generated that offer broad, within subtype protection in animal challenge models. We also provide an overview of modern vaccine technology platforms that are compatible with the induction of robust neuraminidase-specific immune responses. In the near future, we will likely see the implementation of influenza vaccines that confront the influenza virus with a double punch: targeting both the hemagglutinin and the neuraminidase.

Reasons for nonadherence to vaccination for influenza among older people in Brazil

This study aimed to estimate the prevalence of non-vaccination and the reasons for nonadherence to the influenza vaccine among older Brazilians according to sociodemographic characteristics. A cross-sectional study was conducted with data from older people (≥ 60 years of age; n = 23,815) who participated in the 2013 National Health Survey. Frequencies of non-vaccination and the main reasons for nonadherence were calculated with respective 95% confidence intervals. The prevalence of non-vaccination was 26.9% (approximately 7,106,730 older people). The reason rarely gets the flu was the most cited among the men (28.2%), the 60-to-69-year-old age group (29.6%), individuals with higher education (41.9%), and those with health insurance (32.3%). Fear of a reaction was the most cited reason in the northeastern region (25.4%), among women (29.3%), longer-lived individuals (≥70 years; 28.7%), and those who did not know how to read/write (26.7%). A total of 12.1% reported not believing in the vaccine's protection, and 5.5% did not know that it was necessary to take vaccine. The proportions of the main reasons for non-vaccination varied by sociodemographic characteristics. This study's findings highlight the need to increase older people's knowledge regarding influenza and influenza vaccines. Healthcare providers should be encouraged to counsel older people-especially those in subgroups with lower adherence, such as residents in the Northeast region, those aged 60-69 years, those who do not know how to read/write, those without a spouse/companion, and those without health insurance-regarding the different aspects of the vaccine and formally indicate it for groups at risk.

Safety of Influenza A H1N1pdm09 Vaccines: An Overview of Systematic Reviews

Background

In 2009, a new influenza A H1N1 virus emerged causing a global pandemic. A range of monovalent influenza A H1N1pdm09 vaccines with or without adjuvants were developed. After the mass vaccination campaigns safety concerns related to H1N1pdm09 vaccines were reported. More than a decade later, reported AEFIs are still under scrutiny. We performed a systematic review aiming to synthesize the evidence on the safety of the H1N1pdm09 vaccines on reported outcomes from existing systematic reviews.

Methods

Four electronic databases, PubMed, EMBASE, Epistimonikos and the Cochrane Database of Systematic Reviews were searched for articles on H1N1pdm09 vaccination published from 2009 to January 2021. Systematic reviews assessing short- or long-term adverse events after H1N1pdm09 vaccination were considered for inclusion. Data was extracted from all selected reviews. Outcomes were grouped and results from each included review were presented narratively and in tables.

Results

16 systematic reviews met the inclusion criteria. Reported outcomes were short-term events (3 reviews), fetal/pregnancy outcomes (8 reviews), Guillain-Barré syndrome (GBS) (4 reviews), narcolepsy (2 reviews) demyelinating diseases (1 review based on one study only) and inflammatory bowel disease (IBD) (1 review). Short-term serious adverse events were rare, 3 cases amongst 16725 subjects in 18 randomized controlled trials (0.018%). No deaths were reported. The risks of local events were generally higher for adjuvanted vaccines as compared to unadjuvanted vaccines. Maternal H1N1pdm09 vaccination in any trimester was not associated with an increase in preterm birth, small for gestational age, congenital malformations or fetal death. For GBS, results were conflicting. The main systematic review on narcolepsy found a 5-14-fold increased risk in children, and a 2-7- fold increased risk in adults after vaccination with Pandemrix. The attributable risk of narcolepsy one year after vaccination was 1 case per 18 400 vaccine doses in children/adolescents, and 1 case per 181 000 vaccine doses in adults.

Conclusion

Adjuvanted vaccines had more local but not serious adverse events compared to unadjuvanted vaccines. Vaccination with Pandemrix was strongly associated with narcolepsy, particularly in children. No increased risks of pregnancy outcomes were seen after pandemic vaccination. The findings on GBS were inconclusive.

