Association between influenza vaccination and one-year all-cause and cardiovascular mortality risk: A self-controlled case series and matched case-control study.

Debates surrounding the efficacy of influenza vaccination for survival benefits persist, and there is a lack of data regarding its duration of protection. A self-controlled case series (SCCS) and a 1:4 matched case-control study were conducted using the National Health Interview Survey (NHIS) and public-use mortality data from 2005 to 2018 in the United States. The SCCS study identified participants who received influenza vaccination within 12 months before the survey and subsequently died within 1 year of postvaccination. The matched case-control study paired participants who died during the influenza season at the time of survey with four survivors. Among 1167 participants in the SCCS study, there was a 46% reduction in all-cause mortality and a 43% reduction in cardiovascular mortality within 29-196 days of postvaccination. The greatest protection was observed during days 29-56 (all-cause mortality: RI: 0.19; 95% CI: 0.12-0.29; cardiovascular mortality: RI: 0.28; 95% CI: 0.14-0.56). Among 626 cases and 2504 controls included in the matched case-control study, influenza vaccination was associated with a reduction in all-cause mortality (OR: 0.74, 95% CI: 0.60-0.92) and cardiovascular mortality (OR: 0.64, 95% CI: 0.44-0.93) during the influenza season. This study highlights the importance of influenza vaccination in reducing the risks of all-cause and cardiovascular mortality, with effects lasting for approximately 6 months.

Phase 1, randomized, rater and participant blinded placebo-controlled study of the safety, reactogenicity, tolerability and immunogenicity of H1N1 influenza vaccine delivered by VX-103 (a MIMIX microneedle patch [MAP] system) in healthy adults.

BACKGROUND: The MIMIX platform is a novel microneedle array patch (MAP) characterized by slowly dissolving microneedle tips that deploy into the dermis following patch application. We describe safety, reactogenicity, tolerability and immunogenicity for MIMIX MAP vaccination against influenza. METHODOLOGY: The trial was a Phase 1, exploratory, first-in-human, parallel randomized, rater, participant, study analyst-blinded, placebo-controlled study in Canada. Forty-five healthy participants (18 to 39 years of age, inclusive) were randomized in a 1:1:1 ratio to receive either 15 µg or 7.5 µg of an H1N1 influenza vaccine, or placebo delivered via MIMIX MAP to the volar forearm. A statistician used a computer program to create a randomization scheme with a block size of 3. Post-treatment follow-up was approximately 180 days. Primary safety outcomes included the incidence of study product related serious adverse events and unsolicited events within 180 days, solicited application site and systemic reactogenicity through 7 days after administration and solicited application site erythema and/or pigmentation 14, 28, 56 and 180 days after administration. Immunogenicity outcomes included antibody titers and percentage of seroconversion (SCR) and seroprotection (SPR) rates determined by the hemagglutination inhibition (HAI) assay. Exploratory outcomes included virus microneutralization (MN) titers, durability and breadth of the immune response. The trial was registered with ClinicalTrials.gov, number NCT06125717. FINDINGS: Between July 7, 2022 and March 13, 2023 45 participants were randomized to a treatment group. One participant was lost to follow up in the 15 µg group and 1 participant withdrew from the 7.5 µg dose group. Safety analyses included n = 15 per group, immunogenicity analyses included n = 14 for the 15 µg and 7.5 µg treatment groups and n = 15 for the placebo group. No SAEs were reported in any of the treatment groups. All treatment groups reported solicited local events within 7 days after vaccination, with mild (Grade 1) erythema being the most frequent symptom reported. Other local symptoms reported included mostly mild (Grade 1) induration/swelling, itching, pigmentation, skin flaking, and tenderness. Within 7 days after vaccination, 2 participants (4.4%) reported moderate (Grade 2) erythema, 1 participant (2.2%) reported moderate (Grade 2) induration/swelling, and 1 participant (2.2%) reported moderate (Grade 2) itching. There was an overall reduction in erythema and pigmentation reported on Days 15, 29, 57, and 180 among all treatment groups. Systemic symptoms reported within 7 days after vaccination, included mild (Grade 1) fatigue reported among all treatment groups, and mild (Grade 1) headache reported by 1 participant in the 7.5 µg treatment group. No study drug related severe symptoms were reported in the study. Group mean fold rises in HAI titers ranged between 8.7 and 12-fold, SCRs were >76% and SPRs were >92% for both VX-103 dose groups thereby fulfilling serological criteria established by the EMA and FDA for seasonal influenza vaccines. Longitudinal assessments demonstrate persistence of the immune response through at least Day 180. CONCLUSIONS: The MIMIX MAP platform is safe, well tolerated and elicits robust antibody responses.

