Thrombocytopenia including immune thrombocytopenia after receipt of mRNA COVID-19 vaccines reported to the Vaccine Adverse Event Reporting System (VAERS)

BackgroundThe objective of this study is to assess cases of thrombocytopenia, including immune thrombocytopenia (ITP), reported to the Vaccine Adverse Event Reporting System (VAERS) following vaccination with mRNA COVID-19 vaccines.MethodsThis case-series study analyzed VAERS reports of thrombocytopenia after vaccination with Pfizer-BioNTech COVID-19 Vaccine or Moderna COVID-19 Vaccine.ResultsFifteen cases of thrombocytopenia were identified among 18,841,309 doses of Pfizer-BioNTech COVID-19 Vaccine and 13 cases among 16,260,102 doses of Moderna COVID-19 Vaccine. The reporting rate of thrombocytopenia was 0.80 per million doses for both vaccines. Based on an annual incidence rate of 3.3 ITP cases per 100,000 adults, the observed number of all thrombocytopenia cases, which includes ITP, following administration of mRNA COVID-19 vaccines is not greater than the number of ITP cases expected.ConclusionsThe number of thrombocytopenia cases reported to VAERS does not suggest a safety concern attributable to mRNA COVID-19 vaccines at this time.     

SIRVA (Shoulder Injury Related to Vaccine Administration) following mRNA COVID-19 Vaccination: Case discussion and literature review

Shoulder injury related to vaccine administration (SIRVA) is an increasingly recognised complication after vaccination and presents with significant shoulder pain and stiffness. SIRVA is thought to occur as a result of improper administration of vaccine into the subdeltoid bursa or shoulder joint. This results in an inflammatory cascade that damages the structures in the shoulder region. The incidence of SIRVA is relatively higher for influenza vaccination due its widespread administration. We present a reported case of SIRVA following a mRNA COVID-19 vaccination and review the current literature. As we embark on a worldwide scale of COVID-19 vaccination, it is of utmost important that we use proper vaccination techniques and screen patients at risk of SIRVA. This would improve the efficacy of the vaccine and improve the outcomes of the vaccination programme.     

Safety of co-administration of mRNA COVID-19 and seasonal inactivated influenza vaccines in the vaccine adverse event reporting system (VAERS) during July 1, 2021–June 30, 2022

BackgroundCOVID-19 vaccines may be co-administered with other recommended vaccines, including seasonal influenza vaccines. However, few studies have evaluated the safety of co-administration of mRNA COVID-19 and seasonal influenza vaccines.ObjectiveTo describe reports to the Vaccine Adverse Event Reporting System (VAERS) after co-administration of mRNA COVID-19 and seasonal influenza vaccines.MethodsWe searched the VAERS database for reports of adverse events (AEs) following co-administration of mRNA COVID-19 and seasonal influenza vaccines and following a first booster dose mRNA COVID-19 vaccine alone, during July 1, 2021–June 30, 2022. We assessed the characteristics of these reports and described the most frequently reported MedDRA preferred terms (PTs). Clinicians reviewed available medical records for serious reports and reports of adverse events of special interest (AESI) and categorized the main diagnosis by system organ class.ResultsFrom July 1, 2021 through June 30, 2022, VAERS received 2,449 reports of adverse events following co-administration of mRNA COVID-19 and seasonal influenza vaccines. Median age of vaccinees was 48 years (IQR: 31, 66); 387 (15.8%) were classified as serious. Most reports (1,713; 69.3%) described co-administration of a first booster dose of an mRNA COVID-19 vaccine with seasonal influenza vaccine. The most common AEs among non-serious reports were injection site reactions (193; 14.5%), headache (181; 13.6%), and pain (171; 12.8%). The most common AEs among reports classified as serious were dyspnea (38; 14.9%), COVID-19 infection (32; 12.6%), and chest pain (27; 10.6%).DiscussionThis review of reports to VAERS following co-administration of mRNA COVID-19 and seasonal influenza vaccines did not reveal any unusual or unexpected patterns of AEs. Increased reporting of certain events (e.g., COVID-19 disease) was expected. CDC will continue to monitor the safety of co-administration of mRNA COVID-19 and seasonal influenza vaccines, including co-administration involving bivalent mRNA COVID-19 booster vaccines that have been recommended for people ages ≥ 6 months in the United States.     

