The lifting of non-pharmaceutical measures preventing transmission of SARS-CoV-2 (and other viruses, including influenza viruses) raises concerns about healthcare resources and fears of an increased number of cases of influenza and COVID-19. For the 2021-2022 influenza season, the WHO and >20 European countries promoted coadministration of influenza and COVID-19 vaccines. Recently, the French Health Authority recommended coupling the COVID-19 vaccination with the 2022-2023 influenza vaccination campaign for healthcare professionals and people at risk of severe COVID-19. The present systematic review examines published data on the safety, immunogenicity, efficacy/effectiveness, and acceptability/acceptance of coadministration of influenza and COVID-19 vaccines. No safety concerns or immune interferences were found whatever the vaccines or the age of vaccinated subjects (65- or 65+). No efficacy/effectiveness data were available. The results should reassure vaccinees and vaccinators in case of coadministration and increase vaccine coverage. Healthcare systems promoting coupled campaigns must provide the necessary means for successful coadministration. The lifting of non-pharmaceutical measures recommended to prevent transmission of SARS-CoV-2 (and other viruses, including influenza viruses) raises concerns about healthcare resources, already under pressure. It also raises fears of an increase in the number of cases of influenza or COVID-19 infection during the winter season. For the 2021–2022 influenza season, the World Health Organization and several European countries promoted concomitant administration in distinct anatomic sites (i.e., coadministration) of influenza and COVID-19 vaccines to avoid additional stress on healthcare systems. In May 2022, the French Health Authority recommended coupling the COVID-19 vaccination with the 2022–2023 influenza vaccination campaign (i.e., starting COVID-19 vaccination at the date of influenza vaccination) for healthcare professionals and people at risk of severe COVID-19, in case of epidemic wave. Coadministration of influenza and COVID-19 vaccines is one of the factors of success for a coupled campaign. The present systematic review examines all published data (articles or reports, clinical trials, or surveys) on the safety, immunogenicity, efficacy/effectiveness, and acceptability/acceptance of coadministration of influenza and COVID-19 vaccines. The PRISMA method was used to collect information. No safety concerns or immune interferences were found whatever the vaccines or the age of vaccinated subjects (65- or 65+). No efficacy/effectiveness data were available. Acceptability and acceptance were good but could be improved. By reassuring vaccinees and vaccinators, these results are expected to favor coadministration and ultimately increase vaccine coverage, thus offering better protection. Healthcare systems promoting coupled campaigns with coadministration must provide the necessary means for their successful implementation.

Describing the characteristics of COVID-19 patients in the hospital is of importance to assist in the management of hospital capacity in the future. Here, we analyze the trajectories of 1321 patients admitted to hospitals in northern and eastern France. We found that the time from onset to hospitalization decreased with age, from 7.3 days in the 20–65 year-olds to 4.5 in the >80 year-olds (p < 0.0001). Overall, the length of stay in the hospital was 15.9 days, and the death rate was 20%. One patient out of four was admitted to the intensive care unit (ICU) for approximately one month. The characteristics of trajectories changed with age: fewer older patients were admitted to the ICU and the death rate was larger in the elderly. Admission shortly after onset was associated with increased mortality (odds-ratio (OR) = 1.8, Confidence Interval (CI) 95% [1.3, 2.6]) as well as male sex (OR = 2.1, CI 95% [1.5, 2.9]). Time from admission within the hospital to the transfer to ICU was short. The age- and sex-adjusted mortality rate decreased over the course of the epidemic, suggesting improvement in care over time. In the SARS-CoV-2 epidemic, the urgent need for ICU at admission and the prolonged length of stay in ICU are a challenge for bed management and organization of care.

Vaccination programs against COVID-19 are being scaled up. We aimed to assess the effects of vaccine characteristics on vaccine hesitancy among healthcare workers in a multi-center survey conducted within French healthcare facilities from 1 December 2020 to 26 March 2021. We invited any healthcare workers naïve of COVID-19 vaccination to complete an online self-questionnaire. They reported on their socio-demographic characteristics, as well as their perception and beliefs towards vaccination. We measured their willingness to get vaccinated in eight scenarios for candidates’ vaccines presented sequentially (1 to 4-point scale). Candidates’ vaccines varied for efficacy (25%, 50%, 100%), length of immunization (1 year or lifetime), frequency (<1/100, <1/10,000), and severity (none, moderate, severe) of adverse events. We analyzed 4349 healthcare workers’ responses with interpretable questionnaires. The crude willingness to get vaccinated was 53.2% and increased over time. We clustered the trajectories of responses using an unsupervised classification algorithm (k-means) and identified four groups of healthcare workers: those willing to get vaccinated in any scenario (18%), those not willing to get vaccinated at all (22%), and those hesitating but more likely to accept (32%) or reject (28%) the vaccination depending on the scenario. In these last two subgroups, vaccine acceptance was growing with age, educational background and was higher among men with condition. Compared to an ideal vaccine candidate, a 50% reduced efficacy resulted in an average drop in acceptance by 0.8 (SD ± 0.8, −23.5%), while it was ranging from 1.4 (SD ± 1.0, −38.4%) to 2.1 (SD ± 1.0, −58.4%) in case of severe but rare adverse event. The acceptance of a mandatory immunization program was 29.6% overall and was positively correlated to the willingness to get vaccinated, ranging from 2.4% to 60.0%. Even if healthcare workers represent a heterogeneous population, most (80%) could accept the vaccination against COVID-19. Their willingness to get the vaccine increased over time and as immunization programs became available. Among hesitant professionals, the fear of adverse events was the main concern. Targeted information campaigns reassuring about adverse events may increase vaccine coverage, in a population with a strong opinion about mandatory immunization programs.