Trends in the administration of COVID-19 vaccines with other vaccines in the United States reported to V-safe during December 14, 2020-May 19, 2023.

Introduction COVID-19 vaccines may be administered with other vaccines during the same healthcare visit. COVID-19 monovalent (Fall 2021) and bivalent (Fall 2022) vaccine recommendations coincided with annual seasonal influenza vaccination. Data describing the frequency of the co-administration of COVID-19 vaccines with other vaccines are limited. Methods We used V-safe, a voluntary smartphone-based U.S. safety surveillance system established by the CDC, to describe trends in the administration of COVID-19 vaccines with other vaccines reported to V-safe during December 14, 2020 - May 19, 2023. Results Of the 21 million COVID-19 vaccinations reported to V-safe, 2.2% (459,817) were administered with at least 1 other vaccine. Co-administration most frequently occurred during the first week of October 2023 (27,092; 44.1%). Most reports of co-administration included influenza vaccine (393,003; 85.5%). Co-administration was most frequently reported for registrants aged 6 months-6 years (4,872; 4.4%). Conclusion Reports of co-administration to V-safe peaked during October 2023, when influenza vaccination most often occurs, possibly reflecting increased opportunities for multiple vaccinations and greater acceptability of the co-administration of COVID-19 vaccine with other vaccines, especially influenza vaccine.

Predictors of parental acceptance to live attenuated influenza vaccine for children.

To determine the influencing factors of Chinese parents' intention and behavior for children to receive live attenuated influenza vaccine during the 2022-2023 influenza season. A theoretical model was developed and included seven constructs, and structural equation modeling was used to test 11 hypotheses. From October 2022 to December 2023, a survey was conducted across 38 medical institutions in four Chinese cities and their subordinate districts, counties, and rural areas. Parents who accompanied their children for vaccinations were selected through a randomization process based on their child's medical card numbers. Measures were taken to minimize method bias, including a diverse geographical representation and random sampling. The survey resulted in the collection of 936 valid responses, exceeding the recommended sample size for structural equation model analysis and providing robust statistical inferences. During the study period, 936 respondents were included in the study. Perceived ease of use was verified to be a predictor of perceived usefulness and perceived value. Perceived usefulness was verified as a predictor of perceived value and behavioral intention. Knowledge was a significant antecedent of perceived value and risk perception of influenza disease. Risk perception of influenza disease was proved to be a significant predictor of perceived value and self-reported vaccination behavior. Perceived value significantly affected behavioral intention, and behavioral intention significantly affected self-reported vaccination behavior. Six demographic variables significantly moderate the theoretical models. The low vaccination coverage of live attenuated influenza vaccine (LAIV) among children in China suggests a need for a deeper understanding of the factors that influence vaccination rates. Particularly, effective strategies are necessary from policymakers and practitioners to elevate childhood LAIV coverage.

The economic rationale for cell-based influenza vaccines in children and adults: A review of cost-effectiveness analyses.

Seasonal influenza significantly affects both health and economic costs in children and adults. This narrative review summarizes published cost-effectiveness analyses (CEAs) of cell-based influenza vaccines in children and adults <65 years of age, critically assesses the assumptions and approaches used in these analyses, and considers the role of cell-based influenza vaccines for children and adults. CEAs from multiple countries demonstrated the cost-effectiveness of cell-based quadrivalent influenza vaccines (QIVc) compared with egg-based trivalent/quadrivalent influenza vaccines (TIVe/QIVe). CEA findings were consistent across models relying on different relative vaccine effectiveness (rVE) estimate inputs, with the rVE of QIVc versus QIVe ranging from 8.1% to 36.2% in favor of QIVc. Across multiple scenarios and types of analyses, QIVc was consistently cost-effective compared with QIVe, including in children and adults across different regions of the world.