COVID-19 vaccine safety monitoring in Republic of Korea from February 26, 2021 to October 31, 2021

ObjectivesThis study aimed to present data on reported adverse events following coronavirus disease 2019 (COVID-19) vaccination in Republic of Korea from February 26 to October 31, 2021, and to determine whether any significant patterns emerged from an analysis of the characteristics of suspected adverse event cases for each type of vaccine.MethodsAdverse events following COVID-19 vaccination reported by medical doctors and forensic pathologists were analyzed. Cases of suspected anaphylaxis were classified using the Brighton Collaboration definition.ResultsBy October 31, 2021, a total of 353,535 (0.45%) adverse events were reported after 78,416,802 COVID-19 vaccine doses. Of the adverse events, 96.4% were non-serious and 3.6% were serious. The most frequently reported adverse events were headache, myalgia, and dizziness. Of the 835 reported deaths after COVID-19 vaccination, 2 vaccine-related deaths were confirmed. Suspected anaphylaxis was confirmed in 454 cases using the Brighton Collaboration definition.ConclusionThe commonly reported symptoms were similar to those described in clinical trials. Most reported adverse events were non-serious, and the reporting rate of adverse events following COVID-19 vaccination was higher in women than in men (581 vs. 315 per 100,000 vaccinations). Confirmed anaphylaxis was reported in 5.8 cases per 1,000,000 vaccinations.     

Protection of vaccination versus hybrid immunity against infection with COVID-19 Omicron variants among Health-Care Workers

Background aimThe Omicron COVID-19 variants BA.1* and BA.2* evade immune system leading to increased transmissibility and breakthrough infections. We aim to test the hypothesis that immunity achieved post COVID-19 infection combined with vaccination (hybrid immunity), is more effective against Omicron infection than vaccination alone in a health-care setting.MethodsData on regular pre-emptive PCR testing from all Health-Care Workers (HCWs) at Laiko University Hospital from 29th December 2020, date on which the national COVID-19 immunization program began in Greece, until 24th May 2022, were retrospectively collected and recorded. The infection rate was calculated after December 21st, 2021, when Omicron was the predominant circulating variant in Greece, as the total number of infections (positive PCR COVID-19 test regardless of symptoms) divided by the total person-months at risk.ResultsOf 1,305 vaccinated HCWs who were included in the analysis [median age of 47 (IQR: 36, 56) years, 66.7 % women], 13 % and 87 % had received 2 or 3 vaccine doses (full and booster vaccination), respectively. A COVID-19 infection had occurred in 135 of 1,305 of participants prior to Omicron predominance. Of those 135 HCWs with hybrid immunity only 13 (9.6 %) were re-infected. Of the 154 and 1,016 HCWs with full and booster vaccination-induced immunity, respectively, 71 (46.1 %, infection rate 13.4/100 person-months) and 448 (44.1 %, infection rate 12.2/100 person-months) were infected during the follow up period. No association between gender or age and COVID-19 infection was found and none of the participants had a severe infection or died.ConclusionsHybrid immunity confers higher protection by almost 5-fold compared to full or booster vaccination for COVID-19 infection with the Omicron variant among HCWs who are at high risk of exposure. This may inform public health policies on how to achieve optimal immunity in terms of the timing and mode of vaccination.     

COVID-19 vaccine perceptions and hesitancy amongst parents of school-aged children during the pediatric vaccine rollout

BackgroundThe United States has the highest number of total cases and deaths due to coronavirus disease 2019 (COVID-19) worldwide (Johns Hopkins COVID Dashboard, 2021). Despite COVID-19 vaccine availability, uptake in the United States has been slow and vaccine hesitancy has been a significant barrier to achieving widespread vaccine uptake. Understanding determinants of vaccine acceptance is essential to implement successful population health interventions to increase COVID-19 vaccination.MethodsWe developed an anonymous cross-sectional parent survey to assess factors associated with parent and child COVID-19 vaccine acceptance and hesitancy during the initial pediatric vaccine rollout amongst adolescents 16 years +. The survey was sent via email to 25,308 parents registered to the Alachua County Public School System in May 2021 and remained active until July 2021.FindingsThere were a total of 2,620 survey responses. Overall, 31.5 % of parents with children ages 16 years + reported their child had received the COVID-19 vaccine, 65.2 % reported their (eligible) child had not received the vaccine, and 3.3 % reported their child was scheduled for the vaccine. A majority of parents (60.9 %) reported they planned to vaccinate all of their children once the COVID-19 vaccine was available for their children’s age. COVID-19 vaccine uptake in adolescents ages 16 + reported by Hispanic and White parents was two times higher than that reported by Black parents. Parent COVID-19 and influenza vaccine uptake were associated with increased child COVID-19 vaccination. The most commonly reported reasons why parents chose not to have their child vaccinated against COVID-19 were concerns about long–term negative side effects (75.7 %) and a negative reaction (56.5 %). Medical providers were reported as the most trusted source of information.ConclusionOur study provides insight into determinants of vaccine acceptance, vaccine hesitancy, and trusted sources of information that may be helpful to develop targeted interventions to increase youth COVID-19 vaccination.     

