Duration of vaccine effectiveness against SARS-CoV-2 infection, hospitalisation, and death in residents and staff of long-term care facilities in England (VIVALDI): a prospective cohort study

Evaluating the Usefulness of Population-Wide COVID-19 Testing in the Omicron Era: Insights from a German Model

BACKGROUND

The Omicron variant of SARS-CoV-2, which has become dominant worldwide since late 2021, presents a unique challenge due to its high rate of asymptomatic transmission. This study evaluates the efficacy and value of population-wide testing, including self-testing, in the context of COVID-19, particularly under the Omicron variant, using data from Germany.

METHODS

A decision-analytical model and secondary data was used for assessing the impact of systematic screening and testing for COVID-19. Various scenarios were taken into consideration including seasonal patterns of COVID-19 transmission and the potential for annual waves. The model assessed the clinical benefits of testing against the backdrop of vaccine effectiveness, transmission rates, and the potential to prevent severe clinical events, including death, ICU admission, and long COVID syndrome.

RESULTS

The study found that the value of mass testing and self-testing for private use was highly contingent on the transmission rate and the scenario of COVID-19 waves (seasonal vs. continuous). For winter waves, a very high incidence rate was required to justify testing, while for continuous waves, testing could be valuable for those in contact with individuals in their last decade of life. The analysis highlighted the limitations of mass testing when community transmission rates were low and the potential value of testing in high-risk contacts or amidst new outbreaks.

DISCUSSION

The findings suggest that the resumption of testing during winter waves is unlikely to provide significant clinical benefits given the current understanding of Omicron's transmission and immunity waning. This study underscores the need for a nuanced approach to COVID-19 testing policies, considering both the epidemiological context and the practical implications of testing strategies.

Analysis of the impact of COVID-19 on Scotland's care-homes from March 2020 to October 2021: national linked data cohort analysis

BACKGROUND

The impact of the COVID-19 pandemic on long-term care residents remains of wide interest, but most analyses focus on the initial wave of infections.

OBJECTIVE

To examine change over time in: (i) The size, duration, classification and pattern of care-home outbreaks of COVID-19 and associated mortality and (ii) characteristics associated with an outbreak.

DESIGN

Retrospective observational cohort study using routinely-collected data.

SETTING

All adult care-homes in Scotland (1,092 homes, 41,299 places).

METHODS

Analysis was undertaken at care-home level, over three periods. Period (P)1 01/03/2020-31/08/2020; P2 01/09/2020-31/05/2021 and P3 01/06/2021-31/10/2021. Outcomes were the presence and characteristics of outbreaks and mortality within the care-home. Cluster analysis was used to compare the pattern of outbreaks. Logistic regression examined care-home characteristics associated with outbreaks.

RESULTS

In total 296 (27.1%) care-homes had one outbreak, 220 (20.1%) had two, 91 (8.3%) had three, and 68 (6.2%) had four or more. There were 1,313 outbreaks involving residents: 431 outbreaks in P1, 559 in P2 and 323 in P3. The COVID-19 mortality rate per 1,000 beds fell from 45.8 in P1, to 29.3 in P2, and 3.5 in P3. Larger care-homes were much more likely to have an outbreak, but associations between size and outbreaks were weaker in later periods.

CONCLUSIONS

COVID-19 mitigation measures appear to have been beneficial, although the impact on residents remained severe until early 2021. Care-home residents, staff, relatives and providers are critical groups for consideration and involvement in future pandemic planning.

COVID-19-related mortality and hospital admissions in the VIVALDI study cohort: October 2020 to March 2023

BACKGROUND

Long-term-care facilities (LTCFs) were heavily affected by COVID-19 early in the pandemic, but the impact of the virus has reduced over time with vaccination campaigns and build-up of immunity from prior infection.

OBJECTIVES

To evaluate the mortality and hospital admissions associated with SARS-CoV-2 in LTCFs in England over the course of the VIVALDI study, from October 2020 to March 2023.