Medical and dental student knowledge about COVID-19 and influenza vaccines impact opinions about vaccine advocacy and future practice.

Introduction: The World Health Organization has identified vaccine hesitancy as a global public health challenge. Healthcare providers are among the most influential and trusted figures for vaccine counseling. This article focuses on COVID-19 and influenza personal immunization behaviors, vaccine knowledge and opinions, and vaccine counseling confidence among future healthcare providers - dental and medical students. Methods: A cross-sectional anonymous online survey was conducted at four dental schools and one allopathic medical school in the United States. Items included personal vaccination status for the COVID-19 and influenza vaccines and vaccine-specific items developed based on past research to assess knowledge, opinions, and behaviors. Results: Two hundred and thirty-two medical and 221 dental students completed the survey. 68 and 55% scored average/above-average knowledge on COVID-19 and influenza vaccine items, respectively. There were significant differences between those with average/above-average and below-average knowledge scores regarding learning about, recommending, and advocating for vaccines and counseling vaccine-hesitant patients for both vaccines (p < 0.0001). Although higher-knowledge students had higher vaccination rates (p < 0.0001), many had insufficient knowledge about vaccines. Discussion: Healthcare providers play a crucial role in vaccine advocacy. The identified knowledge gaps are significant as they impact quality of patient care. And opinions about future vaccination practice such as recommending, providing, and counseling about vaccines. Equipping students with knowledge and communication skills will enable them to be strong vaccine advocates to improve overall public health.

SARS-CoV-2 and influenza vaccine hesitancy during the COVID-19 pandemic in a dynamic perspective.

To investigate the dynamic evolution of vaccine hesitancy toward both COVID-19 and influenza in a context characterized by the compresence of SARS-CoV-2 pandemic and seasonal flu epidemics, a two times repeated cross-sectional exploratory design was performed at Udine Hospital (Italy) following a cohort of 479 adult patients with a previous history of SARS-CoV-2 infection in 2020. Vaccine attitude was assessed through standardized telephone interviews performed at 12 and 18 months after the acute illness. The first interview reported the success of the 2020/21 seasonal influenza immunization with 46.8% (224/479) of the participants showing a positive attitude, especially the elderly and people with comorbidities (p < .001), but the investigation conducted at 18 months showed a drastic drop in flu shot acceptance (30/166, 18.1%). On the other hand, a great increase in vaccinations against SARS-CoV-2 occurred after the introduction of Green Pass (26.7% vs 72.9%). The major drivers of flu vaccine skepticism were represented by the feeling of protection regardless of prevention and by concerns regarding vaccines safety and efficacy; conversely compulsory strategies seemed to play a secondary role, since only a minority of the participants identified in the restrictions induced by the certification the major incentive to get immunized against SARS-CoV-2. The focus on this peculiar historical period helps to take a step forward in the comprehension of the complexity and dynamicity of the vaccine hesitancy phenomenon. Future vaccination campaigns will need to consider the role of personal opinions and emotions, interpreted according to the social and political context.

Inactivated influenza virus vaccines expressing COBRA hemagglutinin elicited broadly reactive, long-lived protective antibodies.

The influenza viruses cause seasonal respiratory illness that affect millions of people globally every year. Prophylactic vaccines are the recommended method to prevent the breakout of influenza epidemics. One of the current commercial influenza vaccines consists of inactivated viruses that are selected months prior to the start of a new influenza season. In many seasons, the vaccine effectiveness (VE) of these vaccines can be relatively low. Therefore, there is an urgent need to develop an improved, more universal influenza vaccine (UIV) that can provide broad protection against various drifted strains in all age groups. To meet this need, the computationally optimized broadly reactive antigen (COBRA) methodology was developed to design a hemagglutinin (HA) molecule as a new influenza vaccine. In this study, COBRA HA-based inactivated influenza viruses (IIV) expressing the COBRA HA from H1 or H3 influenza viruses were developed and characterized for the elicitation of immediate and long-term protective immunity in both immunologically naïve or influenza pre-immune animal models. These results were compared to animals vaccinated with IIV vaccines expressing wild-type H1 or H3 HA proteins (WT-IIV). The COBRA-IIV elicited long-lasting broadly reactive antibodies that had hemagglutination-inhibition (HAI) activity against drifted influenza variants.