Aiming too high: Shoulder injury related to vaccine administration (SIRVA): A case series

PurposeShoulder injury directly related to vaccination (SIRVA) occurs when a vaccine is administered too high in the shoulder. The primary aim of this study was to accurately detail the occurrence, symptoms, diagnosis, management and long-term outcomes of SIRVA cases in Victoria, Australia.Principal resultsThe study identified 102 SIRVA cases from 2007 to 2020 from the Surveillance of Adverse Events Following Vaccination in the Community (SAEFVIC) database. The majority [73/85; (86 %)] of cases resolved completely with a median time to resolution of 8 weeks and no statistically significant difference in recovery by immunisation provider type or baseline imaging.Major conclusionsThis large case series includes long-term clinical progress in SIRVA, allowing accurate evaluation and analysis. Further evaluation is required to establish if other risk factors contribute to SIRVA, which may help with targeted, tailored education for providers on correct vaccine administration technique, including in large and rapid vaccine rollouts.     

Real-world uptake of COVID-19 vaccination among individuals expressing vaccine hesitancy: A registry-linkage study

Introduction Uptake of COVID-19 vaccination remains suboptimal in the United States and other settings. Though early reports indicated that a strong majority of people were interested in receiving the COVID-19 vaccine, the association between vaccine intention and uptake is not yet fully understood. Our objective was to describe predictors of vaccine uptake, and estimate the sensitivity, specificity, and predictive values of self-reported COVID-19 vaccine status compared to a comprehensive statewide COVID-19 vaccine registry.Methods A cohort of California residents that received a molecular test for SARS-CoV-2 infection during 24 February-5 December 2021 were enrolled in a telephone-administered survey. Survey participants were matched with records in a statewide immunization registry. Cox proportional hazards model were used to compare time to vaccination among those unvaccinated at survey enrollment by self-reported COVID-19 vaccination intention.ResultsAmong 864 participants who were unvaccinated at the time of interview, 272 (31%) had documentation of receipt of COVID-19 vaccination at a later date; including 194/423 (45.9%) who had initially reported being willing to receive vaccination, 41/185 (22.2%) who reported being unsure about vaccination, and 37/278 (13.3%) who reported unwillingness to receive vaccination. Adjusted hazard ratios (aHRs) for registry-confirmed COVID-19 vaccination were 0.49 (95% confidence interval: 0.32–0.76) and 0.21 (0.12–0.36) for participants expressing uncertainty and unwillingness to receive vaccination, respectively, as compared with participants who reported being willing to receive vaccination. Time to vaccination was shorter among participants from higher-income households (aHR = 3.30 [2.02–5.39]) and who reported co-morbidities or immunocompromising conditions (aHR = 1.54 [1.01–2.36]). Sensitivity of self-reported COVID-19 vaccination status was 82% (80–85%) overall, and 98% (97–99%) among those referencing vaccination records; specificity was 87% (86–89%).ConclusionWillingness to receive COVID-19 vaccination was an imperfect predictor of real-world vaccine uptake. Improved messaging about COVID-19 vaccination regardless of previous SARS-CoV-2 infection status may help improve uptake.     

Spontaneous reports of primary ovarian insufficiency after vaccination: A review of the vaccine adverse event reporting system (VAERS)

