Flu and COVID-19 Vaccination: What Happens to the Flu Shot When the Campaigns Overlap? Experience from a Large Italian Research Hospital

Immunogenicity and protective efficacy of a co-formulated two-in-one inactivated whole virus particle COVID-19/influenza vaccine

Due to the synchronous circulation of seasonal influenza viruses and severe acute respiratory coronavirus 2 (SARS-CoV-2) which causes coronavirus disease 2019 (COVID-19), there is need for routine vaccination for both COVID-19 and influenza to reduce disease severity. Here, we prepared individual WPVs composed of formalin-inactivated SARS-CoV-2 WK 521 (Ancestral strain; Co WPV) or influenza virus [A/California/07/2009 (X-179A) (H1N1) pdm; Flu WPV] to produce a two-in-one Co/Flu WPV. Serum analysis from vaccinated mice revealed that a single dose of Co/Flu WPV induced antigen-specific neutralizing antibodies against both viruses, similar to those induced by either type of WPV alone. Following infection with either virus, mice vaccinated with Co/Flu WPV showed no weight loss, reduced pneumonia and viral titers in the lung, and lower gene expression of proinflammatory cytokines, as observed with individual WPV-vaccinated. Furthermore, a pentavalent vaccine (Co/qFlu WPV) comprising of Co WPV and quadrivalent influenza vaccine (qFlu WPV) was immunogenic and protected animals from severe COVID-19. These results suggest that a single dose of the two-in-one WPV provides efficient protection against SARS-CoV-2 and influenza virus infections with no evidence of vaccine interference in mice. We propose that concomitant vaccination with the two-in-one WPV can be useful for controlling both diseases.

COVID-19 Vaccination Coverage and Associated Factors in Patients with Multiple Sclerosis

Our objective was to know the COVID-19 vaccination coverage in multiple sclerosis (MS) patients and its factors associated. A retrospective cohort study was carried out. Patients seen at the MS unit of the University Clinical Hospital of Zaragoza between 2017 and 2021 were included. Variables were obtained by reviewing the specialized and primary care records. Associations between receiving COVID-19 full primo-vaccination, as well as one booster dose since autumn 2022, and the other variables were analyzed using bivariate analysis and multiple logistic regression models. Of the 359 included patients, 90.3% received the COVID-19 full primo-vaccination. Having been born in Spain (aOR = 3.40) and having received the 2020-2021 influenza vaccine (aOR = 6.77) were associated with receiving the COVID-19 full primo-vaccination. Vaccination with a COVID-19 booster dose was detected in 141 patients (39.3%). Sex (man) (aOR = 2.36), age (60 years or over) (aOR = 6.82), type of MS (Primary Progressive/Secondary Progressive) (aOR = 3.94), and having received the 2022-2023 influenza vaccine (aOR = 27.54) were associated with receiving such a booster dose. The COVID-19 booster dose was administered at the same time as the 2022-2023 influenza vaccine in 57.8% (67/116) of the patients vaccinated with both vaccines. The COVID-19 full primo-vaccination coverage is higher than in other countries. However, the decrease in vaccination coverage with the booster dose makes it necessary to develop strategies to improve it that are not limited to administering the flu vaccine together with the COVID-19 booster dose. Such strategies should be in focus, especially for women under 60 years of age.

Attitudes toward influenza vaccination in healthcare workers in Italy: A systematic review and meta-analysis

Healthcare workers (HCWs) are among the at-risk groups for whom influenza vaccination is strongly recommended. To assess the proportion of Italian HCWs with positive attitudes toward influenza vaccination, we conducted a systematic review of relevant literature and a meta-analysis. Our focus was on the influenza seasons from 2017/18 to 2021/22. The prevalence of favorable attitudes toward vaccination varied, ranging from 12% during the 2017/18 influenza season to 59% in the 2020/21 season. The significant increase in the 2020/21 season can be attributed to adaptations necessitated by the COVID-19 pandemic. During the 2021/22 influenza season, there was a decline in vaccination coverage (37%), likely due to the absence of a robust preventive culture. Various strategies have been employed to enhance HCWs' attitudes to achieve higher vaccination rates, but none of them have demonstrated satisfactory results. Policymakers should consider implementing a policy of mandatory vaccination to ensure elevated vaccination coverage among HCWs.