Epidemic patterns of the different influenza virus types and subtypes/lineages for 10 years in Chongqing, China, 2010-2019.

To optimize seasonal influenza control and prevention programs in regions with potentially complicated seasonal patterns. Descriptive epidemiology was used to analyze the etiology of influenza, and chi-square tests were used to compare the epidemic patterns among different influenza virus types and subtypes/lineages. From January 2010 to December 2019, a total of 63,626 ILI cases were reported in Chongqing and 14,136 (22.22%) were laboratory-confirmed influenza cases. The proportions of specimens positive for influenza A and influenza B were 13.32% (8,478/63,626) and 8.86% (5,639/63,626), respectively. The proportion of positive specimens for influenza A reached the highest in winter (23.33%), while the proportion of positive specimens for influenza B reached the highest in spring (11.88%). Children aged 5-14 years old had the highest proportion of positive specimens for influenza. The influenza virus types/subtypes positive was significantly different by seasons and age groups (P<.001), but not by gender (p = .436). The vaccine strains were matched to the circulating influenza virus strains in all other years except for 2018 (vaccine strain was B/Colorado/06/2017; circulating strain was B/Yamagata). The study showed significant variations in epidemic patterns, including seasonal epidemic period and age distributions, among different influenza types, subtypes/lineages in Chongqing. Influenza vaccines matched to the circulating influenza virus strain in nine of the ten years. To prevent and mitigate the influenza outbreaks in this area, high risk population, especially children aged 5-14 years, are encouraged to get vaccinated against influenza before the epidemic seasons.

Association between combination COVID-19-influenza vaccination and long COVID in middle-aged and older Europeans: A cross-sectional study.

The potential impact of combined COVID-19 and influenza vaccination on long COVID remains uncertain. In the present cross-sectional study, we aimed to investigate the plausible association between them in middle-aged and older Europeans based on the Survey of Health, Ageing, and Retirement in Europe (SHARE). A total of 1910 participants were recruited in the analyses. The study outcome was long COVID. Participants were divided into 4 groups through the self-reported status of COVID-19 and influenza vaccination. Odds ratios (ORs) and 95% confidence intervals (CIs) were estimated. 1397 participants experienced long COVID. After multivariable adjustment, those vaccinated with neither COVID-19 nor influenza vaccine had higher risk of long COVID (OR, 1.72; 95% CI, 1.26-2.35) compared to those vaccinated with both vaccines. Furthermore, adding the 4 statuses of COVID-19 vaccination/influenza vaccination to conventional risk model improved risk reclassification for long COVID (continuous net reclassification improvement was 16.26% [p = .003], and integrated discrimination improvement was 0.51% [p = .005]). No heterogeneity was found in the subgroup analyses (all p-interaction ≥0.05). Our study might provide a strategy for people aged 50 and over to reduce the occurrence of long COVID, that is, to combine the use of the COVID-19 vaccine and influenza vaccines.

Effectiveness of inactivated influenza vaccine against laboratory-confirmed influenza among Chinese elderly: a test-negative design.

BACKGROUND: Evidence on the effectiveness of influenza vaccination in the elderly is limited, and results are controversial. There are also few reports from China. METHODS: We conducted a test-negative case-control study design to estimate influenza vaccine effectiveness (VE) against laboratory-confirmed influenza-associated visits among elderly (aged ≥ 60 years) across four influenza seasons in Ningbo, China, from 2018 to 19 to 2021-22. Influenza-positive cases and negative controls were randomly matched in a 1:1 ratio according to age, sex, hospital, and date of influenza testing. We used logistic regression models to compare vaccination odds ratios (ORs) in cases to controls. We calculated the VE as [100% × (1-adjusted OR)] and calculated the 95% confidence interval (CI) around the estimate. RESULTS: A total of 30,630 elderly patients tested for influenza with virus nucleic acid or antigen during the study period. After exclusions, we included 1 825 influenza-positive cases and 1 825 influenza-negative controls. Overall, the adjusted VE for influenza-related visits was 63.5% (95% CI, 56.3-69.5%), but varied by season. Influenza VE was 59.8% (95% CI, 51.5-66.7%) for influenza A and 89.6% (95% CI, 77.1-95.3%) for influenza B. The VE for ages 60-69 and 70-79 was 65.2% (95% CI, 55.4-72.9%) and 69.8% (95% CI, 58.7-77.9%), respectively, but only 45.4% (95% CI, 6.2-68.2%) for ages 80 and over. CONCLUSIONS: Standard-dose inactivated influenza vaccine has shown good protection in the elderly in China. However, protection may not be satisfactory in people aged 80 years and older.