METHODS

We included residents aged ≥65 years from participating LTCFs who had available follow-up time within the analysis period. We calculated incidence rates (IRs) of COVID-19-linked mortality and hospital admissions per calendar quarter, along with infection fatality ratios (IFRs, within 28 days) and infection hospitalization ratios (IHRs, within 14 days) following positive SARS-CoV-2 test.

RESULTS

A total of 26,286 residents were included, with at least one positive test for SARS-CoV-2 in 8513 (32.4%). The IR of COVID-19-related mortality peaked in the first quarter (Q1) of 2021 at 0.47 per 1000 person-days (1 kpd) (around a third of all deaths), in comparison with 0.10 per 1 kpd for Q1 2023 which had a similar IR of SARS-CoV-2 infections. There was a fall in observed IFR for SARS-CoV-2 infections from 24.9% to 6.7% between these periods, with a fall in IHR from 12.1% to 8.8%. The population had high overall IRs for mortality for each quarter evaluated, corresponding to annual mortality probability of 28.8-41.3%.

CONCLUSIONS

Standardized real-time monitoring of hospitalization and mortality following infection in LTCFs could inform policy on the need for non-pharmaceutical interventions to prevent transmission.

The Epidemiological Analysis of COVID-19 Outbreaks in Nursing Homes during the Period of Omicron Variant Predominance

BACKGROUND

The main purpose of this study was to evaluate the epidemic trend and risk factors associated with COVID-19 outbreaks in nursing homes during the period of Omicron variant predominance.

METHODS

The study analyzed the risk factors associated with SARS-CoV-2 infection and death among the 327 residents and 129 healthcare workers (HCWs) in three hospital-affiliated nursing homes through a multivariate Cox regression model.

RESULTS

The rates of receiving a COVID-19 booster dose were 70.3% for the residents and 93.0% for the healthcare workers (HCWs), respectively. A number of asymptomatic individuals, including 54 (16.5%) residents and 15 (11.6%) HCWs, were detected through mass screening surveillance tests. The COVID-19 infection rates during the outbreaks were 41.6% among residents and 48.1% among HCWs, respectively. The case fatality rate among residents was 10.3%. None of the HCWs were hospitalized or died. The multivariate Cox regression model showed that the risk of COVID-19 infection increased in males (HR 2.46; 95% CI 1.47-4.11; p = 0.001), Barthel index ≥ 61 (HR 1.93; 95% CI 1.18-3.17; p = 0.009), and dementia (HR 1.61; 95% CI 1.14-2.27; p = 0.007). The risk of COVID-19 death increased with pneumonia (HR 11.03; 95% CI 3.02-40.31; p < 0.001), hospitalization (HR 7.18; 95% CI 1.97-26.25; p = 0.003), and admission to an intensive care unit (HR 8.67; 95% CI 2.79-26.89; p < 0.001).

CONCLUSIONS

This study highlighted the high infection rates with a substantial proportion of asymptomatic infections for both residents and HCWs, as well as a high case fatality rate for the residents among nursing homes during the Omicron epidemic period. We suggest implementing mass screening through regular surveillance testing as an effective strategy for early detection of COVID-19 and for preventing transmission during an epidemic period. Pneumonia is the primary risk associated with COVID-19 death. Early detection and prompt treatment of pneumonia for vulnerable residents in nursing homes are crucial to protect them from potential mortality.

Protection from infection and reinfection due to the Omicron BA.1 variant in care homes

Introduction

Following the emergence of SARS-CoV-2 in 2020, care homes were disproportionately impacted by high mortality and morbidity of vulnerable elderly residents. Non-pharmaceutical interventions (NPIs) and improved infection control measures together with vaccination campaigns have since improved outcomes of infection. We studied the utility of past infection status, recent vaccination and anti-S antibody titres as possible correlates of protection against a newly emergent Omicron variant infection.