Co-administration of SARS-CoV-2 and influenza vaccines in healthcare workers: Results of two vaccination campaigns in a large teaching hospital in Rome

The concurrent administration of COVID-19 and influenza vaccines has arisen as a promising approach to bolster protection against respiratory pathogens and improve vaccination rates. However, there remains a lack of data regarding the prevalence of co-administration across several vaccination campaigns, especially among healthcare workers (HCWs). Therefore, this study aims to shed light on the acceptance of co-administration strategies among HCWs during the two campaigns following the introduction of the anti-SARS-CoV-2 vaccine. A retrospective cohort study was conducted among the HCWs of the Fondazione Policlinico Universitario "A. Gemelli" IRCCS, a research hospital in Rome. Hospital administrative databases were accessed to gather information about vaccination for SARS-CoV-2 and influenza during the 2021/2022 and 2022/2023 vaccination campaigns. The study included 7399 HCWs. The co-administration of anti-SARS-CoV-2 and influenza vaccines presented a significant rise in 2022/2023 compared to the previous vaccination campaign (+38%): this was confirmed for every professional category, with the largest increases among resident doctors (+47%) and physicians (+44%), and also for every age category, but it was particularly evident for the youngest health professionals. The probability of co-administration uptake during the 2022/2023 campaign was significantly higher for males, and for those that received co-administration during the 2021/2022 campaign, while the probability was lower for nurses and administrative staff. This study highlights the co-administration procedure as a valuable and effective tool in annual vaccination campaigns for SARS-CoV-2 and influenza. The procedure's safety and streamlined logistics make it increasingly attractive for implementation, particularly among HCWs.

Estimated Effectiveness of Coadministration of the BNT162b2 BA.4/5 COVID-19 Vaccine With Influenza Vaccine

Importance

No data comparing the estimated effectiveness of coadministering COVID-19 vaccines with seasonal influenza vaccine (SIV) in the community setting exist.

Objective

To examine the comparative effectiveness associated with coadministering the BNT162b2 BA.4/5 bivalent mRNA COVID-19 vaccine (BNT162b2-biv [Pfizer BioNTech]) and SIV vs giving each vaccine alone.

Design, Setting, and Participants

A retrospective comparative effectiveness study evaluated US adults aged 18 years or older enrolled in commercial health insurance or Medicare Advantage plans and vaccinated with BNT162b2-biv only, SIV only, or both on the same day between August 31, 2022, and January 30, 2023. Individuals with monovalent or another brand of mRNA bivalent COVID-19 vaccine were excluded.

Exposure

Same-day coadministration of BNT162b2-biv and SIV; receipt of BNT162b2-biv only (for COVID-19-related outcomes) or SIV only (for influenza-related outcomes) were the comparator groups. For adults aged 65 years or older, only enhanced SIVs were included.

Main Outcomes and Measures

COVID-19-related and influenza-related hospitalization, emergency department (ED) or urgent care (UC) encounters, and outpatient visits.

Results

Overall, 3 442 996 individuals (57.0% female; mean [SD] age, 65 [16.7] years) were included. A total of 627 735 individuals had BNT162b2-biv and SIV vaccine coadministered, 369 423 had BNT162b2-biv alone, and 2 445 838 had SIV alone. Among those aged 65 years or older (n = 2 210 493; mean [SD] age, 75 [6.7] years; 57.9% female), the coadministration group had a similar incidence of COVID-19-related hospitalization (adjusted hazard ratio [AHR], 1.04; 95% CI, 0.87-1.24) and slightly higher incidence of emergency department or urgent care encounters (AHR, 1.12; 95% CI, 1.02-1.23) and outpatient visits (AHR, 1.06; 95% CI, 1.01-1.11) compared with the BNT162b2-biv-only group. Among individuals aged 18 to 64 years (n = 1 232 503; mean [SD] age, 47 [13.1] years; 55.4% female), the incidence of COVID-19-related outcomes was slightly higher among those who received both vaccines vs BNT162b2-biv alone (AHR point estimate range, 1.14-1.57); however, fewer events overall in this age group resulted in wider CIs. Overall, compared with those who received SIV alone, the coadministration group had a slightly lower incidence of most influenza-related end points (AHR point estimates 0.83-0.93 for those aged ≥65 years vs 0.76-1.08 for those aged 18-64 years). Negative control outcomes suggested residual bias and calibration of COVID-19-related and influenza-related outcomes with negative controls moved all estimates closer to the null, with most CIs crossing 1.00.

Conclusions and Relevance

In this study, coadministration of BNT162b2-biv and SIV was associated with generally similar effectiveness in the community setting against COVID-19-related and SIV-related outcomes compared with giving each vaccine alone and may help improve uptake of both vaccines.

