Prevaccination antibody titers can estimate the immune response to influenza vaccine in a rural community-dwelling elderly population

Influenza and its complications are related to increased morbidity and mortality in elderly persons. Influenza vaccination is an important strategy to minimize the excess morbidity and mortality caused by influenza infection. Influenza epidemics start in November and continue to March in the next year, but it is not clear if the immunization-induced antibody titer lasts throughout the influenza season. One hundred eighty-two rural community-dwelling elderly persons older than 61 years were immunized with one dose of influenza vaccine in the 2005-2006 influenza season, and the antibody response after vaccination was investigated. Both the antibody titers and seroprotection rates were significantly higher four weeks after the vaccination but decreased markedly at 22 weeks after the vaccination. Analysis of the factors affecting the antibody response showed that those who have a low antibody titer before vaccination (‘seronegative’) do not acquire enough antibody with one dose of influenza vaccine. Neither age nor vaccination in the previous year was related to the antibody response after vaccination. These findings suggest that future clinical trials should be performed to determine if a second booster vaccination maintains the titer.     

Willingness of healthcare workers to accept voluntary stockpiled H5N1 vaccine in advance of pandemic activity

Healthcare workers may be at risk during the next influenza pandemic. Priming with stockpiled vaccine may protect staff and reduce nosocomial transmission. Despite campaigns to increase seasonal influenza vaccine coverage, uptake among healthcare workers is generally low; creating uncertainty whether they would participate in pre-pandemic vaccine programmes. We conducted a cross-sectional questionnaire survey of healthcare workers in a UK hospital during, and 6 months after, a period of media reporting of an H5N1 outbreak at a commercial UK poultry farm. A total of 520 questionnaires were returned, representing 20% of frontline workforce. More respondents indicated willingness to accept stockpiled H5N1 vaccine during the period of media attention than after (166/262, 63.4% vs. 134/258, 51.9%; p = 0.009). Following multivariate analysis, factors associated with willingness to accept H5N1 vaccine included: previous seasonal vaccine (OR 6.2, 95% CI 3.0–12.8, p < 0.0001), awareness of occupational seasonal vaccine campaigns (OR 2.2, 95% CI 1.4–3.5, p = 0.001), belief that seasonal vaccine benefits themselves (OR 2.5, 95% CI 1.6–4.0, p < 0.0001) or the hospital (OR 3.6, 95% CI 2.3–5.8, p < 0.0001), belief that pandemic risk is high/moderate (OR 14.1, 95% CI 7.6–26.1, p < 0.0001) and would threaten healthcare workers (OR 2.9, 95% CI 1.8–4.5, p < 0.0001). Those who would not accept vaccine (220 respondents, 42.7%) if offered before the pandemic do not perceive pandemic influenza as a serious threat, and have concerns regarding vaccine safety. A majority of healthcare workers are amenable to accept stockpiled H5N1 vaccine if offered in advance of pandemic activity.     

Legal considerations surrounding mandatory influenza vaccination for healthcare workers in the United States

Recent years have brought increased focus on the desirability of vaccinating more healthcare workers against influenza. The concern that novel 2009 H1N1 influenza A would spark a particularly severe influenza season in 2009–2010 spurred several institutions and one state to institute mandatory vaccination policies for healthcare workers, and several new mandates have been introduced since then. Some healthcare workers, however, have voiced objections in the media and in legal proceedings. This paper reviews the characteristics of influenza and how it is transmitted in the healthcare setting; surveys possible constitutional, administrative, and common law arguments against mandates; assesses the viability of those arguments; and identifies potential new legal strategies to support influenza vaccine mandates. It is intended to assist those involved in the regulation and administration of public and private healthcare institutions who may be considering approaches to mandates but have concerns about legal challenges.     

Effectiveness of seasonal influenza vaccination in healthcare workers: a systematic review

Vaccination is considered a key measure to protect vulnerable groups against influenza infection. The objectives of this review are to determine the effect of influenza vaccinations in reducing laboratory-confirmed influenza infections, influenza-like illnesses (ILIs), working days lost among vaccinated HCWs, and associated adverse effects after vaccination. Twenty-two healthcare-related databases and internet resources, as well as reference lists, and the bibliographies of all of the retrieved articles were examined. All randomized controlled trials (RCTs) comparing the effectiveness of any kind of influenza vaccine among all groups of HCWs with a placebo/vaccine other than the influenza vaccine/no intervention were included in the review. Only three RCTs matched the inclusion criteria. There is a limited amount of evidence suggesting that receiving influenza vaccination reduces laboratory-confirmed influenza infections in HCWs. No evidence can be found of influenza vaccinations significantly reducing the incidence of influenza, number of ILI episodes, days with ILI symptoms, or amount of sick leave taken among vaccinated HCWs. There is insufficient data to assess the adverse effects after vaccination. There is no definitive conclusion on the effectiveness of influenza vaccinations in HCWs because of the limited number of related trials. Further research is necessary to evaluate whether annual vaccination is a key measure to protect HCWs against influenza infection and thus increase their confidence in the vaccine. In the mean time, the direction of promoting influenza vaccination to HCWs can be shifted from staff protection to patient protection, with accurate information to address concerns and misconceptions.     

