Influenza vaccination in immunocompromised patients: efficacy and safety

Predictors of Severity of Influenza-Related Hospitalizations: Results From the Global Influenza Hospital Surveillance Network (GIHSN)

BACKGROUND

The Global Influenza Hospital Surveillance Network (GIHSN) has since 2012 provided patient-level data on severe influenza-like-illnesses from >100 participating clinical sites worldwide based on a core protocol and consistent case definitions.

METHODS

We used multivariable logistic regression to assess the risk of intensive care unit admission, mechanical ventilation, and in-hospital death among hospitalized patients with influenza and explored the role of patient-level covariates and country income level.

RESULTS

The data set included 73 121 patients hospitalized with respiratory illness in 22 countries, including 15 660 with laboratory-confirmed influenza. After adjusting for patient-level covariates we found a 7-fold increase in the risk of influenza-related intensive care unit admission in lower middle-income countries (LMICs), compared with high-income countries (P = .01). The risk of mechanical ventilation and in-hospital death also increased by 4-fold in LMICs, though these differences were not statistically significant. We also find that influenza mortality increased significantly with older age and number of comorbid conditions. Across all severity outcomes studied and after controlling for patient characteristics, infection with influenza A/H1N1pdm09 was more severe than with A/H3N2.

CONCLUSIONS

Our study provides new information on influenza severity in underresourced populations, particularly those in LMICs.

A meta-analysis of immunogenicity and safety of two versus single-doses of influenza A (H1N1) vaccine in person living with HIV

Purpose: Influenza vaccination of person living with HIV (PLWH) is a powerful means to tackle severe clinical outcomes. Few data on two doses of influenza vaccine in PLWH are available.Research Design: To evaluate the immunogenicity and safety of two doses of vaccine as compared with single dose in PLWH, we searched Pubmed, Embase, and web of science databases for relevant articles (January 2009 to April 2023). Pooled SMD or RR and 95% CI were calculated.Results: A total of 2436 participants from 14 studies were included. Compared to single dose influenza vaccine regimen, the pooled RR of seroprotection and seroconversion for two doses of vaccines was 1.14 (95%CI: 1.08-1.21) and 1.25 (95%CI: 1.16-1.34), respectively; the SMD of GMT was 0.42 (95%CI: 0.35, 0.49). Regarding safety, the fever risk in PLWH receiving two doses of vaccine was 3.42 fold higher than that of single dose vaccine, and the risk of myalgia had a quarter reduction. No serious vaccine-related adverse events were reported.Conclusions: Collectively, two doses of the vaccine are associated with a better immunogenicity and an acceptable safety in PLWH. Two doses of the adjuvant vaccination might be a superior vaccination regimen.nation regimen.

Immunogenicity of an adjuvanted broadly active influenza vaccine in immunocompromised and diverse populations

Influenza virus outbreaks are a major burden worldwide each year. Current vaccination strategies are inadequate due to antigenic drift/shift of the virus and the elicitation of low immune responses. The use of computationally optimized broadly reactive antigen (COBRA) hemagglutinin (HA) immunogens subvert the constantly mutating viruses; however, they are poorly immunogenic on their own. To increase the immunogenicity of subunit vaccines such as this, adjuvants can be delivered with the vaccine. For example, agonists of the stimulator of interferon genes (STING) have proven efficacy as vaccine adjuvants. However, their use in high-risk populations most vulnerable to influenza virus infection has not been closely examined. Here, we utilize a vaccine platform consisting of acetalated dextran microparticles loaded with COBRA HA and the STING agonist cyclic GMP-AMP. We examine the immunogenicity of this platform in mouse models of obesity, aging, and chemotherapy-induced immunosuppression. Further, we examine vaccine efficacy in collaborative cross mice, a genetically diverse population that mimics human genetic heterogeneity. Overall, this vaccine platform had variable efficacy in these populations supporting work to better tailor adjuvants to specific populations.

Interim Influenza Vaccine Effectiveness Against Laboratory-Confirmed Influenza - California, October 2023-January 2024

