Types Of Influenza Vaccines Research Articles

Parental vaccine hesitancy and influenza vaccine type preferences during and after the COVID-19 Pandemic

BackgroundSeasonal influenza vaccine (SIV) greatly reduces disease burden among school-aged children, yet parental vaccine hesitancy remains a persistent challenge. Two types of SIV are available for children in Hong Kong and other locations: inactivated influenza vaccine (IIV), administered through intramuscular injection, and live attenuated influenza vaccine (LAIV), administered via nasal spray. We aimed to understand how vaccine hesitancy shaped parental preference for LAIV versus IIV, particularly amidst important public health events, such as the COVID-19 pandemic and the massive rollout of COVID-19 vaccination campaigns.MethodsWe employed a concurrent mixed-methods design. The quantitative part involves longitudinal surveys spanning three years, from pre-pandemic to post-pandemic periods, tracking parental vaccine hesitancy and preference for SIV types. The qualitative part involves 48 in-depth interviews, providing insights into parental preference for SIV types, underlying reasons, and related values.ResultsOur quantitative analyses show an overall increase in parental vaccine hesitancy and preference for LAIV over IIV after the onset of the COVID-19 pandemic and especially after the rollout of the COVID-19 vaccination campaign. Further logistic regression modelling based on the cohort data shows that higher vaccine hesitancy, coupled with the COVID-19 vaccination campaign rollout, predicts a greater preference for LAIV over IIV. The qualitative analysis complements these results, highlighting that LAIV’s non-invasive nature aligns with parental values of prioritizing natural immunity and concerns about overmedication, leading to a more acceptable attitude towards LAIV.ConclusionsLeveraging the higher acceptability of LAIV compared to IIV among parents with high vaccine hesitancy could promote childhood vaccination uptake.

Proportional of wheezing events in asthmatic children post-vaccination of annual flu vaccine

Background: The common childhood chronic disease asthma causes hospitalisation and exacerbations due to respiratory tract viral infections like influenza. Due to uncertainty about the benefits and role of influenza vaccines in preventing asthma exacerbations, many children with asthma do not receive them, despite recommendations from organisations like the Canadian National Advisory Committee on Immunisation. There are two main types of influenza vaccines: intramuscular trivalent inactivated and intranasal cold-adapted, live attenuated. Both vaccines are highly immunogenic and induce an adequate immune response, but their clinical efficacy varies by season and age. Aim: The aim of this study was to investigate the occurrence of increased wheeze rates in stable asthmatic children who received the annual flu vaccine, compared to a control group of asthmatic children who did not receive the vaccine. Methods: A retrospective study at the Queen Rania Abdullah for Children Hospital in Amman, Jordan, examined the vaccination status of 200 asthmatic children aged 3-14. The study focused on recurrent wheezing episodes and the minimum 12-month period between the last annual flu vaccination and asthmatic exacerbation. The study excluded uncontrolled or partially controlled patients for the past 12 months. Data was collected from demographic information, vaccination history, and past wheezing episodes. The children were divided into two groups, one without the flu vaccine and the other with the flu vaccine. A comprehensive questionnaire was used to assess sociodemographic and disease-related factors. If children received the vaccination as per the National Vaccination Schedule, their vaccination status was considered complete. Results: A study of 200 asthmatic children in Jordan found that 35% did not receive a flu vaccine, placing them in Group I. 65% had received a flu vaccine in the previous year. Males had higher distribution rates in both flu-based groups, with a statistically insignificant positive correlation. Age categories showed similar distribution rates, with 21.0% for 3-6 years, 34.0% for 6-9 years, 37.5% for 9-12 years, and 7.5% for 12-15 years. No significant correlation was found between receiving the flu vaccine and wheezing rates in the last seasonal year. Frequent wheezing episodes were higher in experienced groups than in naïve groups.

Impact of pharmacist interventions on immunisation uptake: a systematic review and meta-analysis.