Methods

Prospective longitudinal surveillance of nine sentinel London care homes from April 2020 onwards found that all experienced COVID-19 outbreaks due to Omicron (BA.1) during December 2021 and January 2022, despite extensive prior SARS-CoV-2 exposure and high COVID-19 vaccination rates, including booster vaccines (>70% residents, >40% staff).

Results

Detailed investigation showed that 46% (133/288) of Omicron BA.1 infections were SARS-CoV-2 reinfections. Two and three COVID-19 vaccine doses were protective against Omicron infection within 2-9 weeks of vaccination, though protection waned from 10 weeks post-vaccination. Prior infection provided additional protection in vaccinated individuals, approximately halving the risk of SARS-CoV-2 infection.

Discussion

Anti-S antibody titre showed a dose-dependent protective effect but did not fully account for the protection provided by vaccination or past infection, indicating that other mechanisms of protection are also involved.

Effectiveness of successive booster vaccine doses against SARS-CoV-2 related mortality in residents of long-term care facilities in the VIVALDI study

BACKGROUND

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) caused severe disease in unvaccinated long-term care facility (LTCF) residents. Initial booster vaccination following primary vaccination is known to provide strong short-term protection, but data are limited on duration of protection and the protective effect of further booster vaccinations.

OBJECTIVE

To evaluate the effectiveness of third, fourth and fifth dose booster vaccination against SARS-CoV-2 related mortality amongst older residents of LTCFs.

DESIGN

Prospective cohort study.

SETTING

LTCFs for older people in England participating in the VIVALDI study.

METHODS

Residents aged >65 years at participating LTCFs were eligible for inclusion if they had at least one polymerase chain reaction or lateral flow device result within the analysis period 1 January 2022 to 31 December 2022. We excluded individuals who had not received at least two vaccine doses before the analysis period. Cox regression was used to estimate relative hazards of SARS-CoV-2 related mortality following 1-3 booster vaccinations compared with primary vaccination, stratified by previous SARS-CoV-2 infection and adjusting for age, sex and LTCF size (total beds).

RESULTS

A total of 13,407 residents were included. Our results indicate that third, fourth and fifth dose booster vaccination provide additional short-term protection against SARS-CoV-2 related mortality relative to primary vaccination, with consistent stabilisation beyond 112 days to 45-75% reduction in risk relative to primary vaccination.

CONCLUSIONS

Successive booster vaccination doses provide additional short-term protection against SARS-CoV-2 related mortality amongst older LTCF residents. However, we did not find evidence of a longer-term reduction in risk beyond that provided by initial booster vaccination.

Spatial dysregulation of T follicular helper cells impairs vaccine responses in aging

The magnitude and quality of the germinal center (GC) response decline with age, resulting in poor vaccine-induced immunity in older individuals. A functional GC requires the co-ordination of multiple cell types across time and space, in particular across its two functionally distinct compartments: the light and dark zones. In aged mice, there is CXCR4-mediated mislocalization of T follicular helper (TFH) cells to the dark zone and a compressed network of follicular dendritic cells (FDCs) in the light zone. Here we show that TFH cell localization is critical for the quality of the antibody response and for the expansion of the FDC network upon immunization. The smaller GC and compressed FDC network in aged mice were corrected by provision of TFH cells that colocalize with FDCs using CXCR5. This demonstrates that the age-dependent defects in the GC response are reversible and shows that TFH cells support stromal cell responses to vaccines.

Adverse outcomes of SARS-CoV-2 infection with delta and omicron variants in vaccinated versus unvaccinated US veterans: retrospective cohort study

OBJECTIVES

To determine the association between covid-19 vaccination types and doses with adverse outcomes of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection during the periods of delta (B.1.617.2) and omicron (B.1.1.529) variant predominance.

DESIGN

Retrospective cohort.

SETTING

US Veterans Affairs healthcare system.

PARTICIPANTS

Adults (≥18 years) who are affiliated to Veterans Affairs with a first documented SARS-CoV-2 infection during the periods of delta (1 July-30 November 2021) or omicron (1 January-30 June 2022) variant predominance. The combined cohorts had a mean age of 59.4 (standard deviation 16.3) and 87% were male.