Surveillance data can provide rapid, within-season influenza vaccine effectiveness (VE) estimates to guide public health recommendations. Mandatory reporting of influenza vaccine administration to California's immunization information registry began January 1, 2023, and mandatory reporting of all influenza laboratory test results, including negative results, was instituted in California on June 15, 2023. These data, collected by the California Department of Public Health during October 1, 2023-January 31, 2024, were used to calculate interim influenza VE against laboratory-confirmed influenza by comparing the odds of vaccination among case-patients (persons who received a positive influenza laboratory test result) and control patients (those who received a negative influenza laboratory test result). VE was calculated as 1 - adjusted odds ratio using mixed-effects logistic regression, with age, race, and ethnicity as fixed effects and specimen collection week and county as random effects. Overall, during October 1, 2023-January 31, 2024, estimated VE was 45% among persons aged ≥6 months, 56% among children and adolescents aged 6 months-17 years, 48% among adults aged 18-49 years, 36% among those aged 50-64 years, and 30% among those aged ≥65 years. Consistent with some previous influenza seasons, influenza vaccination provided moderate protection against laboratory-confirmed influenza among infants, children, adolescents, and adults. All persons aged ≥6 months without a contraindication to vaccination should receive annual influenza vaccination to reduce influenza illness, severe influenza, and strain on health care resources. Influenza vaccination remains the best way to prevent influenza.

Influenza vaccine coverage in 6months-64 years-old patients affected by chronic diseases: A retrospective cohort study in Italy

At the beginning of each flu season, the Italian Ministry of Health defines the categories at higher risk of influenza complications, for which vaccination is actively and freely offered. The vaccine coverage (VC) of the influenza vaccine in subjects from 6 months to 64 years of age suffering from diseases that increase the risk of complications from influenza during the 2020-2021 season was evaluated. Our study wants to evaluate the VCs of the influenza vaccine in these subjects during the 2020/2021 season in Apulia. The digital archives relative to the Apulian population were used. A retrospective cohort study design was performed. 484,636 Apulian residents aged between 6 months and 64 years suffered from at least one chronic disease; 139,222 of 484,636 subjects received the influenza vaccine (VC: 28.7%) from October 2020 to January 2021. Considering the single comorbidities, the greatest values are found for pathologies for which major surgical interventions are planned and chronic renal failure/adrenal insufficiency patients, while the worst for chronic liver diseases and pathologies for which major surgical interventions are planned. In any case, it would seem that better VC is achieved in subjects with more than one chronic condition. Influenza vaccination must be promoted as a central public health measure, also because by reducing the burden on hospitals, it can greatly benefit the management of COVID-19 patients. Greater efforts by public health institutions must be implemented in order to achieve better VC in the target categories, including chronic patients.

Systemic and T cell-associated responses to SARS-CoV-2 immunisation in gut inflammation (STAR SIGN study): effects of biologics on vaccination efficacy of the third dose of mRNA vaccines against SARS-CoV-2

BACKGROUND

Immunosuppressed patients with inflammatory bowel disease (IBD) experience increased risk of vaccine-preventable diseases such as COVID-19.

AIMS

To assess humoral and cellular immune responses following SARS-CoV-2 booster vaccination in immunosuppressed IBD patients and healthy controls.

METHODS

In this prospective, multicentre, case-control study, 139 IBD patients treated with biologics and 110 healthy controls were recruited. Serum anti-SARS-CoV-2 spike IgG concentrations were measured 2-16 weeks after receiving a third mRNA vaccine dose. The primary outcome was to determine if humoral immune responses towards booster vaccines differ in IBD patients under anti-TNF versus non-anti-TNF therapy and healthy controls. Secondary outcomes were antibody decline, impact of previous infection and SARS-CoV-2-targeted T cell responses.

RESULTS

Anti-TNF-treated IBD patients showed reduced anti-spike IgG concentrations (geometric mean 2357.4 BAU/ml [geometric SD 3.3]) when compared to non-anti-TNF-treated patients (5935.7 BAU/ml [3.9]; p < 0.0001) and healthy controls (5481.7 BAU/ml [2.4]; p < 0.0001), respectively. In multivariable modelling, prior infection (geometric mean ratio 2.00 [95% CI 1.34-2.90]) and vaccination with mRNA-1273 (1.53 [1.01-2.27]) increased antibody concentrations, while anti-TNF treatment (0.39 [0.28-0.54]) and prolonged time between vaccination and antibody measurement (0.72 [0.58-0.90]) decreased anti-SARS-CoV-2 spike antibodies. Antibody decline was comparable in IBD patients independent of anti-TNF treatment and antibody concentrations could not predict breakthrough infections. Cellular and humoral immune responses were uncoupled, and more anti-TNF-treated patients than healthy controls developed inadequate T cell responses (15/73 [20.5%] vs 2/100 [2.0%]; p = 0.00031).

CONCLUSIONS

Anti-TNF-treated IBD patients have impaired humoral and cellular immunogenicity following SARS-CoV-2 booster vaccination. Fourth dose administration may be beneficial for these patients.