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

BACKGROUND: Seasonal influenza epidemics have a substantial public health and economic burden, which can be alleviated through vaccination. The World Health Organization (WHO) recommends a 75% vaccination coverage rate (VCR) in: older adults (aged ≥ 65 years), individuals with chronic conditions, pregnant women, children aged 6-24 months and healthcare workers. However, no European country achieves this target in all risk groups. In this study, potential public health and economic benefits achieved by reaching 75% influenza VCR was estimated in risk groups across four European countries: France, Italy, Spain, and the UK. METHODS: A static epidemiological model was used to estimate the averted public health and economic burden of increasing the 2021/2022 season VCR to 75%, using the efficacy data of standard-dose quadrivalent influenza vaccine. For each country and risk group, the most recent data on population size, VCR, pre-pandemic influenza epidemiology, direct medical costs and absenteeism were identified through a systematic literature review, supplemented by manual searching. Outcomes were: averted influenza cases, general practitioner (GP) visits, hospitalisations, case fatalities, number of days of work lost, direct medical costs and absenteeism-related costs. RESULTS: As of the 2021/2022 season, the UK achieved the highest weighted VCR across risk groups (65%), followed by Spain (47%), France (44%) and Italy (44%). Based on modelling, the 2021/2022 VCR prevented an estimated 1.9 million influenza cases, avoiding 375,200 GP visits, 73,200 hospitalisations and 38,400 deaths. To achieve the WHO 75% VCR target, an additional 24 million at-risk individuals would need to be vaccinated, most of which being older adults and patients with chronic conditions. It was estimated that this could avoid a further 918,200 influenza cases, 332,000 GP visits, 16,300 hospitalisations and 6,300 deaths across the four countries, with older adults accounting for 52% of hospitalisations and 80% of deaths. An additional €84 million in direct medical costs and €79 million in absenteeism costs would be saved in total, with most economic benefits delivered in France. CONCLUSIONS: Older adults represent most vaccine-preventable influenza cases and deaths, followed by individuals with chronic conditions. Health authorities should prioritise vaccinating these populations for maximum public health and economic benefits.

A Profile of Influenza Vaccine Coverage for 2019-2020: Database Study of the English Primary Care Sentinel Cohort.

BACKGROUND: Innovation in seasonal influenza vaccine development has resulted in a wider range of formulations becoming available. Understanding vaccine coverage across populations including the timing of administration is important when evaluating vaccine benefits and risks. OBJECTIVE: This study aims to report the representativeness, uptake of influenza vaccines, different formulations of influenza vaccines, and timing of administration within the English Primary Care Sentinel Cohort (PCSC). METHODS: We used the PCSC of the Oxford-Royal College of General Practitioners Research and Surveillance Centre. We included patients of all ages registered with PCSC member general practices, reporting influenza vaccine coverage between September 1, 2019, and January 29, 2020. We identified influenza vaccination recipients and characterized them by age, clinical risk groups, and vaccine type. We reported the date of influenza vaccination within the PCSC by International Standard Organization (ISO) week. The representativeness of the PCSC population was compared with population data provided by the Office for National Statistics. PCSC influenza vaccine coverage was compared with published UK Health Security Agency's national data. We used paired t tests to compare populations, reported with 95% CI. RESULTS: The PCSC comprised 7,010,627 people from 693 general practices. The study population included a greater proportion of people aged 18-49 years (2,982,390/7,010,627, 42.5%; 95% CI 42.5%-42.6%) compared with the Office for National Statistics 2019 midyear population estimates (23,219,730/56,286,961, 41.3%; 95% CI 4.12%-41.3%; P<.001). People who are more deprived were underrepresented and those in the least deprived quintile were overrepresented. Within the study population, 24.7% (1,731,062/7,010,627; 95% CI 24.7%-24.7%) of people of all ages received an influenza vaccine compared with 24.2% (14,468,665/59,764,928; 95% CI 24.2%-24.2%; P<.001) in national data. The highest coverage was in people aged ≥65 years (913,695/1,264,700, 72.3%; 95% CI 72.2%-72.3%). The proportion of people in risk groups who received an influenza vaccine was also higher; for example, 69.8% (284,280/407,228; 95% CI 69.7%-70%) of people with diabetes in the PCSC received an influenza vaccine compared with 61.2% (983,727/1,607,996; 95% CI 61.1%-61.3%; P<.001) in national data. In the PCSC, vaccine type and brand information were available for 71.8% (358,365/498,923; 95% CI 71.7%-72%) of people aged 16-64 years and 81.9% (748,312/913,695; 95% CI 81.8%-82%) of people aged ≥65 years, compared with 23.6% (696,880/2,900,000) and 17.8% (1,385,888/7,700,000), respectively, of the same age groups in national data. Vaccination commenced during ISO week 35, continued until ISO week 3, and peaked during ISO week 41. The in-week peak in vaccination administration was on Saturdays. CONCLUSIONS: The PCSC's sociodemographic profile was similar to the national population and captured more data about risk groups, vaccine brands, and batches. This may reflect higher data quality. Its capabilities included reporting precise dates of administration. The PCSC is suitable for undertaking studies of influenza vaccine coverage.