INTERVENTIONS

Covid-19 vaccination with mRNA vaccines (BNT162b2 (Pfizer-BioNTech) and mRNA-1273 (Moderna)) and adenovirus vector vaccine (Ad26.COV2.S (Janssen/Johnson & Johnson)).

MAIN OUTCOME MEASURES

Stay in hospital, intensive care unit admission, use of ventilation, and mortality measured 30 days after a positive test result for SARS-CoV-2.

RESULTS

In the delta period, 95 336 patients had infections with 47.6% having at least one vaccine dose, compared with 184 653 patients in the omicron period, with 72.6% vaccinated. After adjustment for patient demographic and clinical characteristics, in the delta period, two doses of the mRNA vaccines were associated with lower odds of hospital admission (adjusted odds ratio 0.41 (95% confidence interval 0.39 to 0.43)), intensive care unit admission (0.33 (0.31 to 0.36)), ventilation (0.27 (0.24 to 0.30)), and death (0.21 (0.19 to 0.23)), compared with no vaccination. In the omicron period, receipt of two mRNA doses were associated with lower odds of hospital admission (0.60 (0.57 to 0.63)), intensive care unit admission (0.57 (0.53 to 0.62)), ventilation (0.59 (0.51 to 0.67)), and death (0.43 (0.39 to 0.48)). Additionally, a third mRNA dose was associated with lower odds of all outcomes compared with two doses: hospital admission (0.65 (0.63 to 0.69)), intensive care unit admission (0.65 (0.59 to 0.70)), ventilation (0.70 (0.61 to 0.80)), and death (0.51 (0.46 to 0.57)). The Ad26.COV2.S vaccination was associated with better outcomes relative to no vaccination, but higher odds of hospital stay and intensive care unit admission than with two mRNA doses. BNT162b2 was generally associated with worse outcomes than mRNA-1273 (adjusted odds ratios between 0.97 and 1.42).

CONCLUSIONS

In veterans with recent healthcare use and high occurrence of multimorbidity, vaccination was robustly associated with lower odds of 30 day morbidity and mortality compared with no vaccination among patients infected with covid-19. The vaccination type and number of doses had a significant association with outcomes.

COVID-19 outbreak trends in Canada, 2021

Background

In January 2021, the Public Health Agency of Canada launched an outbreak surveillance system, the Canadian COVID-19 Outbreak Surveillance System (CCOSS), with the goal of monitoring incidence and severity of coronavirus disease 2019 (COVID-19) outbreaks across various community settings and complementing case surveillance.

Methods

Seven provinces were included in this report; these provinces submitted weekly cumulative COVID-19 outbreak line lists to CCOSS in 2021. Data includes administrative variables (e.g. date outbreak declared, date outbreak declared over, outbreak identifier), 24 outbreak settings, and number of confirmed cases and outcomes (hospitalization, death). Descriptive analyses for COVID-19 outbreaks across Canada from January 3, 2021, to January 1, 2022, were performed examining trends over time, severity, and outbreak size.

Results

Incidence of outbreaks followed similar trends to case incidence. Outbreaks were most common in school and childcare settings (39%) and industrial/agricultural settings (21%). Outbreak size ranged from 2 to 639 cases per outbreak; the median size was four cases per outbreak. Correctional facilities had the largest median outbreak size with 18 cases per outbreak, followed by long-term care facilities with 10 cases per outbreak. During periods of high case incidence, outbreaks may be under-ascertained due to limited public health capacity, or reporting may be biased towards high-risk settings prioritized for testing. Outbreaks reported to CCOSS were dominated by jurisdictions with the largest populations.

Conclusion

The trends illustrate that COVID-19 outbreaks in 2021 were reported most frequently in community settings such as schools; however, the largest outbreaks occurred in congregate living settings. The information gathered from outbreak surveillance complemented case incidence trends and furthered understanding of COVID-19 in Canada.