Safety and immunogenicity of COVID-19 vaccination in immunocompromised patients

ABSTRACT

The coronavirus disease 2019 (COVID-19) pandemic poses a great threat to public health. Individuals who are immunocompromised because of the progression of the primary disease or receiving immunosuppressive medications are prone to severe COVID-19 complications and poor outcomes. Abundant data have shown that many COVID-19 vaccines are safe and effective in large-scale populations; however, these clinical trials have excluded immunocompromised populations. Available evidence indicates that immunocompromised populations have a blunted immune response to other vaccines, raising concerns regarding the efficacy of COVID-19 vaccination in these populations. Thus, there is an urgent need to delineate the efficacy of COVID-19 vaccines in these vulnerable populations. Here, we review the characteristics of specific humoral and cellular responses to COVID-19 vaccination in immunocompromised populations, including HIV-infected patients and those receiving immunosuppressive treatment, especially solid organ transplant recipients and those undergoing anti-CD20 treatment. We also addressed the challenges that immunocompromised populations will face in the future pandemic and the need for basic and clinical translational studies to highlight the best vaccination strategies for these populations.

Magnitude and breadth of antibody cross-reactivity induced by recombinant influenza hemagglutinin trimer vaccine is enhanced by combination adjuvants

The effects of adjuvants for increasing the immunogenicity of influenza vaccines are well known. However, the effect of adjuvants on increasing the breadth of cross-reactivity is less well understood. In this study we have performed a systematic screen of different toll-like receptor (TLR) agonists, with and without a squalene-in-water emulsion on the immunogenicity of a recombinant trimerized hemagglutinin (HA) vaccine in mice after single-dose administration. Antibody (Ab) cross-reactivity for other variants within and outside the immunizing subtype (homosubtypic and heterosubtypic cross-reactivity, respectively) was assessed using a protein microarray approach. Most adjuvants induced broad IgG profiles, although the response to a combination of CpG, MPLA and AddaVax (termed 'IVAX-1') appeared more quickly and reached a greater magnitude than the other formulations tested. Antigen-specific plasma cell labeling experiments show the components of IVAX-1 are synergistic. This adjuvant preferentially stimulates CD4 T cells to produce Th1>Th2 type (IgG2c>IgG1) antibodies and cytokine responses. Moreover, IVAX-1 induces identical homo- and heterosubtypic IgG and IgA cross-reactivity profiles when administered intranasally. Consistent with these observations, a single-cell transcriptomics analysis demonstrated significant increases in expression of IgG1, IgG2b and IgG2c genes of B cells in H5/IVAX-1 immunized mice relative to naïve mice, as well as significant increases in expression of the IFNγ gene of both CD4 and CD8 T cells. These data support the use of adjuvants for enhancing the breath and durability of antibody responses of influenza virus vaccines.

Efficacy of covid-19 vaccines in immunocompromised patients: systematic review and meta-analysis

OBJECTIVE

To compare the efficacy of covid-19 vaccines between immunocompromised and immunocompetent people.

DESIGN

Systematic review and meta-analysis.

DATA SOURCES

PubMed, Embase, Central Register of Controlled Trials, COVID-19 Open Research Dataset Challenge (CORD-19), and WHO covid-19 databases for studies published between 1 December 2020 and 5 November 2021. ClinicalTrials.gov and the WHO International Clinical Trials Registry Platform were searched in November 2021 to identify registered but as yet unpublished or ongoing studies.

STUDY SELECTION

Prospective observational studies comparing the efficacy of covid-19 vaccination in immunocompromised and immunocompetent participants.

METHODS

A frequentist random effects meta-analysis was used to separately pool relative and absolute risks of seroconversion after the first and second doses of a covid-19 vaccine. Systematic review without meta-analysis of SARS-CoV-2 antibody titre levels was performed after first, second, and third vaccine doses and the seroconversion rate after a third dose. Risk of bias and certainty of evidence were assessed.

