scholarly journals Influence of Prior Influenza Vaccination on Current Influenza Vaccine Effectiveness in Children Aged 1 to 5 Years

Vaccines ◽  
2021 ◽  
Vol 9 (12) ◽  
pp. 1447
Author(s):  
Kazuhiro Matsumoto ◽  
Wakaba Fukushima ◽  
Saeko Morikawa ◽  
Masashi Fujioka ◽  
Tohru Matsushita ◽  
...  

Background: Although annual influenza vaccination is an important strategy used to prevent influenza-related morbidity and mortality, some studies have reported the negative influence of prior vaccination on vaccine effectiveness (VE) for current seasons. Currently, the influence of prior vaccination is not conclusive, especially in children. Methods: We evaluated the association between current-season VE and prior season vaccination using a test-negative design in children aged 1–5 years presenting at nine outpatient clinics in Japan during the 2016/17 and 2017/18 influenza seasons. Children with influenza-like illness were enrolled prospectively and tested for influenza using real-time RT-PCR. Their recent vaccination history was categorized into six groups according to current vaccination doses (0/1/2) and prior vaccination status (unvaccinated = 0 doses/vaccinated = 1 dose or 2 doses): (1) 0 doses in the current season and unvaccinated in prior seasons (reference group); (2) 0 doses in the current season and vaccinated in a prior season; (3) 1 dose in the current season and unvaccinated in a prior season; (4) 1 dose in the current season and vaccinated in a prior season; (5) 2 doses in the current season and unvaccinated in a prior season, and (6) 2 doses in the current season and vaccinated in a prior season. Results: A total of 799 cases and 1196 controls were analyzed. The median age of the subjects was 3 years, and the proportion of males was 54%. Overall, the vaccination rates (any vaccination in the current season) in the cases and controls were 36% and 53%, respectively. The VEs of the groups were: (2) 29% (95% confidence interval: −25% to 59%); (3) 53% (6% to 76%); (4) 70% (45% to 83%); (5) 56% (32% to 72%), and (6) 61% (42% to 73%). The one- and two-dose VEs of the current season were significant regardless of prior vaccination status. The results did not differ when stratified by influenza subtype/lineage. Conclusion: Prior vaccination did not attenuate the current-season VE in children aged 1 to 5 years, supporting the annual vaccination strategy.

2021 ◽  
Vol 26 (32) ◽  
Author(s):  
Iván Martínez-Baz ◽  
Ana Navascués ◽  
Itziar Casado ◽  
Aitziber Aguinaga ◽  
Carmen Ezpeleta ◽  
...  

Background Most reports of influenza vaccine effectiveness consider current-season vaccination only. Aim We evaluated a method to estimate the effect of influenza vaccinations (EIV) considering vaccination history. Methods We used a test-negative design with well-documented vaccination history to evaluate the average EIV over eight influenza seasons (2011/12–2018/19; n = 10,356). Modifying effect was considered as difference in effects of vaccination in current and previous seasons and current-season vaccination only. We also explored differences between current-season estimates excluding from the reference category people vaccinated in any of the five previous seasons and estimates without this exclusion or only for one or three previous seasons. Results The EIV was 50%, 45% and 38% in people vaccinated in the current season who had previously received none, one to two and three to five doses, respectively, and it was 30% and 43% for one to two and three to five prior doses only. Vaccination in at least three previous seasons reduced the effect of current-season vaccination by 12 percentage points overall, 31 among outpatients, 22 in 9–65 year-olds, and 23 against influenza B. Including people vaccinated in previous seasons only in the unvaccinated category underestimated EIV by 9 percentage points on average (31% vs 40%). Estimates considering vaccination of three or five previous seasons were similar. Conclusions Vaccine effectiveness studies should consider influenza vaccination in previous seasons, as it can retain effect and is often an effect modifier. Vaccination status in three categories (current season, previous seasons only, unvaccinated) reflects the whole EIV.


Author(s):  
Mark W Tenforde ◽  
H Keipp Talbot ◽  
Christopher H Trabue ◽  
Manjusha Gaglani ◽  
Tresa M McNeal ◽  
...  