Third dose of COVID-19 mRNA vaccine closes the gap in immune response between naïve nursing home residents and healthy adults

Background

Nursing home residents, a frail and old population group, respond poorly to primary mRNA COVID-19 vaccination. A third dose has been shown to boost protection against severe disease and death in this immunosenescent population, but limited data is available on the immune responses it induces.

Methods

In this observational cohort study, peak humoral and cellular immune responses were compared 28 days after the second and third doses of the BNT162b2 mRNA COVID-19 vaccine in residents and staff members of two Belgian nursing homes. Only individuals without evidence of previous SARS-CoV-2 infection at third dose administration were included in the study. In addition, an extended cohort of residents and staff members was tested for immune responses to a third vaccine dose and was monitored for vaccine breakthrough infections in the following six months. The trial is registered on ClinicalTrials.gov (NCT04527614).

Findings

All included residents (n=85) and staff members (n=88) were SARS-CoV-2 infection naïve at third dose administration. Historical blood samples from 28 days post second dose were available from 42 residents and 42 staff members. Magnitude and quality of humoral and cellular immune responses were strongly boosted in residents post third compared to post second dose. Increases were less pronounced in staff members than in residents. At 28 days post third dose, differences between residents and staff had become mostly insignificant. Humoral, but not cellular, responses induced by a third dose were predictive of subsequent incidence of vaccine breakthrough infection in the six months following vaccination.

Interpretation

These data show that a third dose of mRNA COVID-19 vaccine largely closes the gap in humoral and cellular immune response observed after primary vaccination between NH residents and staff members but suggest that further boosting might be needed to achieve optimal protection against variants of concern in this vulnerable population group.

Safety and effectiveness of the booster dose of mRNA COVID-19 vaccines in people with multiple sclerosis: A monocentric experience

BACKGROUND

Long-term data on the effectiveness and safety of the booster dose of anti-SARS-CoV-2 vaccines in people affected by multiple sclerosis (pwMS) are lacking, hence a retrospective monocentric study exploring these issues was undertaken.

MATERIALS AND METHODS

PwMS who had received the booster dose of anti-COVID19 mRNA vaccines (either Comirnaty or Spikevax) according to the national regulation were included. The occurrence of adverse events or disease reactivation and SARS-CoV-2 infection were recorded up to last follow-up. Factors predictive of COVID-19 were explored using logistic regression analyses. A two-tailed p-value <0.05 was considered significant.

RESULTS

One hundred and fourteen pwMS were included: 80 females (70%); median age at the booster dose 42 years (range 21 - 73); 106/114 patients (93%) were receiving a disease-modifying treatment at vaccination. The median follow-up after the booster dose was 6 (range 2 - 7) months. Adverse events were experienced in 58% of the patients, being mild to moderate in most cases; 4 reactivations of MS were observed, two of which occurring within 4 weeks after the booster. SARS-CoV-2 infection was reported in 24/114 (21%) cases, occurring a median of 74 days (5-162) after the booster dose and requiring hospitalisation in 2 patients. Six cases received direct antiviral drugs. Age at vaccination and time between the primary vaccination cycle and the booster dose were independently and inversely associated with the risk of COVID-19 (HR 0.95 and 0.98, respectively).

CONCLUSIONS

The administration of the booster dose in pwMS showed an overall good safety profile and protected 79% of the patients from SARS-CoV-2 infection. The observed association between the risk of infection after the booster dose and both younger age at vaccination and shorter interval period to the booster dose suggest that unobserved confounders, possibly including behavioural and social factors, play a relevant role in determining the individual propensity to get infected with COVID-19.

Enhancement of immunogenicity and neutralizing responses against SARS-CoV-2 spike protein using the Fc fusion fragment

AIMS

Vaccination has played an important role in protecting against death and the severity of COVID-19. The recombinant protein vaccine platform has a long track record of safety and efficacy. Here, we fused the SARS-CoV-2 spike S1 subunit to the Fc region of IgG and investigated immunogenicity, reactivity to human vaccinated sera, and neutralizing activity as a candidate protein vaccine.