Increasing Influenza Vaccination Uptake by Sending Reminders: A Representative Cross-Sectional Study on the Preferences of Italian Adults

Evidence from countries that achieved a high seasonal influenza vaccination (SIV) coverage suggests that reminders to get vaccinated may increase SIV uptake. The goal of this study was to explore the experience and attitudes of Italian adults toward an active invitation to receive SIV, triggered by different sources and delivered via different communication channels, and to assess the projected benefits of this strategy. A cross-sectional survey on a representative sample of Italian adults was conducted by using computer-assisted web interviewing. Responses from 2513 subjects were analyzed. A total of 52.2% of individuals previously received invitations to undergo SIV and compared with people who did not receive any reminder were three times more likely (68.2% vs. 22.2%) to be vaccinated in the last season. Compared with other sources, reminders sent by general practitioners (GPs) were perceived as the most attractive. As for communication channels, most participants preferred text/instant messaging (24.6%) or email (27.2%), suggesting an acceleration in the Italian digital transformation triggered by the COVID-19 pandemic. Conversely, traditional postal letters or phone calls were preferred by only 17.0% and 8.6% of respondents, respectively. Reminders sent by GPs via text/instant messages or email are a valuable option for increasing SIV uptake among Italian adults.

Three-year COVID-19 and flu vaccinations among medical residents in a tertiary hospital in Italy: The threat of acceptance decline in seasonal campaigns

The COVID-19 vaccination campaign in Italy started in December 2020, and, due to the Omicron variant's emergence, a second booster dose was recommended for high-risk individuals and healthcare workers from July 2022. The aim of the study was to evaluate the vaccination coverages for the COVID-19 second booster dose and to identify predictors of its acceptance within the population of medical residents (MRs) of the Fondazione Policlinico Universitario "A. Gemelli" IRCCS (FPG) University Hospital. The study was conducted at FPG from October 4th to December 21st, 2022, and COVID-19 second booster dose and influenza vaccines were administered. The study analyzed collected data and conducted multivariate logistic regressions to explore potential predictors of vaccination adherence. The analyses performed were compared with the sample enrolled in FPG residency programs at the start of the COVID-19 vaccination campaign. 1968 MRs were involved in the 2022-2023 vaccination campaign (mean age 28.97, SD 3.44), and the second booster dose of COVID-19 vaccination coverage was low (18.80%). Almost all participants opted for co-administration of COVID-19 and influenza vaccinations, leading to a similar rate of influenza vaccination coverage (16.26%). Being a frontline resident, meaning a direct involvement in managing COVID-19 patients and vaccination campaigns, was the main predictor of vaccination adherence (OR 1.72, 95% CI 1.25-2.17). The dropping in influenza vaccination coverage in 2022-2023 and the low adherence to COVID-19 second booster dose among young physicians is concerning, calling for tailored vaccination campaigns and interventions.

Impact of COVID-19 pandemic on flu vaccine uptake in healthcare workers in Europe: a systematic review and meta-analysis

INTRODUCTION

Influenza immunization policies in Europe primarily target at-risk and vulnerable subjects. Healthcare workers (HCWs) are a key focus of vaccination campaigns. Our systematic review and meta-analysis aim to evaluate the role of the COVID-19 pandemic on influenza vaccine uptake among HCWs since the 2020/21 influenza season.

AREAS COVERED

Fourteen studies were included in the meta-analysis and systematic review, selected from scientific articles available in MEDLINE/PubMed, ISI Web of Knowledge, and Scopus databases between 1 January 2021 and 15 January 2023 The analysis revealed a significant relationship between influenza vaccine uptake and COVID-19 related determinants, such as willingness to receive COVID-19 vaccination, fear of COVID-19, and differentiating between influenza and COVID-19 symptoms (OR = 5.70; 95%CI = 2.08-15.60). Several studies reported higher vaccination coverages in the 2020/21 season compared to previous seasons, with VC values ranging from + 17% to + 38% compared to the 2019/20 season. The included studies identified a shift in HCWs' attitudes toward influenza vaccination, attributed to increased awareness due to the COVID-19 pandemic.

EXPERT OPINION

Vaccine hesitancy is common among HCWs in Europe, necessitating mutual strategies across all European countries. So far, mandatory vaccination policies have shown the most potential in achieving high and sustainable influenza vaccination rates among HCWs.