Influenza Vaccines: Successes and Continuing Challenges

Influenza vaccines have been available for over 80 years. They have contributed to significant reductions in influenza morbidity and mortality. However, there have been limitations in their effectiveness, in part due to the continuous antigenic evolution of seasonal influenza viruses, but also due to the predominant use of embryonated chicken eggs for their production. The latter furthermore limits their worldwide production timelines and scale. Therefore today, alternative approaches for their design and production are increasingly pursued, with already licensed quadrivalent seasonal influenza vaccines produced in cell cultures, including based on a baculovirus expression system. Next-generation influenza vaccines aim at inducing broader and longer-lasting immune responses to overcome seasonal influenza virus antigenic drift and to timely address the emergence of a new pandemic influenza virus. Tailored approaches target mechanisms to improve vaccine-induced immune responses in individuals with a weakened immune system, in particular older adults.

Endoplasmic reticulum stress response and bile acid signatures associate with multi-strain seroresponsiveness during elderly influenza vaccination

The elderly are an important target for influenza vaccination, and the determination of factors that underlie immune responsiveness is clinically valuable. We evaluated the immune and metabolic profiles of 205 elderly Singaporeans administered with Vaxigrip. Despite high seroprotection rates, we observed heterogeneity in the response. We stratified the cohort into complete (CR) or incomplete responders (IR), where IR exhibited signs of accelerated T cell aging. We found a higher upregulation of genes associated with the B-cell endoplasmic-reticulum stress response in CR, where XBP-1 acts as a key upstream regulator. B-cells from IR were incapable of matching the level of XBP-1 upregulation observed in CR after inducing ER stress with tunicamycin in vitro. Metabolic signatures also distinguished CR and IR - as CR presented with a greater diversity of bile acids. Our findings suggest that the ER-stress pathway activation could improve influenza vaccination in the elderly.

The Impact of the COVID-19 Emergency on Life Activities and Delivery of Healthcare Services in the Elderly Population

Due to the prevailing pandemic of the coronavirus disease COVID-19, we are experiencing emotional and social isolation, which negatively affects mental and physical health, particularly among the elderly population. In this study, we performed a cross-sectional analysis based on computer-assisted telephone interviews of 500 Polish adults aged 60 years or older in order to determine the impact of the SARS-CoV-2 pandemic on the older population’s behavior, life activity, and delivery of healthcare services. According to our study, COVID-19 infection entailed a substantial change in older people’s behavior. Over 50%, nearly 80%, and more than 25% of the surveyed participants reduced their social, recreational, and professional activities, respectively. The most significant change in senior’s behavior due to the fear of COVID-19 infection was observed in patients (1) with cardiac and pulmonary problems, (2) being on multi-drug therapy, (3) vaccinated against influenza, and (4) with several mental difficulties including loneliness, social isolation, and depression. Furthermore, we demonstrated that 10% of participants canceled planned hospitalization due to the fear of COVID-19 infection. This was observed primarily in patients suffering from chronic heart and lung diseases, vaccinated against influenza, exhibiting the reluctance to carry out more complex daily activities, and with a higher level of anxiety, social loneliness, and malnutrition. Thus, these groups of seniors require more attention; hence, we propose telemedicine as a strategy directed to them that provides clinical healthcare and information regarding measurements, control, and protection against SARS-CoV-2 during the prevailing COVID-19 pandemic. We believe this strategy may improve treatment outcomes, reduce comorbidities-related complications and unnecessary hospitalizations.

Safety and Tolerability of the Adeno-Associated Virus Vector, AAV6.2FF, Expressing a Monoclonal Antibody in Murine and Ovine Animal Models

Adeno-associated virus (AAV) vector mediated expression of therapeutic monoclonal antibodies is an alternative strategy to traditional vaccination to generate immunity in immunosuppressed or immunosenescent individuals. In this study, we vectorized a human monoclonal antibody (31C2) directed against the spike protein of SARS-CoV-2 and determined the safety profile of this AAV vector in mice and sheep as a large animal model. In both studies, plasma biochemical parameters and hematology were comparable to untreated controls. Except for mild myositis at the site of injection, none of the major organs revealed any signs of toxicity. AAV-mediated human IgG expression increased steadily throughout the 28-day study in sheep, resulting in peak concentrations of 21.4–46.7 µg/ mL, demonstrating practical scale up from rodent to large animal models. This alternative approach to immunity is worth further exploration after this demonstration of safety, tolerability, and scalability in a large animal model.