Bronchopulmonary infections are a major trigger of cardiac decompensation and are frequently associated with hospitalizations in patients with heart failure (HF). Adverse cardiac effects associated with respiratory infections, more specifically Streptococcus pneumoniae and influenza infections, are the consequence of inflammatory processes and thrombotic events. For both influenza and pneumococcal vaccinations, large multicenter randomized clinical trials are needed to evaluate their efficacy in preventing cardiovascular events, especially in HF patients. No study to date has evaluated the protective effect of the COVID-19 vaccine in patients with HF. Different guidelines recommend annual influenza vaccination for patients with established cardiovascular disease and also recommend pneumococcal vaccination in patients with HF. The Heart Failure group of the French Society of Cardiology recently strongly recommended vaccination against COVID-19 in HF patients. Nevertheless, the implementation of vaccination recommendations against respiratory infections in HF patients remains suboptimal. This suggests that a national health policy is needed to improve vaccination coverage, involving not only the general practitioner, but also other health providers, such as cardiologists, nurses, and pharmacists. This review first summarizes the pathophysiology of the interrelationships between inflammation, infection, and HF. Then, we describe the current clinical knowledge concerning the protective effect of vaccines against respiratory diseases (influenza, pneumococcal infection, and COVID-19) in patients with HF and finally we propose how vaccination coverage could be improved in these patients.

Although effective mRNA vaccines for SARS-CoV-2 infection have been deployed worldwide, their interchangeability could facilitate the scale-up of vaccination programs. The objective of the trial was to assess whether the immune response induced by a heterologous SARS-CoV-2 mRNA primo vaccination is non-inferior to that of a homologous mRNA vaccination. We conducted a multicenter, randomized, open-label trial in adults 18 years of age and older who received a first dose of SARS-CoV-2 mRNA vaccine. Participants were randomly assigned in a 1:1 ratio to receive a second dose of BNT162b2 or mRNA-1273, 28 to 49 days after the first dose. Randomization was stratified on the vaccine received at the first vaccination. The primary endpoint was the anti-spike IgG antibodies titer measured 28 days after the second vaccine dose. This study is registered with ClinicalTrials.gov, Trial, NCT04900467. Of the 414 randomized participants recruited from May 28 to July 2, 2021, 390 were included in the per protocol analysis: 94 participants in group 1 (BNT162b2/BNT162b2), 96 in group 2 (BNT162b2/mRNA-1273), 97 in group 3 (mRNA-1273/mRNA-1273), and 103 in group 4 (mRNA-1273/BNT162b2). The geometric mean titers ratios of anti-spike IgG antibodies for each heterologous regimen relative to the corresponding homologous regimen were 1·37 (two-sided 95% CI, 1·10 to 1·72) in the groups 1 and 2 and 0·67 (two-sided 95% CI, 0·55 to 0·82) in the groups 3 and 4. Levels of neutralizing antibodies to the main circulating SARS-Cov-2 viral strains were higher with the vaccine regimen containing mRNA-1273. Participants who received mRNA-1273 as a second dose experienced a higher rate of local adverse reactions and general symptoms than those who received BNT162b2 (p < 0·0001). The two SARS-CoV-2 mRNA vaccines could be used with flexibility for the second dose of COVID-19 primo vaccination. Tolerance remains good regardless of vaccine sequence although mRNA-1273 was more reactogenic. French Ministries of Solidarity and Health and Research. BNT162b2 was provided by Pfizer/BioNTech. mRNA-1273 was provided by Moderna.

BACKGROUND: The high-dose quadrivalent influenza vaccine (QIV-HD) showed superior efficacy against laboratory-confirmed illness compared with the standard-dose quadrivalent influenza vaccine (QIV-SD) in randomized controlled trials with the elderly. However, specific underlying mechanism remains unclear. METHODS: This phase IV randomized controlled trial compared early innate responses induced by QIV-HD and QIV-SD in 59 individuals aged > 65 years. Systemic innate cells and gene signatures at day 0 (D0) and D1 as well as hemagglutinin inhibition antibody (HIA) titers at D0 and D21 after vaccination were assessed. RESULTS: QIV-HD elicited robust humoral response with significantly higher antibody titers and seroconversion rates than QIV-SD. At D1 after vaccination, QIV-HD recipients showed significant reduction in innate cells, including conventional DCs and NK cells, compared with QIV-SD, correlating with significantly increased HIA titers at D21. Blood transcriptomic analysis revealed greater amplitude of gene expression in the QIV-HD arm, encompassing genes related to innate immune response, IFNs, and antigen processing and presentation, and correlated with humoral responses. Interestingly, comparative analysis with a literature dataset from young adults vaccinated with influenza standard-dose vaccine highlighted strong similarities in gene expression patterns and biological pathways with the elderly vaccinated with QIV-HD. CONCLUSION: QIV-HD induces higher HIA titers than QIV-SD, a youthful boost of the innate gene expression significantly associated with high HIA titers. TRIAL REGISTRATION: EudraCT no. 2021-004573-32.