Abstract Background Influenza causes significant morbidity and mortality and stresses hospital resources during periods of increased circulation. We evaluated the effectiveness of the 2019-2020 influenza vaccine against influenza-associated hospitalizations in the United States. Methods We included adults hospitalized with acute respiratory illness at 14 hospitals and tested for influenza viruses by reserve transcription polymerase chain reaction. Vaccine effectiveness (VE) was estimated by comparing the odds of current-season influenza vaccination in test-positive influenza cases versus test-negative controls, adjusting for confounders. VE was stratified by age and major circulating influenza types along with A(H1N1)pdm09 genetic subgroups. Results 3116 participants were included, including 18% (553) influenza-positive cases. Median age was 63 years. Sixty-seven percent (2079) received vaccination. Overall adjusted VE against influenza viruses was 41% (95% confidence interval [CI]: 27-52). VE against A(H1N1)pdm09 viruses was 40% (95% CI: 24-53) and 33% against B viruses (95% CI: 0-56). Of the two major A(H1N1)pdm09 subgroups (representing 90% of sequenced H1N1 viruses), VE against one group (5A+187A,189E) was 59% (95% CI: 34-75) whereas no significant VE was observed against the other group (5A+156K) [-1%, 95% CI: -61-37]. Conclusions In a primarily older population, influenza vaccination was associated with a 41% reduction in risk of hospitalized influenza illness.


Author(s):  
Iván Martínez-Baz ◽  
Ana Navascués ◽  
María Eugenia Portillo ◽  
Itziar Casado ◽  
Ujué Fresán ◽  
...  

Abstract Background People with diabetes are at high risk of severe influenza complications. The influenza vaccination effect among diabetic patients remains inconclusive. We estimated the average effect of influenza vaccination status in the current and prior seasons in preventing laboratory-confirmed influenza hospitalization in diabetic patients. Methods Patients attended in hospitals and primary healthcare centers with influenza-like illness were tested for influenza from the 2013–2014 to 2018–2019 seasons in Navarre, Spain. A test-negative case-control design in diabetic inpatients compared the influenza vaccination status in the current and 5 prior seasons between laboratory-confirmed influenza cases and negative controls. Vaccination status of influenza-confirmed cases was compared between diabetic inpatients and outpatients. Influenza vaccination effect was compared between diabetic patients and older (≥ 60 years) or chronic nondiabetic patients. Results Of 1670 diabetic inpatients tested, 569 (34%) were confirmed for influenza and 1101 were test-negative controls. The average effect in preventing influenza hospitalization was 46% (95% confidence interval [CI], 28%–59%) for current-season vaccination and 44% (95% CI, 20%–61%) for vaccination in prior seasons only in comparison to unvaccinated patients in the current and prior seasons. Among diabetic patients with confirmed influenza, current-season vaccination reduced the probability of hospitalization (adjusted odds ratio, 0.35; 95% CI, .15–.79). In diabetic patients, vaccination effect against influenza hospitalizations was not inferior to that in older or chronic nondiabetic patients. Conclusions On average, influenza vaccination of diabetic population reduced by around half the risk of influenza hospitalization. Vaccination in prior seasons maintained a notable protective effect. These results reinforce the recommendation of influenza vaccination for diabetic patients.


Author(s):  
M. J. Rensink ◽  
H. W. M. van Laarhoven ◽  
F. Holleman

Abstract Purpose Oncological patients are susceptible to various severe viral infections, including influenza. Vaccinating oncological patients and their household contacts (“cocoon vaccination”) may protect these patients from contracting influenza. To understand the potential of cocoon vaccination in oncological patients, this study assesses the influenza vaccination status of oncological patients and their household contacts and their considerations regarding the vaccination. Methods In this retrospective study, oncological patients with a solid tumor were asked to fill in a questionnaire about their own and their household contacts’ influenza vaccination status in the influenza season of 2018–2019. Results Ninety-eight patients were included (response rate 88%). The influenza vaccination rates of oncological patients and their first household contacts were 43.9% and 44.9%, respectively. The majority of vaccinated patients and vaccinated first household contacts had been advised by their general practitioner to get the vaccination. A minority of the first household contacts reported getting vaccinated specifically because of the patient’s vulnerability. Unvaccinated patients and unvaccinated household contacts mainly believed the vaccination was unnecessary or were afraid of side effects. None of the included patients had been hospitalized with influenza. Conclusion The oncological patients’ and first household contacts’ vaccination rates in this study were lower than the vaccination rates of the general Dutch population of over 60 years old, possibly due to a lack of knowledge and misconceptions about the vaccination. Further research is required to establish whether cocoon vaccination can contribute to protecting oncological patients from contracting an influenza infection.


2020 ◽  
Vol 174 (1) ◽  
pp. 86
Author(s):  
Claire Abraham ◽  
Qixuan Chen ◽  
Weijia Fan ◽  
Melissa S. Stockwell

2017 ◽  
Vol 4 (suppl_1) ◽  
pp. S60-S60
Author(s):  
Ashley Fowlkes ◽  
Hannah Friedlander ◽  
Andrea Steffens ◽  
Kathryn Como-Sabetti ◽  
Dave Boxrud ◽  
...  