RESULTS

82 studies were included in the meta-analysis. Of these studies, 77 (94%) used mRNA vaccines, 16 (20%) viral vector vaccines, and 4 (5%) inactivated whole virus vaccines. 63 studies were assessed to be at low risk of bias and 19 at moderate risk of bias. After one vaccine dose, seroconversion was about half as likely in patients with haematological cancers (risk ratio 0.40, 95% confidence interval 0.32 to 0.50, I²=80%; absolute risk 0.29, 95% confidence interval 0.20 to 0.40, I²=89%), immune mediated inflammatory disorders (0.53, 0.39 to 0.71, I²=89%; 0.29, 0.11 to 0.58, I²=97%), and solid cancers (0.55, 0.46 to 0.65, I²=78%; 0.44, 0.36 to 0.53, I²=84%) compared with immunocompetent controls, whereas organ transplant recipients were 16 times less likely to seroconvert (0.06, 0.04 to 0.09, I²=0%; 0.06, 0.04 to 0.08, I²=0%). After a second dose, seroconversion remained least likely in transplant recipients (0.39, 0.32 to 0.46, I²=92%; 0.35, 0.26 to 0.46), with only a third achieving seroconversion. Seroconversion was increasingly likely in patients with haematological cancers (0.63, 0.57 to 0.69, I²=88%; 0.62, 0.54 to 0.70, I²=90%), immune mediated inflammatory disorders (0.75, 0.69 to 0.82, I²=92%; 0.77, 0.66 to 0.85, I²=93%), and solid cancers (0.90, 0.88 to 0.93, I²=51%; 0.89, 0.86 to 0.91, I²=49%). Seroconversion was similar between people with HIV and immunocompetent controls (1.00, 0.98 to 1.01, I²=0%; 0.97, 0.83 to 1.00, I²=89%). Systematic review of 11 studies showed that a third dose of a covid-19 mRNA vaccine was associated with seroconversion among vaccine non-responders with solid cancers, haematological cancers, and immune mediated inflammatory disorders, although response was variable in transplant recipients and inadequately studied in people with HIV and those receiving non-mRNA vaccines.

CONCLUSION

Seroconversion rates after covid-19 vaccination were significantly lower in immunocompromised patients, especially organ transplant recipients. A second dose was associated with consistently improved seroconversion across all patient groups, albeit at a lower magnitude for organ transplant recipients. Targeted interventions for immunocompromised patients, including a third (booster) dose, should be performed.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42021272088.

Acute and chronic inflammatory neuropathies and COVID-19 vaccines: Practical recommendations from the task force of the Italian Peripheral Nervous System Association (ASNP)

BACKGROUND AND AIMS

To develop recommendations for vaccination for coronavirus-19 (COVID-19) in patients with inflammatory neuropathies.

METHODS

Key questions were formulated in order to perform a literature review on the safety and efficacy of vaccines in patients with inflammatory neuropathies. Based on the best evidence and expert opinion, a list of recommendations was formulated to inform decision on vaccination for COVID-19 in patients with inflammatory neuropathies and increase adherence to vaccination programmes.

RESULTS

Recommendations addressing safety and efficacy of vaccination in patients with inflammatory neuropathies were formulated. No data are currently available on the safety and efficacy of COVID-19 vaccines in patients with inflammatory neuropathies or other immune-mediated conditions. There is only sparse data on the safety of previous available vaccines in patients with inflammatory neuropathies, but studies on other autoimmune disorders indicate that these are safe and mostly efficacious. Patients with inflammatory neuropathies might be at increased risk for severe illness from COVID-19.

INTERPRETATION

Patients with inflammatory neuropathies should be encouraged to adhere to the vaccination campaign for COVID-19. These recommendations provide guidance on the management of vaccinations for COVID-19 in patients with inflammatory neuropathies. More research is needed regarding the safety and efficacy of vaccination in patients with inflammatory neuropathies and other immune conditions.

Cocoon vaccination for influenza in patients with a solid tumor: a retrospective study

Purpose

Oncological patients are susceptible to various severe viral infections, including influenza. Vaccinating oncological patients and their household contacts (“cocoon vaccination”) may protect these patients from contracting influenza. To understand the potential of cocoon vaccination in oncological patients, this study assesses the influenza vaccination status of oncological patients and their household contacts and their considerations regarding the vaccination.

Methods

In this retrospective study, oncological patients with a solid tumor were asked to fill in a questionnaire about their own and their household contacts’ influenza vaccination status in the influenza season of 2018–2019.

Results

Ninety-eight patients were included (response rate 88%). The influenza vaccination rates of oncological patients and their first household contacts were 43.9% and 44.9%, respectively. The majority of vaccinated patients and vaccinated first household contacts had been advised by their general practitioner to get the vaccination. A minority of the first household contacts reported getting vaccinated specifically because of the patient’s vulnerability. Unvaccinated patients and unvaccinated household contacts mainly believed the vaccination was unnecessary or were afraid of side effects. None of the included patients had been hospitalized with influenza.

Conclusion

The oncological patients’ and first household contacts’ vaccination rates in this study were lower than the vaccination rates of the general Dutch population of over 60 years old, possibly due to a lack of knowledge and misconceptions about the vaccination. Further research is required to establish whether cocoon vaccination can contribute to protecting oncological patients from contracting an influenza infection.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00520-020-05883-2.