MATERIALS AND METHOD

We evaluated the immunogenicity of CHO-expressed S1-Fc fusion protein and tag-free S1 protein in rabbits via the production of S1-specific polyclonal antibodies. We subsequently compared the neutralizing activities of sera from immunized rabbits and human-vaccinated individuals using a surrogate Virus Neutralization Test (sVNT).

KEY FINDINGS

The results indicate that S1-specific polyclonal antibodies were induced in all groups; however, antibody levels were higher in rabbits immunized with S1-Fc fusion protein than tag-free S1 protein. Moreover, the reactivity of human vaccinated sera against S1-Fc fusion protein was significantly higher than tag-free S1 protein. Lastly, the results of the virus-neutralizing activity revealed that vaccination with S1-Fc fusion protein induced the highest level of neutralizing antibody response against SARS-CoV-2.

SIGNIFICANCE

Our results demonstrate that the S1 protein accompanied by the Fc fragment significantly enhances the immunogenicity and neutralizing responses against SARS-CoV-2. It is hoped that this platform can be used for human vaccination.

COVID-19 vaccine hesitancy in care home staff: A survey of Liverpool care homes

Uptake of COVID-19 vaccine first doses in UK care homes has been higher among residents compared to staff. We aimed to identify causes of lower COVID-19 vaccine uptake amongst care home staff within Liverpool. An anonymised online survey was distributed to all care home managers, between the 21st and the 29th January 2021. 53 % of 87 care homes responded. The overall COVID-19 vaccination rate was 52.6 % (n = 1119). Reasons, identified by care home managers for staff being unvaccinated included: concerns about lack of vaccine research (37.0 %), staff being off-site during vaccination sessions (36.5 %), pregnancy and fertility concerns (5.6 %), and allergic reactions concerns (3.2 %). Care home managers wanted to tackle vaccine hesitancy through conversations with health professionals, and provision of evidence dispelling vaccine misinformation. Vaccine hesitancy and logistical issues were the main causes for reduced vaccine uptake among care home staff. The former could be addressed by targeted training, and public health communication campaigns to build confidence and acceptance of COVID-19 vaccines.

Development of morbidity and mortality of SARS-CoV-2 in nursing homes for the elderly in Frankfurt am Main, Germany, 2020-2022: What protective measures are still required?

Introduction

Nursing-home residents are among the highest risk group in the SARS-CoV-2 pandemic. At the onset of the SARS-CoV-2 pandemic, the majority of all deaths from or with SARS-CoV-2 occurred in long-term care facilities (LTCFs), so that maximum protective measures were mandated for these facilities. This study analyzed the impact of the new virus variants and the vaccination campaign on disease severity and mortality among nursing home residents and staff through 2022 as a basis for determining which protective measures remain necessary and appropriate.

Methods

In five homes in Frankfurt am Main, Germany, with a total capacity for 705 residents, all cases occurring in the facility among residents and staff were recorded and documented (date of birth and diagnosis, hospitalization and death, vaccination status) and were descriptively analyzed with SPSS.

Results

By 31^st August 2022, 496 residents tested positive for SARS-CoV-2, 93 in 2020, 136 in 2021, and 267 in 2022; 14 residents presented with a second SARS-CoV-2 infection in 2022, having previously experienced an infection in 2020 or 2021. The percentage of hospitalizations decreased from 24.7% (2020) and 17.6% (2021) to 7.5% (2022), and the percentage of deaths decreased from 20.4% and 19.1% to 1.5%. In 2021, 61.8% of those infected were vaccinated (at least 2x); in 2022, 86.2% of residents had been vaccinated twice, 84% of whom had already had a booster vaccination. Hospitalization and death rates were significantly higher among the unvaccinated than the vaccinated throughout all years (unvaccinated 21.5% and 18.0%; vaccinated 9.8% and 5.5%; KW test p=0.000). However, this difference was no longer significant under the prevalence of the Omicron variant in 2022 (unvaccinated 8.3% and 0%; p=0.561; vaccinated 7.4% and 1.7%; p=0.604). From 2020 to 2022, 400 employees were documented as infected, with 25 having second infections in 2022. Only one employee showed a second infection in 2021 following the first in 2020. Three employees were hospitalized; no deaths occurred.