BackgroundSince 2012, reports of primary ovarian insufficiency (POI) temporally associated with receipt of human papillomavirus (HPV) vaccine have been published leading to questions about a potential causal association. A Vaccine Safety Datalink study did not find an increased risk for POI after vaccination. We reviewed the Vaccine Adverse Event Reporting System (VAERS) to describe POI reports.MethodsWe searched VAERS, a U.S. passive surveillance system, for domestic POI reports received from 01/01/1990 to 12/31/2017 after any vaccination. The search used both Medical Dictionary for Regulatory Activity Preferred Terms and a text-based search for POI and its symptoms. All reports were reviewed, and the American College of Obstetricians and Gynecologists (ACOG) guidelines for POI diagnosis were applied. Data mining for disproportionate reporting was conducted.ResultsSix hundred fifty-two reports met the search criteria and clinical review identified 19 POI reports. Most reports (n = 16) were received between 2013 and 2017. The median age at vaccination was 14.5 years (range 10–25 years) and the median interval between first dose of vaccination and reporting the event to VAERS was 43 months (range 4–132 months; mean 59.6 months). Four reports met ACOG diagnostic criteria; one with an underlying cause (47XXX chromosomal abnormality) reported. Eleven reports documented menstrual irregularity ≥ 3 months; 5 had ≥ 1 laboratory test result used to diagnose POI. Eighteen of 19 reports described receipt of HPV vaccine with or without other vaccines. Other vaccines reported were meningococcal conjugate vaccine, hepatitis A, varicella and tetanus toxoid, reduced diphtheria toxoid and acellular pertussis. Disproportionate reporting was found for three relevant coding terms after HPV vaccination.ConclusionsPOI is rarely reported to VAERS. Most reports contained limited diagnostic information and were submitted after published cases of POI following HPV vaccination. Results of our review do not suggest a safety concern.     

Vaccine effectiveness against COVID-19 related hospital admission in the Netherlands: A test-negative case-control study

IntroductionReal-world vaccine effectiveness (VE) estimates are essential to identify potential groups at higher risk of break-through infections and to guide policy. We assessed the VE of COVID-19 vaccination against COVID-19 hospitalization, while adjusting and stratifying for patient characteristics.MethodsWe performed a test-negative case-control study in six Dutch hospitals. The study population consisted of adults eligible for COVID-19 vaccination hospitalized between May 1 and June 28, 2021 with respiratory symptoms. Cases were defined as patients who tested positive for SARS-CoV-2 by PCR during the first 48 h of admission or within 14 days prior to hospital admission. Controls were patients tested negative at admission and did not have a positive test during the 2 weeks prior to hospitalization. VE was calculated using multivariable logistic regression, adjusting for calendar week, sex, age, comorbidity and nursing home residency. Subgroup analysis was performed for age, sex and different comorbidities. Secondary endpoints were ICU-admission and mortality.Results379 cases and 255 controls were included of whom 157 (18%) were vaccinated prior to admission. Five cases (1%) and 40 controls (16%) were fully vaccinated (VE: 93%; 95% CI: 81 – 98), and 40 cases (11%) and 70 controls (27%) were partially vaccinated (VE: 70%; 95% CI: 50–82). A strongly protective effect of vaccination was found in all comorbidity subgroups. No ICU-admission or mortality were reported among fully vaccinated cases. Of unvaccinated cases, mortality was 10% and 19% was admitted at the ICU.ConclusionCOVID-19 vaccination provides a strong protective effect against COVID-19 related hospital admission, in patients with and without comorbidity.     

Thrombocytopenia after Ad.26.COV2.S COVID-19 vaccine: Reports to the vaccine adverse event reporting system

BackgroundOn February 27, 2021, the Food and Drug Administration (FDA) issued an Emergency Use Authorization for Ad.26.COV2.S COVID-19 vaccine. As part of post-authorization safety surveillance, the FDA has identified a potential safety concern for thrombocytopenia following receipt of Ad.26.COV2.S COVID-19 vaccine.MethodsReports of thrombocytopenia were identified in a passive reporting system (Vaccine Adverse Event Reporting System; VAERS) February-December 2021. Demographics, clinical characteristics, laboratory values, and relevant medical history were reviewed. The reporting rate was analyzed, including calculation of the observed-to-expected ratio based on vaccine administration data and the background rate of thrombocytopenia in the general (unvaccinated) population.ResultsAs of December 31, 2021, 100 reports of thrombocytopenia were identified in VAERS following vaccination with Ad.26.COV2.S. The median platelet count was 33,000 per µL (interquartile range 8,000–86,000). Fifteen reports (15%) documented a platelet count of 5,000 per µL or lower. The median time to onset of thrombocytopenia was 9 days (interquartile range 3–18.5), with most cases (69; 69%) beginning within 14 days after vaccination. A large majority of cases (84; 84%) were serious, including six deaths. With approximately 16,292,911 doses of Ad.26.COV2.S administered to adults in the US, the crude reporting rate was 0.61 cases of thrombocytopenia per 100,000 doses administered. The overall estimated observed-to-expected rate ratio was 2.43 (95% CI 1.97, 2.95).ConclusionsThese findings suggest an increased risk of thrombocytopenia following receipt of Ad.26.COV2.S.     