Abstract Background Due to marked variability in circulating influenza viruses each year, annual evaluation of the vaccine’s effectiveness against severe outcomes is essential. We used the Minnesota Department of Health’s (MDH) Severe Acute Respiratory Illness (SARI) surveillance to evaluate vaccine effectiveness (VE) against influenza-associated hospitalization over three influenza seasons. Methods Residual respiratory specimens from patients admitted with SARI were sent to the MDH laboratory for influenza RT-PCR testing. Medical records were reviewed to collect patient data. Vaccination history was verified using the state immunization registry. We included patients aged ≥6 months to < 13 years, after which immunization reporting is not required, hospitalized from the earliest influenza detection after July through April each year. We defined vaccinated patients as those ≥1 dose of influenza vaccine in the current season. Children aged < 9 years with no history of vaccination were considered vaccinated if 2 were doses given a month apart. Partially vaccinated children were excluded. We estimated VE as 1 minus the adjusted odds ratio (x100%) of influenza vaccination among influenza cases vs. negative controls, controlling for age, race, days from onset to admission, comorbidities, and admission month. Results Among 2198 SARI patients, 763 (35%) were vaccinated for influenza, 180 (8.2%) were partially vaccinated, and 1255 (57%) were unvaccinated. Influenza was detected among 202 (9.2%) children, and significantly more frequently among children aged ≥5 years (17%) compared with younger children (7.4%). The adjusted VE in 2013–14 was 68% (95% Confidence Interval: 34, 85), but was non-significant during the 2014–15 and 2015–16 seasons (Figure). Estimates of VE by influenza A subtypes varied substantially by year; VE against influenza B viruses was significant, but could not be stratified by year. VE was impacted when live attenuated influenza vaccine recipients were excluded. Conclusion We report moderately high influenza VE in 2013–14 and a point estimate higher than other published estimates from outpatient data in 2014–15. These results, underscore the importance of influenza vaccination to prevent severe outcomes such as hospitalization. Disclosures All authors: No reported disclosures.


2018 ◽  
Vol 5 (suppl_1) ◽  
pp. S68-S68
Author(s):  
Jessie Chung ◽  
Brendan Flannery ◽  
Rodolfo Begue ◽  
Herve Caspard ◽  
Laurie Demarcus ◽  
...  

Abstract Background Quadrivalent live attenuated influenza vaccine (LAIV4) was not recommended for use in the United States for the 2016–2017 and 2017–2018 influenza seasons based on US observational studies of vaccine effectiveness (VE) from 2013–2014 to 2015–2016. We pooled individual patient data on children aged 2–17 years enrolled in 5 US studies during these 3 influenza seasons to further investigate VE by vaccine type. Methods Analyses included 17,173 children enrolled in the US Department of Defense Global Laboratory-based Influenza Surveillance Program, US Influenza Vaccine Effectiveness Network, Influenza Incidence Surveillance Project, Influenza Clinical Investigation for Children, and a Louisiana State University study. Participants’ specimens were tested for influenza by reverse transcription-polymerase chain reaction (RT-PCR), culture, or a combination of rapid antigen testing and RT-PCR. VE was calculated by comparing odds of vaccination with either inactivated influenza vaccine (IIV) or LAIV4 among influenza-positive cases to test-negative controls and calculated as 100 × (1 − odds ratio) in logistic regression models with age, calendar time, influenza season, and study site (random effect). Patients were stratified by prior season vaccination status in a subanalysis. Results Overall, 38% of patients (N = 6,558) were vaccinated in the current season, of whom 30% (N = 1,979) received LAIV4. Pooled VE of IIV against any influenza virus was 51% (95% CI: 47, 54) versus 26% (95% CI: 15, 36) for LAIV4. Point estimates for pooled VE against any influenza by age group ranged from 45% to 58% for IIV and 19% to 34% for LAIV4 during the 3 seasons (Figures 1 and 2). Pooled VE against influenza A(H1N1)pdm09 was 67% (95% CI: 62, 72) for IIV versus 20% (95% CI: −6, 39) for LAIV4. Pooled VE against influenza A(H3N2) was 29% (95% CI: 14, 42) for IIV versus 7% (95% CI: −11, 23) for LAIV4, and VE against influenza B was 52% (95% CI: 42, 60) for IIV and 66% (95% CI: 47, 77) for LAIV4. VE against influenza A(H1N1)pdm09 was lower for LAIV4 versus IIV across all strata of prior season vaccination (Figure 3). Conclusion Consistent with individual studies, our pooled analyses found that LAIV4 effectiveness was reduced for all age groups against influenza A(H1N1)pdm09 compared with IIV. This result did not vary based on prior vaccination status. Disclosures H. Caspard, AstraZeneca: Employee, Salary.