Carrot Pomace Polysaccharide (CPP) Improves Influenza Vaccine Efficacy in Immunosuppressed Mice via Dendritic Cell Activation

Despite the advancements in vaccination research and practices, influenza viruses remain a global health concern. Inducing a robust immune response by vaccination is especially challenging in the elderly, the immunocompromised, and persons with chronic illnesses. Polysaccharides derived from food may act as a safe and readily accessible means to boost the immune system during vaccination. In this study, we investigated whether crude polysaccharides derived from carrot pomace (CPP) could stimulate innate immune cell function and promote influenza vaccine immunogenicity. In bone marrow-derived dendritic cells (BMDCs), CPP increased the fraction of CD11c+MHCII+ cells and the expression of co-stimulatory molecules CD40 and CD80, indicative of enhanced maturation and activation. Functionally, CPP-treated BMDCs promoted inflammatory cytokine production in splenic lymphocytes. In a mouse model of immunosuppression induced by cyclophosphamide, animals given CPP before and after an influenza vaccine challenge showed increased frequencies of dendritic cells and natural killer cells in the spleen, in addition to the recovery of vaccine-specific antibody titers. Moreover, innate myeloid cells in CPP-fed mice showed evidence of phenotypic modification via markedly enhanced interleukin(IL)-12 and interferon(IFN)-γ production in response to lipopolysaccharide(LPS) stimulation ex vivo. Our findings suggest that the administration of carrot pomace polysaccharides can significantly enhance the efficacy of influenza vaccination.

Targeting the IL-22/IL-22BP axis enhances tight junctions and reduces inflammation during influenza infection

The seasonal burden of influenza coupled with the pandemic outbreaks of more pathogenic strains underscore a critical need to understand the pathophysiology of influenza injury in the lung. Interleukin-22 (IL-22) is a promising cytokine that is critical in protecting the lung during infection. This cytokine is strongly regulated by the soluble receptor IL-22-binding protein (IL-22BP), which is constitutively expressed in the lungs where it inhibits IL-22 activity. The IL-22/IL-22BP axis is thought to prevent chronic exposure of epithelial cells to IL-22. However, the importance of this axis is not understood during an infection such as influenza. Here we demonstrate through the use of IL-22BP-knockout mice (il-22ra2-/-) that a pro-IL-22 environment reduces pulmonary inflammation during H1N1 (PR8/34 H1N1) infection and protects the lung by promoting tight junction formation. We confirmed these results in normal human bronchial epithelial cells in vitro demonstrating improved membrane resistance and induction of the tight junction proteins Cldn4, Tjp1, and Tjp2. Importantly, we show that administering recombinant IL-22 in vivo reduces inflammation and fluid leak into the lung. Taken together, our results demonstrate the IL-22/IL-22BP axis is a potential targetable pathway for reducing influenza-induced pneumonia.

Immunogenicity of high-dose trivalent inactivated influenza vaccine: a systematic review and meta-analysis

INTRODUCTION

High-dose trivalent, inactivated, split-virus influenza vaccine (IIV3-HD) has been available in the US since 2009 for adults aged ≥ 65 years. To better understand how IIV3-HD provides improved protection against influenza, we systematically reviewed clinical studies comparing immune responses to IIV3-HD and standard-dose trivalent vaccine (IIV3-SD).

AREAS COVERED

The primary objective was to determine the relative hemagglutination inhibition (HAI) antibody response of IIV3-HD vs. IIV3-SD in adults aged ≥ 65 years. Based on seven randomized studies including more than 18,500 adults aged ≥ 65 years, combined HAI geometric mean titer (GMT) ratios (95% confidence interval) approximately 1 month post-vaccination were 1.74 (1.65-1.83) for influenza A/H1N1, 1.84 (1.73-1.95) for influenza A/H3N2, and 1.47 (1.36-1.58) for influenza B. HAI GMT ratios in these studies were similar irrespective of sex, older age (≥ 75 years), frailty, and underlying conditions. Trends were similar for A/H3N2 neutralization and anti-neuraminidase antibody titers. In immunocompromised individuals, HAI GMT ratios were mostly > 1.

EXPERT OPINION

In agreement with its improved efficacy and effectiveness, IIV3-HD is consistently more immunogenic than IIV3-SD in adults aged ≥ 65 years. IIV3-HD also appears more immunogenic in immunocompromised individuals.