Post-licensure surveillance of 13-valent pneumococcal conjugate vaccine (PCV13) in adults aged ⩾19 years old in the United States,Vaccine Adverse Event Reporting System (VAERS), June 1, 2012–December 31, 2015

BackgroundThe 13-valent pneumococcal conjugate vaccine (PCV13) was first recommended for use in adults aged ⩾19 years with immunocompromising conditions in June 2012. On August 2014, the Advisory Committee on Immunization Practices (ACIP) recommended routine use of PCV13 among adults aged ⩾65 years.MethodsWe assessed adverse events (AEs) reports following PCV13 in adults aged ⩾19 years reported to the Vaccine Adverse Event Reporting System (VAERS) from June 2012 to December 2015. VAERS is a national spontaneous reporting system for monitoring AEs following vaccination. Our assessment included automated data analysis, clinical review of all serious reports and reports of special interest. We conducted empirical Bayesian data mining to assess for disproportionate reporting.ResultsVAERS received 2976 US PCV13 adult reports; 2103 (71%) of these reports were from PCV13 administered alone. Fourteen percent were in persons aged 19–64 years and 86% were in persons aged ⩾65 years. Injection site erythema (28%), injection site pain (24%) and fever (22%) were the most frequent AEs among persons aged 19–64 years; injection site erythema (30%), erythema (20%) and injection site swelling (18%) were the most frequent among persons aged ⩾65 years who were given the vaccine alone. The most frequently reported AEs among non-death serious reports were injection site reactions and general malaise among persons 19–64 years old; injection site reactions, general malaise and Guillain-Barré syndrome among those ⩾65 years (Table 2). Data mining did not detect disproportional reporting for any unexpected AE.ConclusionsThe results of this study were consistent with safety data from pre-licensure studies of PCV13. We did not detect any new or unexpected AEs.     

Optimizing needle length and site choice for adult immunization

BackgroundCurrent recommendations for needle length and vaccination site for intramuscular deltoid vaccinations are backed by minimal data.AimTo determine the ideal needle length and vaccination site for intramuscular deltoid vaccine administration.Methods120 shoulder CT scans were evaluated and grouped by patient weight and sex as recommended by the United States CDC: Group 1, <60 kg, Group 2, 60–70 kg, Group 3, females 70–90 kg and males 70–118 kg, and Group 4, females > 90 kg and males > 118 kg. For each group, distance from skin to deltoid fascia and deltoid muscle width were measured at 2, 4, and 6 cm distal to the posterolateral corner of the acromion for 5 unique trajectories. Needle lengths of 0.625″, 1.0″, and 1.5″ were simulated at each site to determine inoculation location relative to the deltoid.ResultsFor Group 1, a 0.625″ needle in the mid-lateral (ML) trajectory 4 cm distal to the posterolateral corner provided a perfect rate of successful inoculations (100 %). For Groups 2–3, a 1″ needle in the posterolateral (PL) trajectory 4 cm distal provided high rates (>80 %) of successful intramuscular inoculations with low rates of overpenetration (<15 %) while minimizing risk to the axillary nerve. For Group 4, a 1.5″ needle using the same strategy provided the highest rate of successful inoculations (96 %) and minimal overpenetration (4 %). Overpenetration was associated with more anterior and superior injection sites (P < 0.001 for both) for all needle lengths.ConclusionsThe overall ideal injection site to maximize successful intramuscular vaccine administration, minimize overpenetration, and avoid axillary nerve injury is 4 cm distal to and in line with the posterolateral corner of the acromion, a site more posterior and inferior than current CDC recommendations. We caution against use of a 1.5″ needle for patients < 118 kg due to high predicted rates of overpenetration.     