Under-utilisation of immunisation services remains a public health challenge. Pharmacists act as facilitators and increasingly as immunisers, yet relatively little robust evidence exists of the impact elicited on patient health outcome and vaccination uptake. To evaluate the influence of pharmacist interventions on public vaccination rate. SCOPUS, PubMed, and Web of Science were searched from inception to April 2023 to retrieve non- and randomised controlled clinical trials (RCTs). Studies were excluded if no comparator group to pharmacist involvement was reported. Data extraction, risk of bias assessments, and meta-analyses using random-effect models, were performed. Four RCTs and 15 non-RCTs, encompassing influenza, pneumococcal, herpes zoster, and tetanus-diphtheria and pertussis vaccine types, and administered in diverse settings including community pharmacies, were included. Pooled effect sizes revealed that, as compared to usual care, pharmacists, regardless of their intervention, improved the overall immunisation uptake by up to 51% [RR 1.51 (1.28, 1.77)] while immunisation frequency doubled when pharmacists acted specifically as advocators [RR 2.09 (1.42, 3.07)]. While the evidence for pharmacist immunisers was mixed, their contribution to immunisation programmes boosted public vaccination rate. Pharmacists demonstrated leadership and acquired indispensable advocator roles in the community and hospital settings. Future research could explore the depth of engagement and hence the extent of influence on immunisation uptake.

The history of vaccine and vaccination against influenza in Poland

The influenza virus is an important cause of morbidity, complications and mortality worldwide. Anyone can be infected, regardless of latitude or age. The paper describes the history of obtaining a modern influenza vaccine that does not deviate from current World Health Organization standards in Poland. Dozens of studies assessing the post-vaccination humoral response for different types of influenza vaccine, measuring levels of anti-haemagglutinin and anti-neuraminidase antibodies (although not in all of the studies) have been presented. The research was conducted mainly in high-risk populations, regardless of the age of vaccine recipients. What is noteworthy, the paper presents specific examples that may help promote prevention and encourage healthcare personnel to protect not only patients, but also their relatives. Prophylaxis in the form of vaccination is the cheapest and most effective form of preventing both dangerous complications and mortality. Infection caused by the influenza virus should be viewed not only in the context of exacerbation of a pre-existing disease or causing a new disease, but also in terms of measurable public costs. There are many types of imported influenza vaccines available on the Polish pharmaceutical market, from the inactivated intramuscular split or subunit vaccine to the intranasal live vaccine obtained from strains adapted to lower replication temperatures. Currently, quadrivalent influenza vaccines, i.e. containing two influenza A virus subtypes (A/H1N1/pdm09, A/H3N2) and two influenza B virus lineages (Victoria and Yamagata), are used. Depending on the type of vaccine, immunisation is recommended from the age of 6 months, whereas the upper age limit is not specified. The composition of vaccines is updated every epidemic season.

Rollout of the 2022/2023 Seasonal Influenza Vaccination and Correlates of the Use of Enhanced Vaccines among Italian Adults.

In Italy, several types of seasonal influenza vaccines (SIVs) are available for older adults, but for the 2022/2023 season there were no guidelines on their specific use. This cross-sectional study assessed the frequency and determinants of the use of enhanced (adjuvanted and high-dose) SIVs in Italian older adults, as compared to standard-dose non-adjuvanted formulations. Of 1702 vaccines administered to a representative outpatient sample of adults aged ≥ 60 years and residing in Genoa, 69.5% were enhanced SIVs. Older age (adjusted odds ratio (aOR) for each 1-year increase 1.10; p < 0.001), and the presence of cardiovascular disease (aOR 1.40; p = 0.011) and diabetes (aOR 1.62; p = 0.005) were associated with the use of enhanced vaccines. Compared with the adjuvanted SIV, subjects immunized with the high-dose vaccine were older (aOR for each 1-year increase 1.05; p < 0.001) and had higher prevalence of respiratory diseases (aOR 1.85; p = 0.052). Moreover, usage of the enhanced SIVs was driven by the period of immunization campaign, place of vaccination and physician. Despite their superior immunogenicity and effectiveness, the adoption of enhanced SIVs in Italy is suboptimal, and should be increased. Enhanced formulations are mostly used in the oldest, and in subjects with some co-morbidities.