The Elusive Anti-Candida Vaccine: Lessons From the Past and Opportunities for the Future

Candidemia is a bloodstream fungal infection caused by Candida species and is most commonly observed in hospitalized patients. Even with proper antifungal drug treatment, mortality rates remain high at 40–50%. Therefore, prophylactic or preemptive antifungal medications are currently recommended in order to prevent infections in high-risk patients. Moreover, the majority of women experience at least one episode of vulvovaginal candidiasis (VVC) throughout their lifetime and many of them suffer from recurrent VVC (RVVC) with frequent relapses for the rest of their lives. While there currently exists no definitive cure, the only available treatment for RVVC is again represented by antifungal drug therapy. However, due to the limited number of existing antifungal drugs, their associated side effects and the increasing occurrence of drug resistance, other approaches are greatly needed. An obvious prevention measure for candidemia or RVVC relapse would be to immunize at-risk patients with a vaccine effective against Candida infections. In spite of the advanced and proven techniques successfully applied to the development of antibacterial or antiviral vaccines, however, no antifungal vaccine is still available on the market. In this review, we first summarize various efforts to date in the development of anti-Candida vaccines, highlighting advantages and disadvantages of each strategy. We next unfold and discuss general hurdles encountered along these efforts, such as the existence of large genomic variation and phenotypic plasticity across Candida strains and species, and the difficulty in mounting protective immune responses in immunocompromised or immunosuppressed patients. Lastly, we review the concept of “trained immunity” and discuss how induction of this rapid and nonspecific immune response may potentially open new and alternative preventive strategies against opportunistic infections by Candida species and potentially other pathogens.

Antiviral resistance due to deletion in the neuraminidase gene and defective interfering-like viral polymerase basic 2 RNA of influenza A virus subtype H3N2

BACKGROUND AND OBJECTIVE

Antiviral treatment of influenza virus infections can lead to drug resistance of virus. This study investigates a selection of mutations in the full genome of H3N2 influenza A virus isolated from a patient in treatment with oseltamivir.

STUDY DESIGN

Respiratory samples from a patient were collected before, during, and after antiviral treatment. Whole genome sequencing of the influenza virus by next generation sequencing, and low-frequency-variant analysis was performed. Neuraminidase-inhibition tests were performed with oseltamivir and zanamivir, and viruses were propagated in sial-transferase gene transfected Madin-Darby Canine Kidney cells.

RESULTS

A deletion at amino acid position 245-248 in the neuraminidase gene occurred after initiation of treatment with oseltamivir. The deleted virus had highly reduced inhibition against oseltamivir but was sensitive to zanamivir. Nine days after discontinuation of oseltamivir treatment the deleted H3N2 virus was still present in the patient. After three passages of the deleted virus in cell culture, the deletion was retained. Several variant mutations appeared in the other genes of the H3N2 virus, where most striking were two major out-of-frame deletions in the polymerase basic 2 (PB2) gene, indicating defective interfering-like viral RNA.

CONCLUSIONS

The viruses harboring the 245-248 deletion in the neuraminidase gene were still present after discontinuation of oseltamivir treatment and passages in cell cultures, indicating a potential risk for transmission of the deleted virus. Full genome deep sequencing was useful to reveal variant mutations that might be selected due to antiviral treatment, and defective interfering-like viral PB2 RNA in the respiratory samples was detected.

Respiratory RNA Viruses

Acute upper and lower respiratory infections are a major public health problem and a leading cause of morbidity and mortality worldwide. At greatest risk are young children, the elderly, the chronically ill, and those with suppressed or compromised immune systems. Viruses are the predominant cause of respiratory tract illnesses and include RNA viruses such as respiratory syncytial virus, influenza virus, parainfluenza virus, metapneumovirus, rhinovirus, and coronavirus. Laboratory testing is required for a reliable diagnosis of viral respiratory infections, as a clinical diagnosis can be difficult since signs and symptoms are often overlapping and not specific for any one virus. Recent advances in technology have resulted in the development of newer diagnostic assays that offer great promise for rapid and accurate detection of respiratory viral infections. This chapter emphasizes the fundamental characteristics and clinical importance of the various RNA viruses that cause upper and lower respiratory tract diseases in the immunocompromised host. It highlights the laboratory methods that can be used to make a rapid and definitive diagnosis for the greatest impact on the care and management of ill patients, and the prevention and control of hospital-acquired infections and community outbreaks.