Assessing the determinants of influenza and COVID-19 vaccine co-administration decisions in the elderly.

This research examines the low rate of co-administration of influenza and COVID-19 vaccines among seniors aged 65 and older in Korea, despite recommendations from authorities and academia worldwide. The study aimed to understand the influence of general characteristics and health beliefs on the vaccination choices of seniors, who were categorized into four groups based on their vaccination status: influenza only, COVID-19 only, both, or neither. A total of 400 participants, aged 65 and above, were selected through proportional stratified random sampling from five major Korean regions for a survey conducted between November 24th and December 15th, 2023. The results indicated no significant differences in general characteristics across these groups. However, regarding the health beliefs showed significant differences in perceived susceptibility and self-efficacy between the influenza-only and co-administration groups. Higher levels of perceived susceptibility and self-efficacy were associated with choosing co-administration. Contrary to previous studies focusing on safety concerns as a primary factor in vaccine hesitancy, this study highlights the role of individual health-related beliefs, particularly perceived susceptibility and self-efficacy, as critical in influencing the decision for co-administration among the elderly in Korea.

The effect of oral probiotics on response to vaccination in older adults: a systematic review of randomised controlled trials.

This systematic review evaluated the impact of oral probiotics on the immune response to vaccination in older people. A literature search was performed in three electronic databases up to January 2023. Randomised controlled trials (RCTs) conducted in older people (age ≥ 60 years) investigating oral probiotics and vaccine response outcomes were included. Characteristics and outcome data of the included studies were extracted and analysed and study quality was assessed using the Cochrane Risk of Bias Tool for randomised trials. Ten RCTs involving 1,560 participants, reported in 9 papers, were included. Nine studies involved the seasonal influenza vaccine and one a COVID-19 vaccine. All studies used lactobacilli, some in combination with bifidobacteria. Studies reported outcomes including anti-vaccine antibody titres or concentrations, seroconversion and seroprotection. When comparing antibody titres, seroprotection rate and seroconversion rate between probiotic and placebo groups expressed as a response ratio, the weighted mean values were 1.29, 1.16 and 2.00, respectively. Meta-analysis showed that probiotics increase seroconversion rates to all three strains of the seasonal influenza vaccine: odds ratio (95% confidence interval) 2.74 (1.31, 5.70; P = 0.007) for the H1N1 strain; 1.90 (1.04, 3.44; P = 0.04) for the H3N2 strain; 1.72 (1.05, 2.80; P = 0.03) for the B strain. There was a low level of heterogeneity in these findings. Several studies were at high risk of bias due to missing outcome data. Lactobacilli may improve the vaccine response, but further research is needed to be more certain of this.

Determinants of uptake of influenza, zoster and pneumococcal vaccines in patients with cardiovascular diseases.