Multivariate analysis of the parameters of the immune response after immunization with inactivated influenza vaccines

Influenza A and B viruses are widely spread respiratory pathogens of humans and cause both isolated cases and local outbreaks of the disease, as well as massive seasonal epidemics and pandemics. Vaccination is the main strategy for combating influenza, and an increase in the proportion of vaccinated people in the population determines the success of vaccination. To identify patterns of postvaccination immune response formation to different types of vaccines and assess the significance of its multiple parameters the appropriate statistical methods should by applied. These methods allow to operate with large datasets and reduce their dimension, while keeping the maximum of information about the differences between individual observations. The aim of our study was the analysis of parameters of humoral and cellular immunity and their dynamics after vaccination with different types of inactivated influenza vaccines (IIV) using statistical methods of complex data analysis. The study was conducted in the clinical department of the Smorodintsev Research Institute of Influenza, Ministry of Health of the Russian Federation, in the flu season 2018 – 2019. The multivariate analysis of the immune response parameters after immunization with IIV “Grippol plus”, “Sovigripp” “Ultrix” included data obtained for 39 volunteers before vaccination, on the 7th and 21st days after vaccination. To identify parameters with significant differences between groups, one-factor analysis of variance (ANOVA) was used separately for each parameter and time point. To visualize the differences in the parameters selected in the analysis of variance, the Principal component analysis (PCA) method was used. The conducted studies revealed the peculiarities of the formation of a post-vaccination immune response to various types of IIV. It was shown that the factors of antigen-specific CD4+ and CD8+ T-cell immune response introduced the major contribution to the formation of the differences between groups. The approach is a powerful tool in analyzing the parameters of the immune response in clinical trials of influenza vaccines and other preventive medicine.

Influenza Vaccine Type-Dependent Antibody Response in Patients with Autoimmune Inflammatory Rheumatic Diseases.

The study aimed to explore influenza antibody response in patients with autoimmune inflammatory rheumatoid diseases (AIIRDs) stratified by the different vaccine types applied in Denmark during the 2018-2019 influenza season. Included patients were diagnosed with rheumatoid arthritis, psoriatic arthritis, or spondyloarthritis receiving biological disease-modifying antirheumatic drugs (bDMARDs) with or without conventional synthetic disease-modifying antirheumatic drugs. Influenza vaccination status in the 2018-2019 season and vaccine type received were reviewed in the Denmark. Blood samples were drawn ≥ 14 days post vaccination, and antibody titers were determined by the hemagglutinin inhibition (HAI) assay for the serotypes A/Michigan/H1N1, A/Singapore/H3N2, and B/Colorado included in the influenza vaccines in the 2018-2019 season. An overall serotype HAI geometric mean titer (GMT) was calculated from the 3 serotype-specific HAI titers. An overall serotype HAI GMT ≥ 40 was considered protective. Of the 205 included patients, 105 (51%) had received influenza vaccination. One-quarter of vaccinated patients achieved post-vaccination overall serotype HAI GMT ≥40. For patients vaccinated with Influvac, a significantly higher proportion had HAI titers ≥ 40 for 2 serotypes, namely, A/Michigan/H1N1 and A/Singapore/H3N2, than patients vaccinated with Vaxigrip or VaxigripTetra. The same applied to all serotypes HAI GMT, where significantly more patients who received Influvac achieved postvaccination HAI GMT≥40 versus patients who received Vaxigrip (p=0.02) or VaxigripTetra (p=0.002). The latter outcome was explored in a multivariable logistic regression analysis and remained significant when including the following variables: age, sex, treatment with methotrexate and/or prednisolone, type of influenza vaccine, time interval from vaccination to antibody measurement, and previous vaccination status. Influenza antibody levels following vaccination with Influvac in bDMARD-treated patients with AIIRDs were superior to Vaxigrip and VaxigripTetra. Treatment with methotrexate (MTX) did not reduce the antibody response.