Development of oseltamivir and zanamivir resistance in influenza A(H1N1)pdm09 virus, Denmark, 2014

Antiviral treatment of immunocompromised patients with prolonged influenza virus infection can lead to multidrug resistance. This study reveals the selection of antiviral resistance mutations in influenza A(H1N1)pdm09 virus in an immunocompromised patient during a 6-month period. The patient was treated with two courses of oseltamivir (5 days and 2 months, respectively), with the first course starting at symptom onset, and subsequently zanamivir (2 months and 10 days, respectively). Respiratory samples were investigated by Sanger and next generation sequencing (NGS) and, for NGS data, low-frequency-variant-detection analysis was performed. Neuraminidase-inhibition tests were conducted for samples isolated in Madin-Darby canine kidney cells. In a sample collected 15 days after the end of the first treatment with oseltamivir (Day 20 post-symptom onset), oseltamivir resistance was detected (mutation H275Y with 60.3% frequency by NGS). Day 149 when the patient had almost completed the second zanamivir treatment, mixes of the following resistance mutations were detected; H275Y(65.1%), I223R(9.2%), and E119G(89.6%), accompanied by additional mutations, showing a more complex viral population in the long-term treated patient. Two samples obtained on Day 151 from bronchoalveolar lavage (BAL) and nasopharyngeal swab, respectively, showed different mutation profiles, with a higher frequency of antiviral resistance mutations in BAL. The results emphasise the importance of timely antiviral resistance testing both for treatment of individual patients as well as for preventive measures to control the development and transmission of antiviral resistant viruses.

Vaccination recommendations for the adult immunosuppressed patient: A systematic review and comprehensive field synopsis

BACKGROUND

Immunosuppressed patients are at risk of severe viral infections-related complications. National and international vaccination guidelines have been developed to decrease the mortality risk associated with these infections. However, a summary of these guidelines and the value of immunisation in this population is missing.

OBJECTIVES

To summarize specific guidelines regarding vaccination in immunosuppressed patients.

METHODS

We performed a literature search based on last update vaccine guidelines in immunosuppressed adult patients published between 1/1/2005-1/31/2016 in English or French language using PubMed, Cochrane and Embase, as well as relevant medical society websites.

RESULTS

Of the 389 citations identified, 12 guidelines were selected Three additional guidelines were selected by searching on the websites from medical societies of each specialty. 15 guidelines were included, involving 19 medical societies issued from the US (n = 6), international collaboration (n = 3), UK (n = 2), Canada (n = 1), Australia (n = 1), France (n = 1), and Germany (n = 1). These guidelines provide recommendations on vaccination in asplenic patients (n = 5), cancer patients (n = 4), HIV patients (n = 5), hematopoietic stem cell recipients (n = 4), inflammatory bowel diseases patients (n = 5), psoriasis patients (n = 4), primary immunocompromised patients (n = 3), inflammatory rheumatic diseases patients (n = 6), and solid organ transplant recipients (n = 5). All guidelines recommended pneumococcal and injectable influenza vaccines. Other inactivated vaccines were recommended only in high risk patients. Live vaccines were usually contraindicated in patients under immunosuppressive therapy and/or in HIV patients with a CD4 count under 200/mm³.

CONCLUSION

Pneumococcal and injectable influenza are the two essential vaccines recommended in all immunocompromised patients. Other inactivated vaccines are only indicated in high risk patients. Live vaccines are usually contraindicated.

Vaccination in the primary care setting: when is it safe to proceed?

Primary care practitioners play an important role in administering and advocating vaccinations against vaccine-preventable infectious diseases and ensuring herd immunity in our population. This is a follow-up article to an earlier one which dealt with the principles of vaccine scheduling and administration. This article describes several false contraindications to vaccination that a primary care practitioner may encounter, including pregnancy, current breastfeeding, history of febrile seizures, and having immunosuppressed or pregnant household contacts. We aimed to provide a guide for safe and timely vaccine administration in the primary care setting.

Fluzone® High-Dose Influenza Vaccine

INTRODUCTION

Fluzone® High-Dose (IIV3-HD) is a trivalent, inactivated, split-virus influenza vaccine indicated for use in older adults (≥65 years of age). It contains 60 µg hemagglutinin of each influenza strain, which is four times the hemagglutinin content of standard-dose influenza vaccines, including Fluzone (IIV3-SD). IIV3-HD has been licensed for use in older adults in the US since December 2009 and in Canada since February 2016. Areas covered: In this review, we summarize postlicensure studies on the immunogenicity, safety, and effectiveness of IIV3-HD and estimates of its cost-effectiveness in older adults. We also discuss the potential application of IIV3-HD in adults 50-64 years of age and in individuals who may respond poorly to standard-dose influenza vaccines. Expert commentary: Multiple studies conducted since 2004 have consistently shown that, in older adults, IIV3-HD induces substantially greater antibody responses and better protection against influenza and influenza-associated hospitalization than IIV3-SD. Health economic analyses suggest that IIV3-HD can be a cost-effective alternative to standard-dose trivalent or quadrivalent inactivated influenza vaccines and can even be cost-saving compared to IIV3-SD in older adults. Further investigation of IIV3-HD vaccination as a way to improve immune responses and protection against influenza in immunocompromised individuals is warranted.