Influenza Vaccine Effectiveness Against All-Cause Mortality Following Laboratory-Confirmed Influenza in Older Adults, 2010-2011 to 2015-2016 Seasons in Ontario, Canada

BACKGROUND

Older adults are at increased risk of mortality from influenza infections. We estimated influenza vaccine effectiveness (VE) against mortality following laboratory-confirmed influenza.

METHODS

Using a test-negative design study and linked laboratory and health administrative databases in Ontario, Canada, we estimated VE against all-cause mortality following laboratory-confirmed influenza for community-dwelling adults aged >65 years during the 2010-2011 to 2015-2016 influenza seasons.

RESULTS

Among 54 116 older adults tested for influenza across the 6 seasons, 6837 died within 30 days of specimen collection. Thirteen percent (925 individuals) tested positive for influenza, and 50.6% were considered vaccinated for that season. Only 23.2% of influenza test-positive cases had influenza recorded as their underlying cause of death. Before and after multivariable adjustment, we estimated VE against all-cause mortality following laboratory-confirmed influenza to be 20% (95% confidence interval [CI], 8%-30%) and 20% (95% CI, 7%-30%), respectively. This estimate increased to 34% after correcting for influenza vaccination exposure misclassification. We observed significant VE against deaths following influenza confirmation during 2014-2015 (VE = 26% [95% CI, 5%-42%]). We also observed significant VE against deaths following confirmation of influenza A/H1N1 and A/H3N2, and against deaths with COPD as the underlying cause.

CONCLUSIONS

These results support the importance of influenza vaccination in older adults, who account for most influenza-associated deaths annually.

Trends in influenza coverage rates in five consecutive immunisation seasons in the Local Health Unit of Ferrara (North Italy)

Seasonal influenza epidemics yearly affects 5-15% of the world's population, resulting in 3-5 million serious cases and up to 650,000 deaths. Elderly, pregnant women and individuals with underlying conditions are at increased risk of complications. According to the Italian National Immunisation Prevention Plan 2017-2019, these categories benefit from free vaccination but coverage rate in Italy are below desirable levels. The study considered the coverage rate in five consecutive influenza seasons (2010/2011-2014/2015) in Local Health Unit (LHU) of Ferrara (Italy). The amount of delivered vaccinations was not constant, with a decreasing trend. Coverage rose with increasing age, but the 75% target of over-65 years old individuals immunised was never achieved. In addition to age, coverage rates varied also according to District (the area of residence within the LHU). The District with the lowest vaccination coverage was the Western District. Higher levels of immunisation were observed in South-Eastern District in the pediatric age and in North-Central District in adult age group with a statistically significant difference. In the considered timespan, the percentage of immunisations delivered by the General Practitioners (GPs) increased. The trend in the LHU of Ferrara was similar to regional and national data, conditioned in the 2014/2015 season by the spreading of worrying news, although unfounded, on the safety of the vaccine. The GPs were essential in ensuring vaccine uptake, growing the percentage of delivered doses and achieving as much as possible effective elderly immunisation.