Combining Influenza and COVID-19 Booster Vaccination Strategy to Improve Vaccination Uptake Necessary for Managing the Health Pandemic: A Systematic Review and Meta-Analysis

Background: The uptake of COVID-19 booster vaccines has been significantly low. Therefore, it is questionable whether combining the COVID-19 booster vaccines with influenza vaccines can increase the population’s interest in taking such vaccines and manage the health pandemic effectively. Methodology: In this systematic review and meta-analysis, a synthesis of the findings and summary of a total of 30 research articles based on the topic, ‘combining influenza and COVID-19 booster vaccination strategy’ was undertaken. The research articles were identified from three databases, namely, PubMed, Cochran Library, and Google Scholar using specific keywords and inclusion criteria. However, research articles that were not peer-reviewed and not published in English were excluded from the systematic review and meta-analysis. The average risk ratio of the intervention group getting a combination of COVID-19 booster and influenza vaccines from the samples of the included studies was 0.78 with regard to a 95% CI. Such risk ratio is based on the null hypothesis of the current study that combining COVID-19 booster and influenza vaccines can increase the uptake of COVID-19 booster vaccines. On the other hand, the heterogeneity between such studies was I2 = 35%, while the statistical significance of their findings occurred at p < 0.05. The average p-value of the included research studies was p = 0.62 with the proportion of studies with significant p-values being 63.33% which is equivalent to 19 out of 30 studies. Therefore, the null hypothesis was not rejected in more than half of the studies. Results: A synthesis of the chosen research articles revealed that when influenza and COVID-19 booster vaccines are combined, there is potential for an increase in the uptake of the latter, mainly because many populations have already been accustomed to taking influenza vaccines on an annual basis. Conclusions: In this way, through such findings, medical health experts can make informed decisions to increase the population’s willingness to receive the COVID-19 booster vaccines.

Medical Residents' Behaviours toward Compulsory COVID-19 Vaccination in a Tertiary Hospital in Italy

To maintain safety conditions in the provision of care and assistance, and to protect healthcare workers (HCWs) and patients, the Italian government required compulsory COVID-19 vaccination for HCWs, including medical residents (MRs). The aim of this study was to assess COVID-19 vaccination coverage in MRs in a large tertiary hospital in Italy, before and after the introduction of compulsory vaccination, according to demographic characteristics and specific residency. A database on COVID-19 vaccination status and infection of resident medical doctors was created. Descriptive statistics and logistic regressions were carried out on the data. A total of 1894 MRs were included in the study. Being vaccinated in the same hospital as the residency program was significantly related to the year of residency and being enrolled in a frontline residency. A significant association between compliance with the compulsory primary cycle vaccination and vaccination in the hospital residency was observed. Being enrolled in the second, third, and last years of residency, and in a frontline residency, were predictive of being vaccinated in the residency hospital. Almost 100% of the MRs participating in the study were vaccinated against COVID-19. Compulsory vaccination of HCWs, alongside greater and clearer information about the risks and benefits of vaccination, represents an important booster to ensure public health and to promote quality and safety of care.

Declining influenza vaccination rates in an underserved pediatric primary care center during the COVID-19 pandemic

BACKGROUND

Influenza vaccination rates are decreasing in the United States. Disinformation surrounding COVID-related public health protections and SARS-CoV-2 vaccine roll-out may have unintended consequences impacting pediatric influenza vaccination.We assessed influenza vaccination rates before and during the COVID-19 pandemic in one pediatric primary care center, serving a minoritized population.

METHODS

A cross-sectional study assessed influenza vaccination rates for children aged 6 months to 12 years over the following influenza seasons (September-May): 1) 2018-19 and 2019-20 (pre-pandemic), and 2) 2020-21 and 2021-22 (intra-pandemic). Demographics and responses to social risk questionnaires were extracted from electronic health records. Total tetanus vaccinations across influenza seasons served as approximations of general vaccination rates. Generalized linear regression models with robust standard errors evaluated differences in demographics, social risks, and influenza vaccination rates by season. Multivariable logistic regression with robust standard errors evaluated associations between influenza season, demographics, social risks, and influenza vaccination.

RESULTS

Most patients were young (mean age ∼ 6 years), non-Hispanic Black (∼80%), and publicly insured (∼90%). Forty-two percent of patients eligible to receive the influenza vaccine who were seen in 2019-20 influenza season received the influenza vaccine, compared to 30% in 2021-22. Influenza and tetanus vaccination rates decreased during the COVID-19 pandemic (p < 0.01). The 2020-21 and 2021-22 influenza seasons, older age, Black race, and self-pay were associated with decreased influenza vaccine administration (p < 0.05).

CONCLUSIONS

Influenza vaccination rates within one pediatric primary care center decreased during the COVID-19 pandemic and have not rebounded, particularly for older children, those identifying as Black, and those without insurance.