Discussion and conclusion

Severe COVID-19 courses occurred with the Wuhan Wild type in 2020, with a high death rate among nursing-home residents. In contrast, during the waves in 2022 with the relatively mildly pathogenic Omicron variant, many infections but few severe courses and deaths were observed among the now mostly vaccinated and boostered nursing-home residents. Given the high immunity of the population and the low pathogenicity of the circulating virus - even in nursing-home residents - protective measures in nursing homes that restrict people's right to self-determination and quality of life no longer seem justified. Instead, the general hygiene rules and the recommendations of the KRINKO (German Commission for Hospital Hygiene and Infection Prevention) on infection prevention should be followed, and the recommendations of the STIKO (German Standing Commission on Vaccination) on vaccination not only against SARS-CoV-2 but also against influenza and pneumococci should be observed.

Clinical Effectiveness of SARS-CoV-2 Booster Vaccine Against Omicron Infection in Residents and Staff of Long-term Care Facilities: A Prospective Cohort Study (VIVALDI)

Background

Successive severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants have caused severe disease in long-term care facility (LTCF) residents. Primary vaccination provides strong short-term protection, but data are limited on duration of protection following booster vaccines, particularly against the Omicron variant. We investigated the effectiveness of booster vaccination against infections, hospitalizations, and deaths among LTCF residents and staff in England.

Methods

We included residents and staff of LTCFs within the VIVALDI study (ISRCTN 14447421) who underwent routine, asymptomatic testing (December 12, 2021-March 31, 2022). Cox regression was used to estimate relative hazards of SARS-CoV-2 infection, and associated hospitalization and death at 0-13, 14-48, 49-83, 84-111, 112-139, and 140+ days after dose 3 of SARS-CoV-2 vaccination compared with 2 doses (after 84+ days), stratified by previous SARS-CoV-2 infection and adjusting for age, sex, LTCF capacity, and local SARS-CoV-2 incidence.

Results

A total of 14 175 residents and 19 793 staff were included. In residents without prior SARS-CoV-2 infection, infection risk was reduced 0-111 days after the first booster, but no protection was apparent after 112 days. Additional protection following booster vaccination waned but was still present at 140+ days for COVID-associated hospitalization (adjusted hazard ratio [aHR], 0.20; 95% CI, 0.06-0.63) and death (aHR, 0.50; 95% CI, 0.20-1.27). Most residents (64.4%) had received primary course vaccine of AstraZeneca, but this did not impact pre- or postbooster risk. Staff showed a similar pattern of waning booster effectiveness against infection, with few hospitalizations and no deaths.

Conclusions

Our findings suggest that booster vaccination provided sustained protection against severe outcomes following infection with the Omicron variant, but no protection against infection from 4 months onwards. Ongoing surveillance for SARS-CoV-2 in LTCFs is crucial.

Will Omics Biotechnologies Save Us from Future Pandemics? Lessons from COVID-19 for Vaccinomics and Adversomics

The COVID-19 pandemic had cross-cutting impacts on planetary health, quotidian life, and society. Mass vaccination with the current gene-based vaccines has helped control the pandemic but unfortunately it has not shown effectiveness in preventing the spread of the virus. In addition, not all individuals respond to these vaccines, while others develop adverse reactions that cannot be neglected. It is also a fact that some individuals are more susceptible to infection while others develop effective immunization post-infection. We note here that the person-to-person and population variations in vaccine efficacy and side effects have been studied in the field of vaccinomics long before the COVID-19 pandemic. Additionally, the field of adversomics examines the mechanisms of individual differences in the side effects of health interventions. In this review, we discuss the potential of a multi-omics approach for comprehensive profiling of the benefit/risk ratios of vaccines. Vaccinomics and adversomics stand to benefit planetary health and contribute to the prevention of future pandemics in the 21st century by offering precision guidance to clinical trials as well as promoting precision use of vaccines in ways that proactively respond to individual and population differences in their efficacy and safety. This vision of pandemic prevention based on personalized instead of mass vaccination also calls for equity in access to precision vaccines and diagnostics that support a vision and practice of vaccinomics and adversomics in planetary health.