Effectiveness of a Multifaceted Informational-Based and Text Message Reminders on Pneumococcal and Influenza Vaccinations in Hospital Emergency Departments: A Cluster-Randomized Controlled Trial

Objectives. We aimed to evaluate the effectiveness of a multifaceted procedure in improving pneumococcal and influenza vaccinations 6 months after an emergency department (ED) visit among patients aged 65 years and older. Methods. We conducted a cluster-randomized, controlled, parallel-group, open-label implementation trial in 18 EDs in France and Monaco. Participants were recruited from November 2015 to September 2016. EDs were randomly assigned with a 1:1 ratio to provide either a multifaceted procedure that combined structured information about pneumococcal and influenza vaccines and three text message reminders sent to patients every two weeks (intervention arm) or nonstructured information only (control arm). The outcomes were self-reported pneumococcal vaccination and influenza vaccination rates within 6 months of enrollment. Results. A total of 9 EDs were randomized to the intervention arm (n = 780 patients) and 9 to the control arm (n = 695 patients). The median age for all enrolled patients was 74 years (25–75th percentiles, 69 to 82): 50.1% were male, 34.9% had at least one underlying condition, and 30.7% were at risk for invasive pneumococcal infection. In the intention-to-treat analysis, the multifaceted intervention did not alter the pneumococcal vaccination rate (6.4% versus 4.6%, absolute difference: 1.8; 95% CI: [−0.9 to 4.4]; p = 0.19), whereas it improved the influenza vaccination rate (52.1% versus 40.0%, absolute difference: 12.1; 95% CI: [2.4 to 21.8]; p = 0.01). At 12 months, mortality did not differ between the intervention (9.7%) and control (11.2%) arms (p = 0.35). Conclusions. A multifaceted intervention based on text message reminders provides an opportunity to increase anti-influenza vaccination among elderly patients visiting the ED. Efforts are warranted to provide better information on pneumococcal diseases and the benefits of pneumococcal vaccines, especially in the elderly.

Cellular senescence in lymphoid organs and immunosenescence

Immunosenescence is a multi-faceted phenomenon at the root of age-associated immune dysfunction. It can lead to an array of pathological conditions, including but not limited to a decreased capability to surveil and clear senescent cells (SnCs) and cancerous cells, an increased autoimmune responses leading to tissue damage, a reduced ability to tackle pathogens, and a decreased competence to illicit a robust response to vaccination. Cellular senescence is a phenomenon by which oncogene-activated, stressed or damaged cells undergo a stable cell cycle arrest. Failure to efficiently clear SnCs results in their accumulation in an organism as it ages. SnCs actively secrete a myriad of molecules, collectively called senescence-associated secretory phenotype (SASP), which are factors that cause dysfunction in the neighboring tissue. Though both cellular senescence and immunosenescence have been studied extensively and implicated in various pathologies, their relationship has not been greatly explored. In the wake of an ongoing pandemic (COVID-19) that disproportionately affects the elderly, immunosenescence as a function of age has become a topic of great importance. The goal of this review is to explore the role of cellular senescence in age-associated lymphoid organ dysfunction and immunosenescence, and provide a framework to explore therapies to rejuvenate the aged immune system.

Risk Factors Associated with 30-Day Mortality in Older Patients with Influenza

Background: Influenza is a common viral condition, but factors related to short-term mortality have not been fully studied in older adults. Our objective was to determine whether there is an association between geriatric factors and 30-day mortality. Methods: This was a retrospective cohort design. All patients aged 75 years and over, with a diagnosis of influenza confirmed by a positive RT-PCR, were included. The primary endpoint was death within the 30 days after diagnosis. Results: 114 patients were included; 14 (12.3%) patients died within 30 days. In multivariate analysis these patients were older (OR: 1.37 95% CI (1.05, 1.79), p = 0.021), and had a lower ADL score (OR: 0.36 95% CI (0, 17; 0.75), p = 0.006), and a higher SOFA score (OR: 2.30 95% CI (1.07, 4.94), p = 0.03). Oseltamivir treatment, initiated within the first 48 h, was independently associated with survival (OR: 0.04 95% CI (0.002, 0.78), p = 0.034). Conclusions: Identification of mortality risk factors makes it possible to consider specific secondary prevention measures such as the rapid introduction of antiviral treatment. Combined with primary prevention, these measures could help to limit the mortality associated with influenza in older patients.