OVERVIEW OF THE CURRENT SITUATION ON SEASONAL INFLUENZA VACCINES

Influenza virus infection causes seasonal epidemics and periodic pandemics, resulting in high morbidity and mortality worldwide. Vaccination is the most important tool for the prevention of influenza, while annual renewal of the composition of the vaccine is required due to the constant variability of the influenza virus. Epidemiological surveillance of the virus plays an important role in the better selection of candidate viruses for vaccines and early detection of drug-resistant strains.This work presents an overview of current vaccine options and existing vaccine candidate developments. Today, three types of influenza vaccines are licensed in the world: inactivated, live attenuated and recombinant. The effectiveness of the current version of the influenza vaccine is suboptimal and is estimated at 40–60% when the vaccine strains antigenically correspond well to the circulating viruses. In general, the influenza vaccine is effective against morbidity and mortality among the population from this infection. However, the effectiveness of the vaccine depends on a number of factors, such as the age of the vaccinated, the corresponding strain included in the vaccine, the circulating virus, the production process itself, and the subject's previous vaccination history. Next-generation vaccines, universal vaccines and combination vaccines are the result of modern achievements and the basis for the future development of influenza vaccines

Technical guidelines for seasonal influenza vaccination in China (2023-2024)

Technical guidelines for seasonal influenza vaccination in China (2023-2024)

Simultaneous administration of mRNA COVID-19 bivalent booster and influenza vaccines

The U.S. Food and Drug Administration authorized use of mRNA COVID-19 bivalent booster vaccines on August 31, 2022. Currently, CDC’s clinical guidance states that COVID-19 and other vaccines may be administered simultaneously. At time of authorization and recommendations, limited data existed describing simultaneous administration of COVID-19 bivalent booster and other vaccines. We describe simultaneous influenza and mRNA COVID-19 bivalent booster vaccine administration between August 31–December 31, 2022, among persons aged ≥6 months in the Vaccine Safety Datalink (VSD) by COVID-19 bivalent booster vaccine type, influenza vaccine type, age group, sex, and race and ethnicity. Of 2,301,876 persons who received a COVID-19 bivalent booster vaccine, 737,992 (32.1%) received simultaneous influenza vaccine, majority were female (53.1%), aged ≥18 years (91.4%), and non-Hispanic White (55.7%). These findings can inform future VSD studies on simultaneous influenza and COVID-19 bivalent booster vaccine safety and coverage, which may have implications for immunization service delivery.

Assessment of the humoral immune response in children after immunization with different types of inactivated influenza vaccines in the 2019-2020 season

Causing millions of cases worldwide every year, influenza is one of the most common respiratory infections. The effectiveness of influenza vaccination and the nature of the resulting immune response may vary depending on the vaccine composition and age group. Since children are at the highest risk of disease and act as the main carriers of influenza, the assessment of the immunological efficacy of vaccines in this group is crucial for controlling the epidemic. Therefore, this study aimed to evaluate the characteristics of the humoral immune response in children after immunization with various types of inactivated influenza vaccines. An observational study was conducted in the 2019-2020 season and involved 230 children (&lt; 18 years old) and a comparison group of 87 adults aged 18 to 60 years. The subjects, who provided informed consent to participate, were vaccinated with one of three vaccines (Grippol Plus, Sovigripp, or Ultrix) in an open-label fashion. The humoral immune response was assessed by measuring the hemagglutination inhibition (HI) titer in the paired sera taken before and three weeks after vaccination. The immunogenicity of the vaccines in the age group under 18, met the CPMP criteria for the assessment of inactivated influenza vaccines in terms of the fold increase in antibody titers and the proportion of individuals with seroconversion to all three components (A/H1N1pdm09, A/H3N2, and B/Victoria). Although 6 to 18-year-old participants showed a more robust immune response to the B/Victoria component compared to the adult participants (aged 18 to 60), it was insufficient to ensure that 70% of the participants have a protective antibody titer. A comparative analysis of the vaccines’ immunogenicity was carried out for a subgroup of children aged 6-18 who had initially low antibody levels at the time of vaccination. The analysis showed that the split vaccine Ultrix outperformed the adjuvanted vaccine Grippol Plus in generating an antibody response to the component B/Victoria; however, the antibody responses to the A/H1N1pdm09 and A/H3N2 components did not differ between the two vaccines. The children under 6 years of age demonstrated a less pronounced humoral immune response to vaccination compared with the other age groups, which may be due to the age-related characteristics of the immune system in children of preschool age.