BACKGROUND: Globally, cardiovascular disease (CVD) is the leading cause of death and illness. Vaccine-preventable infections may increase acute coronary vascular disease events and the risk of complications. Low vaccine coverage has been reported among adults at high risk of complications from vaccine-preventable infections. There is a gap in research evidence around determinants of uptake of vaccines among adults with CVD. This study examined the uptake of influenza, pneumococcal and zoster vaccines and the determinants of uptake of the vaccines among cardiac patients. METHOD: A prospective cross-sectional study was carried out among hospitalised cardiac patients through an interviewer-administered questionnaire. Descriptive statistics were used to investigate self-reported uptake of influenza, pneumococcal and zoster vaccines. Univariate and multivariate analyses of participants' social demographic and clinical characteristics were conducted to identify factors for receiving influenza vaccine. RESULTS: Low vaccination rates among 104 participants were found for influenza (45.2%), pneumococcal (13.5%) and zoster (5.8%) vaccines. The most common reason for not receiving influenza vaccine was concern about side effects. Lack of awareness about the pneumococcal and zoster vaccines was the main reason for the poor uptake of these vaccines. Australia-born participants were more likely to receive influenza vaccine than overseas-born participants. Working-age participants and, interestingly, people living with a current smoker were less likely to receive influenza vaccine. CONCLUSION: Influenza, pneumococcal and zoster vaccine uptake among cardiac patients was low. Encouraging physician recommendations for vaccination for cardiac patients under 65 years of age and addressing vaccination challenges among people from culturally and linguistically diverse backgrounds and pharmacy, workplace, and hospital vaccination may help increase vaccination uptake among cardiac patients.

Assessment of potential adverse events following the 2022-2023 seasonal influenza vaccines among U.S. adults aged 65 years and older.

BACKGROUND: While safety of influenza vaccines is well-established, some studies have suggested potential associations between influenza vaccines and certain adverse events (AEs). This study examined the safety of the 2022-2023 influenza vaccines among U.S. adults ≥ 65 years. METHODS: A self-controlled case series compared incidence rates of anaphylaxis, encephalitis/encephalomyelitis, Guillain-Barré Syndrome (GBS), and transverse myelitis following 2022-2023 seasonal influenza vaccinations (i.e., any, high-dose or adjuvanted) in risk and control intervals among Medicare beneficiaries ≥ 65 years. We used conditional Poisson regression to estimate incidence rate ratios (IRRs) and 95 % confidence intervals (CIs) adjusted for event-dependent observation time and seasonality. Analyses also accounted for uncertainty from outcome misclassification where feasible. For AEs with any statistically significant associations, we stratified results by concomitant vaccination status. RESULTS: Among 12.7 million vaccine recipients, we observed 76 anaphylaxis, 276 encephalitis/encephalomyelitis, 134 GBS and 75 transverse myelitis cases. Only rates of anaphylaxis were elevated in risk compared to control intervals. With all adjustments, an elevated, but non-statistically significant, anaphylaxis rate was observed following any (IRR: 2.40, 95% CI: 0.96-6.03), high-dose (IRR: 2.31, 95% CI: 0.67-7.91), and adjuvanted (IRR: 3.28, 95% CI: 0.71-15.08) influenza vaccination; anaphylaxis IRRs were 2.54 (95% CI: 0.49-13.05) and 1.64 (95% CI: 0.38-7.05) for persons with and without concomitant vaccination, respectively. CONCLUSIONS: Rates of encephalitis/encephalomyelitis, GBS, or transverse myelitis were not elevated following 2022-2023 seasonal influenza vaccinations among U.S. adults ≥ 65 years. There was an increased rate of anaphylaxis following influenza vaccination that may have been influenced by concomitant vaccination.

Lipid nanoparticle composition for adjuvant formulation modulates disease after influenza virus infection in quadrivalent influenza vaccine vaccinated mice.