Canadian Association of Gastroenterology Clinical Practice Guideline for Immunizations in Patients With Inflammatory Bowel Disease (IBD)-Part 2: Inactivated Vaccines

BACKGROUND AND AIMS

The effectiveness and safety of vaccinations can be altered by immunosuppressive therapies, and perhaps by inflammatory bowel disease (IBD) itself. These recommendations developed by the Canadian Association of Gastroenterology and endorsed by the American Gastroenterological Association, aim to provide guidance on immunizations in adult and pediatric patients with IBD. This publication focused on inactivated vaccines.

METHODS

Systematic reviews evaluating the efficacy, effectiveness, and safety of vaccines in patients with IBD, other immune-mediated inflammatory diseases, and the general population were performed. Critical outcomes included mortality, vaccine-preventable diseases, and serious adverse events. Immunogenicity was considered a surrogate outcome for vaccine efficacy. Certainty of evidence and strength of recommendations were rated according to the GRADE (Grading of Recommendation Assessment, Development, and Evaluation) approach. Key questions were developed through an iterative online platform, and voted on by a multidisciplinary group. Recommendations were formulated using the Evidence-to-Decision framework. Strong recommendation means that most patients should receive the recommended course of action, whereas a conditional recommendation means that different choices will be appropriate for different patients.

RESULTS

Consensus was reached on 15 of 20 questions. Recommendations address the following vaccines: Haemophilus influenzae type b, recombinant zoster, hepatitis B, influenza, pneumococcus, meningococcus, tetanus-diphtheria-pertussis, and human papillomavirus. Most of the recommendations for patients with IBD are congruent with the current Centers for Disease Control and Prevention and Canada's National Advisory Committee on Immunization recommendations for the general population, with the following exceptions. In patients with IBD, the panel suggested Haemophilus influenzae type b vaccine for patients older than 5 years of age, recombinant zoster vaccine for adults younger than 50 year of age, and hepatitis B vaccine for adults without a risk factor. Consensus was not reached, and recommendations were not made for 5 statements, due largely to lack of evidence, including double-dose hepatitis B vaccine, timing of influenza immunization in patients on biologics, pneumococcal and meningococcal vaccines in adult patients without risk factors, and human papillomavirus vaccine in patients aged 27-45 years.

CONCLUSIONS

Patients with IBD may be at increased risk of some vaccine-preventable diseases. Therefore, maintaining appropriate vaccination status in these patients is critical to optimize patient outcomes. In general, IBD is not a contraindication to the use of inactivated vaccines, but immunosuppressive therapy may reduce vaccine responses.

Healthcare workers' perceptions and experiences of communicating with people over 50 years of age about vaccination: a qualitative evidence synthesis

BACKGROUND

Infectious diseases are a major cause of illness and death among older adults. Vaccines can prevent infectious diseases, including against seasonal influenza, pneumococcal diseases, herpes zoster and COVID-19. However, the uptake of vaccination among older adults varies across settings and groups. Communication with healthcare workers can play an important role in older people's decisions to vaccinate. To support an informed decision about vaccination, healthcare workers should be able to identify the older person's knowledge gaps, needs and concerns. They should also be able to share and discuss information about the person's disease risk and disease severity; the vaccine's effectiveness and safety; and practical information about how the person can access vaccines. Therefore, healthcare workers need good communication skills and to actively keep up-to-date with the latest evidence. An understanding of their perceptions and experiences of this communication can help us train and support healthcare workers and design good communication strategies.

OBJECTIVES

To explore healthcare workers' perceptions and experiences of communicating with older adults about vaccination.

SEARCH METHODS

We searched MEDLINE, CINAHL and Scopus on 21 March 2020. We also searched Epistemonikos for related reviews, searched grey literature sources, and carried out reference checking and citation searching to identify additional studies. We searched for studies in any language.

SELECTION CRITERIA

We included qualitative studies and mixed-methods studies with an identifiable qualitative component. We included studies that explored the perceptions and experiences of healthcare workers and other health system staff towards communication with adults over the age of 50 years or their informal caregivers about vaccination.

DATA COLLECTION AND ANALYSIS

We extracted data using a data extraction form designed for this review. We assessed methodological limitations using a list of predefined criteria. We extracted and assessed data regarding study authors' motivations for carrying out their study. We used a thematic synthesis approach to analyse and synthesise the evidence. We used the GRADE-CERQual (Confidence in the Evidence from Reviews of Qualitative research) approach to assess our confidence in each finding. We examined each review finding to identify factors that may influence intervention implementation and we developed implications for practice.