Cutaneous Adverse Reactions Following Influenza Vaccination in Adults.

To review the literature on cutaneous reactions to the influenza vaccine in adults. Authors systematically searched three databases: PubMed, MEDLINE, and EMBASE. Case reports published between January 1, 1995 and December 31, 2020 that described a cutaneous reaction to any brand of the influenza vaccine in adults were included. Exclusion criteria included having the wrong study design, pediatric cases, publication prior to 1995, and lack of cutaneous reaction to the vaccine. A total of 232 articles were identified. After duplicate removal, title and abstract screening, and full-text screening, 29 studies were included in the final review. Data extracted included patient sex, age, type of influenza vaccine received, time from vaccine administration to cutaneous reaction, duration of cutaneous reaction, description of cutaneous reactions, treatments used, and the outcome (eg, resolution, reoccurrence, complications). The mean age of participants was 43.7 years (range, 19-82 years), and 60% were women (n = 18). The most frequent cutaneous reaction that occurred following influenza vaccination included erythematous macules/papules/plaques (n = 17 [56.7%]), vasculitic and purpuric rashes (n = 5 [16.7%]), and maculopapular (morbilliform) rashes (n = 3 [10.0%]). All patients received treatment, and 96.7% (n = 29) of the cutaneous manifestations were resolved. Most studies did not report any further complications upon follow-up. Understanding and identifying the relationship between the influenza vaccine and possible cutaneous manifestations can help providers predict and anticipate these adverse effects.

A systematic review of randomized clinical trials on quadrivalent influenza vaccines for adults

Abstract Background Vaccination is the most effective intervention to prevent influenza. Adults at risk of complications are among the targets of annual vaccination campaigns and can receive different types of quadrivalent influenza vaccines (QIV). To assess the immunogenicity of different QIVs we performed a systematic review of available randomized controlled trials (RCTs) with the aim of indirectly compare them through a network meta-analysis. Methods The systematic review was conducted in accordance with PRISMA-NMA guidelines. We systematically searched RCTs conducted in adults aged 18-64 years that assessed the immunogenicity, namely seroprotection and seroconversion rate (SPR and SCR), of any QIV compared to any comparator. The literature search was performed on three databases (Medline, Cochrane Library and Scopus) until March 30th, 2021. Results Twenty-four RCTs were included in the systematic review. A network meta-analysis was not possible: the assumption of transitivity was not satisfied. Therefore, we decided to combine data on immunogenicity and efficacy of each QIV through single meta-analyses in the presence of at least two studies. Live attenuated QIV showed the worst results in terms of both SCR and SPR. Standard dose egg based, low dose adjuvanted, cell based, recombinant and intradermal QIV showed similar SCR in respect to influenza strain A, whereas low dose adjuvanted QIV showed an overall better profile in respect to B lineages. Regarding SCR, the better results were issued by standard egg based, cell based, recombinant, and low dose adjuvanted QIVs. Conclusions Albeit an indirect comparison among different QIVs was not possible, the assessment of SCR and SPR provided an overview of their respective potentiality and criticality in adulthood. In particular attention should be paid to new generation influenza vaccines that can have an antigen sparing effect and to the collection of real world data to make comparison among different QIVs possible. Key messages • Available evidence does not allow to perform indirect comparison of the quadrivalent influenza vaccines for adults. • Some QIVs, including new generation ones, elicit a better antibody response.