2021 ◽  
Author(s):  
G Gray ◽  
J Cooper

Abstract Background The annual influenza vaccination is recommended for all front-line healthcare workers in the UK and is a crucial way of reducing mortality for vulnerable patient groups. However, to date the UK government has never explicitly monitored influenza vaccine uptake in medical students. This is important to ascertain, as students regularly move between clinical areas and are both a perfect vector for the spread of influenza and at an increased risk of contracting influenza themselves. Aims This service evaluation was designed to evaluate the effectiveness of an influenza vaccination programme in one UK medical school and make recommendations to increase vaccination rates in the future. Methods This service evaluation collected data about medical student uptake of influenza vaccination in one UK medical school. Two hundred and fifty-one students at different course stages completed questionnaires, answering questions on vaccination status and Likert-scale ‘belief’ questions to assess the subjective reasons behind vaccine refusal. Results There was a substantial difference between year group cohorts (~20%), with significantly higher vaccination rates in the preclinical year group. Two significant negative predictors of vaccination were found (P < 0.001), related to scepticism over the effectiveness of the vaccine and lack of convenient access to the vaccination. Results indicated that integrating information about the influenza vaccine into the curriculum would reduce lack of knowledge over the efficacy of the vaccine. The centralization of vaccination programmes at mandatory university-based learning events would mitigate against the problem of diversity of vaccination locations and lack of central accountability. Conclusions The results of this service evaluation provide significant predictors of vaccination status for medical students and potential occupational health interventions to improve vaccine uptake in this group.


2021 ◽  
Author(s):  
Joshua G. Petrie ◽  
Helene Fligiel ◽  
Lois Lamerato ◽  
Emily T. Martin ◽  
Arnold S. Monto

ABSTRACTBackgroundDocumentation of influenza vaccination, including the specific product received, is critical to estimate annual vaccine effectiveness (VE).MethodsWe assessed performance of the Michigan Care Improvement Registry (MCIR) in defining influenza vaccination status relative to documentation by provider records or self-report among subjects enrolled in a study of influenza VE from 2011 through 2019.ResultsThe specificity and positive predictive value of MCIR were high; however, >10% of vaccinations were identified only by other sources each season. The proportion of records captured by MCIR increased from a low of 67% in 2013-2014 to a high of 89% in 2018-2019, largely driven by increased capture of vaccination among adults.ConclusionsState vaccine registries, such as MCIR, are important tools for documenting influenza vaccination, including the specific product received. However, incomplete capture suggests that documentation from other sources and self-report should be used in combination with registries to reduce misclassification.


Author(s):  
Julia Dratva ◽  
Aylin Wagner ◽  
Annina Zysset ◽  
Thomas Volken

The speed and innovation of the COVID-19 vaccine development has been accompanied by insecurity and skepticism. Young adults’ attitude to vaccination remains under investigation, although herd immunity cannot be reached without them. The HEalth in Students during the Corona pandemic study (HES-C) provided the opportunity to investigate vaccination intention in 1478 students in the sixth survey wave (January 2021), including vaccination intention, psychological antecedents of vaccine hesitancy, trust in government’s vaccination strategy, and vaccination history. Associations with vaccination intention were analyzed with multivariate ordinal regression and predicted margins were calculated adjusting for gender, age, anxiety, health profession, and subjective health status. A third was decided (yes 25.1%, no 7.6%), and 68% were unsure about getting the COVID-19 vaccine when available. Next to demographic characteristics, vaccination history (influenza vaccination OR = 1.39; 95% CI: 1.06–1.83, travel vaccination OR = 1.29; 95% CI: 1.04–1.60), trust in vaccination strategy (OR = 2.40; 95% CI: 1.89–3.05), and 5C dimensions were associated with vaccination intention: confidence (OR = 2.52; 95% CI: 2.09–3.03), complacency (OR = 0.79; 95% CI: 0.66–0.96), calculation (OR = 0.79; 95% CI: 0.70–0.89), constraints (OR = 1.18; 95% CI: 0.99–1.41), and collective responsibility (OR = 4.47; 95% CI: 3.69–5.40). Addressing psychological antecedents and strengthening trust in official strategies through targeted campaigns and interventions may increase decisiveness and result in higher vaccination rates.


Sign in / Sign up

Export Citation Format

Share Document