MAIN RESULTS

We included 11 studies in our review. Most studies explored healthcare workers' views and experiences about vaccination of older adults more broadly but also mentioned communication issues specifically. All studies were from high-income countries. The studies focused on doctors, nurses, pharmacists and others working in hospitals, clinics, pharmacies and nursing homes. These healthcare workers discussed different types of vaccines, including influenza, pneumococcal and herpes zoster vaccines. The review was carried out before COVID-19 vaccines were available. We downgraded our confidence in several of the findings from high confidence to moderate, low or very low confidence. One reason for this was that some findings were based on only small amounts of data. Another reason was that the findings were based on studies from only a few countries, making us unsure about the relevance of these findings to other settings. Healthcare workers reported that older adults asked about vaccination to different extents, ranging from not asking about vaccines at all, to great demand for information (high confidence finding). When the topic of vaccination was discussed, healthcare workers described a lack of information, and presence of misinformation, fears and concerns about vaccines among older adults (moderate confidence). The ways in which healthcare workers discussed vaccines with older adults appeared to be linked to what they saw as the aim of vaccination communication. Healthcare workers differed among themselves in their perceptions of this aim and about their own roles and the roles of older adults in vaccine decisions. Some healthcare workers thought it was important to provide information but emphasised the right and responsibility of older adults to decide for themselves. Others used information to persuade and convince older adults to vaccinate in order to increase 'compliance' and 'improve' vaccination rates, and in some cases to gain financial benefits. Other healthcare workers tailored their approach to what they believed the older adult needed or wanted (moderate confidence). Healthcare workers believed that older adults' decisions could be influenced by several factors, including the nature of the healthcare worker-patient relationship, the healthcare worker's status, and the extent to which healthcare workers led by example (low confidence). Our review also identified factors that are likely to influence how communication between healthcare workers and older adults take place. These included issues tied to healthcare workers' views and experiences regarding the diseases in question and the vaccines; as well as their views and experiences of the organisational and practical implementation of vaccine services.

AUTHORS' CONCLUSIONS

There is little research focusing specifically on healthcare workers' perceptions and experiences of communication with older adults about vaccination. The studies we identified suggest that healthcare workers differed among themselves in their perceptions about the aim of this communication and about the role of older adults in vaccine decisions. Based on these findings and the other findings in our review, we have developed a set of questions or prompts that may help health system planners or programme managers when planning or implementing strategies for vaccination communication between healthcare workers and older adults.

A Comparative NLP-Based Study on the Current Trends and Future Directions in COVID-19 Research

COVID-19 is a global health crisis that has altered human life and still promises to create ripples of death and destruction in its wake. The sea of scientific literature published over a short time-span to understand and mitigate this global phenomenon necessitates concerted efforts to organize our findings and focus on the unexplored facets of the disease. In this work, we applied natural language processing (NLP) based approaches on scientific literature published on COVID-19 to infer significant keywords that have contributed to our social, economic, demographic, psychological, epidemiological, clinical, and medical understanding of this pandemic. We identify key terms appearing in COVID literature that vary in representation when compared to other virus-borne diseases such as MERS, Ebola, and Influenza. We also identify countries, topics, and research articles that demonstrate that the scientific community is still reacting to the short-term threats such as transmissibility, health risks, treatment plans, and public policies, underpinning the need for collective international efforts towards long-term immunization and drug-related challenges. Furthermore, our study highlights several long-term research directions that are urgently needed for COVID-19 such as: global collaboration to create international open-access data repositories, policymaking to curb future outbreaks, psychological repercussions of COVID-19, vaccine development for SARS-CoV-2 variants and their long-term efficacy studies, and mental health issues in both children and elderly.