The impact of dementia, frailty and care home characteristics on SARS-CoV-2 incidence in a national cohort of Welsh care home residents during a period of high community prevalence

BACKGROUND

dementia may increase care home residents' risk of COVID-19, but there is a lack of evidence on this effect and on interactions with individual and care home-level factors.

METHODS

we created a national cross-sectional retrospective cohort of care home residents in Wales for 1 September to 31 December 2020. Risk factors were analysed using multi-level logistic regression to model the likelihood of SARS-CoV-2 infection and mortality.

RESULTS

the cohort included 9,571 individuals in 673 homes. Dementia was diagnosed in 5,647 individuals (59%); 1,488 (15.5%) individuals tested positive for SARS-CoV-2. We estimated the effects of age, dementia, frailty, care home size, proportion of residents with dementia, nursing and dementia services, communal space and region. The final model included the proportion of residents with dementia (OR for positive test 4.54 (95% CIs 1.55-13.27) where 75% of residents had dementia compared to no residents with dementia) and frailty (OR 1.29 (95% CIs 1.05-1.59) for severe frailty compared with no frailty). Analysis suggested 76% of the variation was due to setting rather than individual factors. Additional analysis suggested severe frailty and proportion of residents with dementia was associated with all-cause mortality, as was dementia diagnosis. Mortality analyses were challenging to interpret.

DISCUSSION

whilst individual frailty increased the risk of COVID-19 infection, dementia was a risk factor at care home but not individual level. These findings suggest whole-setting interventions, particularly in homes with high proportions of residents with dementia and including those with low/no individual risk factors may reduce the impact of COVID-19.

Managing the Impact of COVID-19 in Nursing Homes and Long-Term Care Facilities: An Update

Older adults in nursing homes are at greatest risk of morbidity and mortality from SARS-CoV-2 infection. Nursing home residents constituted one-third to more than half of all deaths during the early waves of the COVID-19 pandemic. Following this, widespread adaptation of infection prevention and control measures and the supply and use of personal protective equipment resulted in a significant decrease in nursing home infections and deaths. For nursing homes, the most important determinant of experiencing a SARS-CoV-2 outbreak in the first instance appears to be community-transmission levels (particularly with variants of concern), although nursing home size and quality, for-profit status, and sociodemographic characteristics are also important. Use of visitation bans, imposed to reduce the impact of COVID-19 on residents, must be delicately balanced against their impact on resident, friend or family, and staff well-being. The successful rollout of primary vaccination has resulted in a sharp decrease in morbidity and mortality from SARS-CoV-2 in nursing homes. However, emerging evidence suggests that vaccine efficacy may wane over time, and the use of a third or additional vaccine "booster" doses in nursing home residents restores protection afforded by primary vaccination. Ongoing monitoring of vaccine efficacy in terms of infection, morbidity, and mortality is crucial in this vulnerable group in informing ongoing SARS-CoV-2 vaccine boosting strategies. Here, we detail the impact of SARS-CoV-2 on nursing home residents and discuss important considerations in the management of nursing home SARS-CoV-2 outbreaks. We additionally examine the use of testing strategies, nonpharmacologic outbreak control measures and vaccination strategies in this cohort. Finally, the impact of SARS-CoV-2 on the sector is reflected on as we emphasize the need for adoption of universal standards of medical care and integration with wider public health infrastructure in nursing homes in order to provide a safe and effective long-term care sector.