There are considerable avenues through which currently licensed influenza vaccines could be optimized. We tested influenza vaccination in a mouse model with two adjuvants: Sendai virus-derived defective interfering (SDI) RNA, a RIG-I agonist; and an amphiphilic imidazoquinoline (IMDQ-PEG-Chol), a TLR7/8 agonist. The negatively charged SDI RNA was formulated into lipid nanoparticles (LNPs) facilitating direct delivery of SDI RNA to the cytosol, where RIG-I sensing induces inflammatory and type I interferon responses. We previously tested SDI RNA and IMDQ-PEG-Chol as standalone and combination adjuvants for influenza and SARS-CoV-2 vaccines. Here, we tested two different ionizable lipids, K-Ac7-Dsa and S-Ac7-Dog, for LNP formulations. The LNPs were incorporated with SDI RNA to determine its potential as a combination adjuvant with IMDQ-PEG-Chol by evaluating the host immune response to vaccination and infection in immunized BALB/c mice. Adjuvanticity of IMDQ-PEG-Chol with and without empty or SDI-loaded LNPs was validated with quadrivalent inactivated influenza vaccine (QIV), showing robust induction of antibody titers and T-cell responses. Depending on the adjuvant combination and LNP formulation, humoral and cellular vaccine responses could be tailored towards type 1 or type 2 host responses with specific cytokine profiles that correlated with the protective responses to viral infection. The extent of protection conferred by different vaccine/LNP/adjuvant combinations was tested by challenging mice with a vaccine-matched strain of influenza A virus A/Singapore/gp1908/2015 IVR-180 (H1N1). Groups that received either LNP formulated with SDI or IMDQ-PEG-Chol, or both, showed very low levels of viral replication in their lungs at 5 days post-infection (DPI). These studies provide evidence that the combination of vaccines with LNPs and/or adjuvants promote antigen-specific cellular responses that can contribute to protection upon infection. Interestingly, we observed differences in humoral and cellular responses to vaccination between different groups receiving K-Ac7-Dsa or S-Ac7-Dog lipids in LNP formulations. The differences were also reflected in inflammatory responses in lungs of vaccinated animals to infection, depending on LNP formulations. Therefore, this study suggests that the composition of the LNPs, particularly the ionizable lipid, plays an important role in inducing inflammatory responses in vivo, which is important for vaccine safety and to prevent adverse effects upon viral exposure.

End of 2022/23 Season Influenza Vaccine Effectiveness in Primary Care in Great Britain.

BACKGROUND: The 2022/23 influenza season in the United Kingdom saw the return of influenza to prepandemic levels following two seasons with low influenza activity. The early season was dominated by A(H3N2), with cocirculation of A(H1N1), reaching a peak late December 2022, while influenza B circulated at low levels during the latter part of the season. From September to March 2022/23, influenza vaccines were offered, free of charge, to all aged 2-13 (and 14-15 in Scotland and Wales), adults up to 49 years of age with clinical risk conditions and adults aged 50 and above across the mainland United Kingdom. METHODS: End-of-season adjusted vaccine effectiveness (VE) estimates against sentinel primary-care attendance for influenza-like illness, where influenza infection was laboratory confirmed, were calculated using the test negative design, adjusting for potential confounders. METHODS: Results In the mainland United Kingdom, end-of-season VE against all laboratory-confirmed influenza for all those > 65 years of age, most of whom received adjuvanted quadrivalent vaccines, was 30% (95% CI: -6% to 54%). VE for those aged 18-64, who largely received cell-based vaccines, was 47% (95% CI: 37%-56%). Overall VE for 2-17 year olds, predominantly receiving live attenuated vaccines, was 66% (95% CI: 53%-76%). CONCLUSION: The paper provides evidence of moderate influenza VE in 2022/23.

Interim 2023/2024 Season Influenza Vaccine Effectiveness in Primary and Secondary Care in the United Kingdom.

BACKGROUND: We report 2023/2024 season interim influenza vaccine effectiveness for three studies, namely, primary care in Great Britain, hospital settings in Scotland and hospital settings in England. METHODS: A test negative design was used to estimate vaccine effectiveness. RESULTS: Estimated vaccine effectiveness against all influenzas ranged from 63% (95% confidence interval 46 to 75%) to 65% (41 to 79%) among children aged 2-17, from 36% (20 to 49%) to 55% (43 to 65%) among adults 18-64 and from 40% (29 to 50%) to 55% (32 to 70%) among adults aged 65 and over. CONCLUSIONS: During a period of co-circulation of influenza A(H1N1)pdm09 and A(H3N2) in the United Kingdom, evidence for effectiveness of the influenza vaccine in both children and adults was found.