Influenza and End-Stage Renal Disease: A Fatal Combination

Influenza epidemics are a major health care problem in the United States causing significant morbidity and mortality. Influenza can occur in all individuals, but immunocompromized hosts and those with chronic diseases such as end-stage renal disease are more susceptible to its fatal complications. Influenza though is largely preventable with the availability of highly efficacious vaccines. Despite the wide array of vaccine types available, the vaccination rates remain dismal, thereby leading to high incidence of the disease. In this report, we discuss a case of an unvaccinated patient with end-stage renal disease who contracted the influenza virus with fatal consequences. This report discusses multiple factors that allowed for a highly preventable disease to cause this negative outcome and provides suggestions to prevent such outcomes in the future.

Effect of the adjuvanted (AS03) A/H1N1 2009 pandemic influenza vaccine on the risk of rejection in solid organ transplant recipients in England: a self-controlled case series

OBJECTIVE

To assess the risk of solid organ transplant (SOT) rejection after vaccination with the adjuvanted (AS03) A/H1N1 2009 pandemic influenza vaccine Pandemrix.

DESIGN

Self-controlled case series (SCCS) in the UK Clinical Practice Research Datalink (CPRD) and its linked component of the Hospital Episodes Statistics (HES) inpatient database. Analyses were conducted using the SCCS method for censored, perturbed or curtailed post-event exposure.

PARTICIPANTS

Of the 184 transplant recipients having experienced at least one SOT rejection (liver, kidney, lung, heart or pancreas) during the study period from 1 October 2009 to 31 October 2010, 91 participants were included in the main analysis, of which 71 had been exposed to Pandemrix.

MAIN OUTCOME MEASURES

Occurrence of SOT rejection during risk (30 and 60 days after any Pandemrix dose) and control periods. Covariates in the CPRD included time since transplantation, seasonal influenza vaccination, bacterial and viral infections, previous SOT rejections and malignancies.

RESULTS

The relative incidence (RI) of rejection of any one of the five transplanted organs, adjusted for time since transplantation, was 1.05 (95% CI 0.52 to 2.14) and 0.80 (95% CI 0.42 to 1.50) within 30 and 60 days after vaccination, respectively. Similar estimates were observed for rejection of a kidney only, the most commonly transplanted organ (RI within 30 days after vaccination: 0.85 (95% CI 0.38 to 1.90)). Across various models and sensitivity analyses, RI estimates remained stable and within a consistent range around 1.0.

CONCLUSIONS

These results suggest a reassuring safety profile for Pandemrix with regard to the risk of rejection in SOT recipients in England and contribute to inform the benefit-risk of AS03-adjuvanted pandemic influenza vaccines in transplanted patients in the event of future pandemics.

TRIAL REGISTRATION NUMBER

NCT01715792.

Recombinant hemagglutinin protein vaccine: a new option in immunization against influenza

Influenza continues to be a major cause of morbidity and mortality worldwide. Vaccination is the most effective strategy to prevent influenza complications. Traditional influenza vaccines rely on an egg-based production system that has several limitations like dependence on egg supply, long production time and contraindication in people with severe egg allergy. Alternative vaccine production systems are then necessary. The insect cell-baculovirus-based production technology has shown the ability to overcome these limitations. A recombinant trivalent hemagglutinin vaccine (RIV3 – Flublok®) produced using this system is available and licensed in the USA since 2013 for use in adults. This is the first vaccine to contain recombinant influenza virus proteins, with a hemagglutinin concentration that is three-times the one found in inactivated influenza vaccine. Different studies have shown that RIV3 is well tolerated, immunogenic and efficacious, thus proving it to be an additional option for immunization against influenza in adults.

Vaccination in patients with primary immune deficiency, secondary immune deficiency and autoimmunity with immune regulatory abnormalities

Vaccination has been an important healthcare measure in preventing infectious diseases. The response to vaccination is reduced in immunocompromised patients, primary immune deficiency (PID) and secondary immune deficiency (SID), but vaccination studies still demonstrated a protective effect resulting in reducing complications, hospitalization, treatment costs and even mortality. The primary physician and the specialist directing patient care are responsible for vaccination. Live vaccines are contraindicated in patients with severe immune impairment, killed vaccines are highly recommended in PID and SID. Criteria have been defined to distinguish high- or low-level immune impairment in the different disease entities among PID and SID patients. For patients who do not respond to diagnostic vaccination as characterized by antibody failure immunoglobulin replacement is the mainstay of therapy.