Technical guidelines for seasonal influenza vaccination in China (2022-2023)

Technical guidelines for seasonal influenza vaccination in China (2022-2023)

Technical guidelines for seasonal influenza vaccination in China (2022-2023)

Technical guidelines for seasonal influenza vaccination in China (2022-2023)

Quadrivalent Vaccines for the Immunization of Adults against Influenza: A Systematic Review of Randomized Controlled Trials.

Vaccination is the most effective intervention to prevent influenza. Adults at risk of complications are among the targets of the vaccination campaigns and can be vaccinated with different types of quadrivalent influenza vaccines (QIVs). In the light of assessing the relative immunogenicity and efficacy of different QIVs, a systematic review was performed. Randomized controlled trials conducted in adults aged 18–64 years until 30 March 2021 were searched through three databases (Medline, Cochrane Library and Scopus). Twenty-four RCTs were eventually included. After data extraction, a network meta-analysis was not applicable due to the lack of common comparators. However, in the presence of at least two studies, single meta-analyses were performed to evaluate immunogenicity and efficacy; on the contrary, data from single studies were considered. Seroconversion rate for H1N1 was higher for standard QIVs, while for the remaining strains it was higher for low-dose adjuvanted QIVs. For seroprotection rate, the recombinant vaccine recorded the highest values for H3N2, while for the other strains, the cell-based QIVs achieved better results. In general, standard and cell-based QIVs showed an overall good immunogenicity profile. Nevertheless, as a relative comparative analysis was not possible, further research would be deserved.

Current Opinion in LAIV: A Matter of Parent Virus Choice.

Influenza is still a frequent seasonal infection of the upper respiratory tract, which may have deadly consequences, especially for the elderly. This is in spite of the availability of vaccines suggested for persons above 65 years of age. Two types of conventional influenza vaccines are currently licensed for use—live attenuated and inactivated vaccines. Depending on local regulatory requirements, live attenuated vaccines are produced by the reverse genetics technique or by classical reassortment in embryonated chicken eggs. Sometimes, the efficiency of classical reassortment is complicated by certain properties of the wild-type parent virus. Cases of low efficacy of vaccines have been noted, which, among other reasons, may be associated with suboptimal properties of the wild-type parent virus that are not considered when recommendations for influenza vaccine composition are made. Unfortunately, knowledge surrounding the roles of properties of the circulating influenza virus and its impact on the efficacy of the reassortment process, vaccination efficiency, the infectivity of the vaccine candidates, etc., is now scattered in different publications. This review summarizes the main features of the influenza virus that may dramatically affect different aspects of the preparation of egg-derived live attenuated vaccine candidates and their effectiveness. The author expresses her personal view, which may not coincide with the opinion of other experts in the field of influenza vaccines.

Influenza Viruses and Vaccines: The Role of Vaccine Effectiveness Studies for Evaluation of the Benefits of Influenza Vaccines.

Influenza is a vaccine preventable disease and vaccination remains the most effective method of controlling the morbidity and mortality of seasonal influenza, especially with respect to risk groups. To date, three types of influenza vaccines have been licensed: inactivated, live-attenuated, and recombinant haemagglutinin vaccines. Effectiveness studies allow an assessment of the positive effects of influenza vaccines in the field. The effectiveness of current influenza is suboptimal, being estimated as 40% to 60% when the vaccines strains are antigenically well-matched with the circulating viruses. This review focuses on influenza viruses and vaccines and the role of vaccine effectiveness studies for evaluating the benefits of influenza vaccines. Overall, influenza vaccines are effective against morbidity and mortality in all age and risk groups, especially in young children and older adults. However, the effectiveness is dependent on several factors such as the age of vaccinees, the match between the strain included in the vaccine composition and the circulating virus, egg-adaptations occurring during the production process, and the subject’s history of previous vaccination.

Adverse Events of Interest Following Influenza Vaccination in the First Season of Adjuvanted Trivalent Immunization: Retrospective Cohort Study.