Predictors of COVID-19 vaccine uptake among people who inject drugs

IntroductionWe studied characteristics of COVID-19 vaccination uptake among people who inject drugs (PWID).MethodsParticipants aged ≥18 years who injected drugs ≤1 month ago were recruited into a community-based cohort from October 2020 to September 2021 in San Diego, California Poisson regression identified correlates of having had ≥1 COVID-19 vaccine dose based on semi-annual follow-up interviews through March 15, 2022.ResultsOf 360 participants, 74.7% were male, mean age was 42 years; 63.1% were Hispanic/Mexican/Latinx. More than one-third had ≥1 co-morbidity. HIV and HCV seroprevalence were 4.2% and 50.6% respectively; 41.1% lacked health insurance. Only 37.8% reported having ≥1 COVID-19 vaccine dose. None received ≥3 doses. However, of those vaccinated, 37.5% were previously unwilling/unsure about COVID-19 vaccines. Believing COVID-19 vaccines include tracking devices (adjusted incidence rate ratio [aIRR]: 0.62; 95% CI: 0.42,0.92) and lacking health insurance (aIRR: 0.60; 95% CI: 0.40,0.91) were associated with approximately 40% lower COVID-19 vaccination rates). Ever receiving influenza vaccines (aIRR: 2.16; 95%CI: 1.46, 3.20) and testing HIV-seropositive (aIRR: 2.51; 95% CI: 1.03, 6.10) or SARS-CoV-2 RNA-positive (aIRR: 1.82; 95% CI: 1.05, 3.16) independently predicted higher COVID-19 vaccination rates. Older age, knowing more vaccinated people, and recent incarceration were also independently associated with higher COVID-19 vaccination rates.ConclusionsOne year after COVID-19 vaccines became available to U.S. adults, only one third of PWID had received ≥1 COVID-19 vaccine dose. Multi-faceted approaches that dispel disinformation, integrate public health and social services and increase access to free, community-based COVID-19 vaccines are urgently needed.     

Seasonal influenza vaccination in the Americas: Progress and challenges during the COVID-19 pandemic

BackgroundVaccination is one of the most effective measures to prevent influenza illness and its complications; influenza vaccination remained important during the COVID-19 pandemic to prevent additional burden on health systems strained by COVID-19 demand.ObjectivesWe describe policies, coverage, and progress of seasonal influenza vaccination programs in the Americas during 2019–2021 and discuss challenges in monitoring and maintaining influenza vaccination coverage among target groups during the COVID-19 pandemic.MethodsWe used data on influenza vaccination policies and vaccination coverage reported by countries/territories via the electronic Joint Reporting Form on Immunization (eJRF) for 2019–2021. We also summarized country vaccination strategies shared with PAHO.ResultsAs of 2021, 39 (89 %) out of 44 reporting countries/territories in the Americas had policies for seasonal influenza vaccination. Countries/territories adapted health services and immunization delivery strategies using innovative approaches, such as new vaccination sites and expanded schedules, to ensure continuation of influenza vaccination during the COVID-19 pandemic. However, among countries/territories that reported data to eJRF in both 2019 and 2021, median coverage decreased; the percentage point decrease was 21 % (IQR = 0–38 %; n = 13) for healthcare workers, 10 % (IQR = -1.5–38 %; n = 12) for older adults, 21 % (IQR = 5–31 %; n = 13) for pregnant women, 13 % (IQR = 4.8–20.8 %; n = 8) for persons with chronic diseases, and 9 % (IQR = 3–27 %; n = 15) for children.ConclusionsCountries/territories in the Americas successfully adapted influenza vaccination delivery to continue vaccination services during the COVID-19 pandemic; however, reported influenza vaccination coverage decreased from 2019 to 2021. Reversing declines in vaccination will necessitate strategic approaches that prioritize sustainable vaccination programs across the life course. Efforts should be made to improve the completeness and quality of administrative coverage data. Lessons learned from COVID-19 vaccination, such as the rapid development of electronic vaccination registries and digital certificates, might facilitate advances in coverage estimation.     

Veteran influenza vaccination acceptance rates after completion of the COVID-19 vaccination series among historical influenza vaccine refusers

BackgroundVaccine hesitancy remains an obstacle in disease prevention. The recent COVID-19 pandemic highlighted this issue and may influence acceptance of other recommended immunizations. The objective of this study was to determine the association between receiving the COVID-19 vaccination and the subsequent acceptance of the influenza vaccination in a Veteran population that historically declined influenza vaccination.MethodsInfluenza vaccination acceptance rates for the 2021–2022 influenza season were compared in patients who historically declined the influenza vaccine and either received or declined COVID-19 vaccinations. Logistic regression analysis was used to analyze factors associated with receiving influenza vaccination among vaccine hesitant individuals.ResultsA higher proportion of patients who had received the COVID-19 vaccination(s) subsequently accepted the influenza vaccination compared to the control group (37% vs. 11%, OR = 5.03; CI 3.15–8.26; p = 0.0001).ConclusionAmong previous influenza vaccine decliners, those who received COVID-19 vaccination had significantly higher odds of receiving subsequent influenza vaccination.