Aging and Options to Halt Declining Immunity to Virus Infections

Immunosenescence is a process associated with aging that leads to dysregulation of cells of innate and adaptive immunity, which may become dysfunctional. Consequently, older adults show increased severity of viral and bacterial infections and impaired responses to vaccinations. A better understanding of the process of immunosenescence will aid the development of novel strategies to boost the immune system in older adults. In this review, we focus on major alterations of the immune system triggered by aging, and address the effect of chronic viral infections, effectiveness of vaccination of older adults and strategies to improve immune function in this vulnerable age group.

Cost-Effectiveness Analysis of Switching from Trivalent to Quadrivalent Seasonal Influenza Vaccine in Argentina

The burden of seasonal influenza disease in Argentina is considerable. The cost-effectiveness of trivalent (TIV) versus quadrivalent influenza vaccine (QIV) in Argentina was assessed. An age-stratified, static, decision-tree model compared the costs and benefits of vaccination for an average influenza season. Main outcomes included: numbers of influenza cases; general practitioner (GP) visits; complicated ambulatory cases; hospitalizations; deaths averted; and costs per quality-adjusted life years (QALYs) gained. Epidemiological data from Argentina for 2014–2019 were used to determine the proportion of A and B strain cases, and the frequency of mismatch between vaccine and circulating B strains. To manage uncertainty, one-way and probabilistic sensitivity analyses were performed. Switching from TIV to QIV would prevent 19,128 influenza cases, 16,164 GP visits, 2440 complicated ambulatory cases, 524 hospitalizations, and 82 deaths. Incremental cost–effectiveness ratios (ICERs) per QALY were 13,590 and 11,678 USD from the payer’s and societal perspectives, respectively. The greatest health benefits and direct medical cost savings would occur in ≥ 65-year-olds. One-way sensitivity analyses demonstrated the principal drivers of ICER to be vaccine acquisition costs, environmental B strain predominance, and B strain mismatch. Introducing QIV in Argentina would be beneficial and cost-effective relative to TIV, particularly in older adults.

Primary care physician volume and quality of care for older adults with dementia: a retrospective cohort study

BACKGROUND

Some jurisdictions restrict primary care physicians' daily patient volume to safeguard quality of care for complex patients. Our objective was to determine whether people with dementia receive lower-quality care if their primary care physician sees many patients daily.

METHODS

Population-based retrospective cohort study using health administrative data from 100,256 community-living adults with dementia aged 66 years or older, and the 8,368 primary care physicians who cared for them in Ontario, Canada. Multivariable Poisson GEE regression models tested whether physicians' daily patient volume was associated with the adjusted likelihood of people with dementia receiving vaccinations, prescriptions for cholinesterase inhibitors, benzodiazepines, and antipsychotics from their primary care physician.

RESULTS

People with dementia whose primary care physicians saw ≥ 30 patients daily were 32% (95% CI: 23% to 41%, p < 0.0001) and 25% (95% CI: 17% to 33%, p < 0.0001) more likely to be prescribed benzodiazepines and antipsychotic medications, respectively, than patients of primary care physicians who saw < 20 patients daily. Patients were 3% (95% CI: 0.4% to 6%, p = 0.02) less likely to receive influenza vaccination and 8% (95% CI: 4% to 13%, p = 0.0001) more likely to be prescribed cholinesterase inhibitors if their primary care physician saw ≥ 30 versus < 20 patients daily.

CONCLUSIONS

People with dementia were more likely to receive both potentially harmful and potentially beneficial medications, and slightly less likely to be vaccinated by high-volume primary care physicians.

SARS-CoV-2 B cell receptor signatures in at-risk populations

Many individuals possess B cells capable of recognizing epitopes on the spike glycoprotein of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). In this issue of the JCI, Paschold and Simnica et al. interrogated the frequency of SARS-CoV-2-specific B cell receptor rearrangements in healthy subjects based on age and cancer status. The authors found that while SARS-CoV-2-specific antibody signatures can be identified in the repertoires of young, healthy individuals, such sequences are less frequent in elderly subjects or patients with cancer. Overall, this study sheds light on B cell repertoire restrictions that might lead to an unfavorable clinical course of coronavirus disease 2019 infection in at-risk populations.