BackgroundVaccination is the most effective form of prevention of seasonal influenza; the United Kingdom has a national influenza vaccination program to cover targeted population groups. Influenza vaccines are known to be associated with some common minor adverse events of interest (AEIs), but it is not known if the adjuvanted trivalent influenza vaccine (aTIV), first offered in the 2018/2019 season, would be associated with more AEIs than other types of vaccines.ObjectiveWe aim to compare the incidence of AEIs associated with different types of seasonal influenza vaccines offered in the 2018/2019 season.MethodsWe carried out a retrospective cohort study using computerized medical record data from the Royal College of General Practitioners Research and Surveillance Centre sentinel network database. We extracted data on vaccine exposure and consultations for European Medicines Agency–specified AEIs for the 2018/2019 influenza season. We used a self-controlled case series design; computed relative incidence (RI) of AEIs following vaccination; and compared the incidence of AEIs associated with aTIV, the quadrivalent influenza vaccine, and the live attenuated influenza vaccine. We also compared the incidence of AEIs for vaccinations that took place in a practice with those that took place elsewhere.ResultsA total of 1,024,160 individuals received a seasonal influenza vaccine, of which 165,723 individuals reported a total of 283,355 compatible symptoms in the 2018/2019 season. Most AEIs occurred within 7 days following vaccination, with a seasonal effect observed. Using aTIV as the reference group, the quadrivalent influenza vaccine was associated with a higher incidence of AEIs (RI 1.46, 95% CI 1.41-1.52), whereas the live attenuated influenza vaccine was associated with a lower incidence of AEIs (RI 0.79, 95% CI 0.73-0.83). No effect of vaccination setting on the incidence of AEIs was observed.ConclusionsRoutine sentinel network data offer an opportunity to make comparisons between safety profiles of different vaccines. Evidence that supports the safety of newer types of vaccines may be reassuring for patients and could help improve uptake in the future.

Seroresponse to Inactivated and Recombinant Influenza Vaccines Among Maintenance Hemodialysis Patients

High-dose influenza vaccine provides better protection against influenza infection in older adults than standard-dose vaccine. We compared vaccine seroresponse among hemodialysis patients over a period of 4 months after administration of high-dose trivalent inactivated (HD-IIV3), standard-dose quadrivalent inactivated (SD-IIV4), or quadrivalent recombinant quadrivalent (RIV4) influenza vaccine. Prospective observational study. Patients at 4 hemodialysis clinics who received influenza vaccine. Type of influenza vaccine. Hemagglutination inhibition (HI) titers were measured at baseline and at 1, 2, 3, and 4 months after vaccination. The primary outcome was seroprotection rates at HI titers of at least 1:40 and at least 1:160 (antibody levels providing protection from infection in approximately 50% and 95% of immunocompetent individuals, respectively) at 1, 2, 3, and 4 months after vaccination. We calculated geometric mean titer as well as seroprotection and seroconversion rates. Adjusted generalized linear models with additional trend analyses were performed to evaluate the association between vaccine type and outcomes. 254 hemodialysis patients were vaccinated against influenza with HD-IIV3 (n= 141), SD-IIV4 (n= 36), or RIV4 (n= 77). A robust initial seroresponse to influenza A strains was observed after all 3 vaccines. Geometric mean titer and seroprotection (HI titer≥1:160) rates against influenza A strains were higher and more sustained with HD-IIV3 than SD-IIV4 or RIV4. More than 80% of patients vaccinated with HD-IIV3 were seroprotected (HI titer≥1:160) at month 4 (P< 0.001), whereas, among patients vaccinated with SD-IIV4 or RIV4, seroprotection rates were similar to those at baseline. Seroprotection rates were lower against B strains for all vaccines. Because of the use of observational data, bias from unmeasured confounders may exist. Some age subgroups were small in number. Clinical outcome data were not available. Hemodialysis patients exhibited high seroprotection rates after all 3 influenza vaccines. The seroresponse waned more slowly with HD-IIV3 compared with SD-IIV4 and RIV4 vaccines.