Motivating factors for high rates of influenza vaccination among healthcare workers

Background

Recent guidance from related regulatory agencies and medical societies supports mandatory vaccination of healthcare workers (HCW) against influenza. At St. Jude Children's Research Hospital, a pediatric oncology referral center, more than 90% of HCWs receive vaccine each year without a policy mandating immunization. Factors associated with HCW uptake of influenza vaccines have not previously been evaluated in a high compliance rate setting.

Methods

A structured, anonymous, electronic questionnaire was distributed in August 2010 to employees (HCW and non-HCW). Demographics, prior receipt of influenza vaccines, reasons for acceptance or refusal of seasonal and 2009 H1N1 pandemic vaccine, and attitudes on mandatory vaccination were assessed.

Results

95.0% of 925 HCWs and 63.1% of all 3227 qualifying employees responded to the survey. 93.8% and 75.2% of HCW reported receiving seasonal and 2009 H1N1 influenza vaccines, respectively, in the 2009-2010 season. Benefits to self and/or patients were cited as the most frequent reasons for accepting seasonal (83.5% and 78.3%, respectively) and 2009 H1N1 (85.9% and 81.1%, respectively) vaccination. 36.6% of HCWs opposed mandating influenza vaccination; 88.2% and 59.9% of whom reported receiving the seasonal and 2009 H1N1 influenza vaccines, respectively. Violation of freedom of choice and personal autonomy were the most frequently reported reasons for opposition.

Conclusion

In this cohort of HCWs with a high influenza vaccination rate, realistic assessments of the potential benefits of vaccination appear to have driven the choice to accept immunization. Despite this, mandating vaccination was viewed unfavorably by a significant minority of vaccinated individuals. Employee concerns over autonomy should be addressed as institutions transition to mandatory vaccination policies.     

Acceptance of a vaccine against pandemic influenza A (H1N1) virus amongst healthcare workers in Beijing, China

Due to the advent of the new influenza A (H1N1) strain in 2009, many countries introduced mass immunization programs. Healthcare workers (HCWs) were amongst the key groups targeted for the vaccine in these programs. However, experience with the seasonal influenza vaccine has shown that there are multiple barriers related to the attitudes and perceptions of the population which influence uptake. The aim of this study was to determine pandemic influenza A (H1N1) vaccination rate amongst a group of Chinese HCWs and the associated factors around acceptance.A cross-sectional investigation of HCWs (doctors, nurses and technicians) from 19 hospitals in Beijing, China was conducted in January 2010. The main outcome measures were awareness, risk perception of H1N1, preventive measures and uptake of H1N1 vaccination during the pandemic. A total of 1657 HCWs completed the survey. A quarter of the participants reported receiving the pandemic influenza A (H1N1) vaccine. Occupation (being a doctor), receiving seasonal flu vaccine and believing in the effectiveness of the vaccine were all strongly associated with accepting the pandemic influenza A (H1N1) vaccine. Over a thousand participants (61%, 1008/1657) agreed that they were ‘concerned about the side effects of the swine flu vaccine’, while 758 (46%) were ‘concerned that the vaccine had not been tested adequately’.While studies reported high rates of willingness to receive the vaccine, in reality these did not transpire. Aside from promoting seasonal flu vaccination, authorities need to start educational campaigns much earlier in a pandemic. Programs that are simultaneously launched with the introduction of the vaccine will not be as successful, as those which have built momentum alongside the pandemic.     

Determination of factors required to increase uptake of influenza vaccination among hospital-based healthcare workers

A questionnaire study was performed in all eight University Medical Centers in The Netherlands to determine the predictors of influenza vaccination compliance in hospital-based healthcare workers (HCWs). Demographical, behavioural and organisational determinants were assessed based on behavioural and implementation models. Multivariable regression analysis was applied to assess the independent predictors for influenza vaccine uptake. Age >40 years, the presence of a chronic illness, awareness of personal risk and awareness of risk of infecting patients, trust in the effectiveness of the vaccine to reduce the risk of infecting patients, the HCWs' duty to do no harm and their duty to ensure continuity of care, finding vaccination useful despite the constant flow of visitors and having knowledge of the Health Council's advice, social influence and convenient time for vaccination were all independently associated with vaccine uptake. The accuracy of the prediction model was very high (area under the receiver operating curve: 0.95). Intervention programmes to increase influenza vaccine uptake among HCWs should target the relevant determinants identified in this study.     

Effect of the 2020/21 season influenza vaccine on SARS-CoV-2 infection in a cohort of Italian healthcare workers

ObjectivesHealthcare workers (HCWs) are a priority group for seasonal influenza vaccination (SIV). The 2020/21 SIV campaign was conducted during the second wave of the COVID-19 pandemic. Vaccines, including SIV, may exert non-specific protective effects on other infectious diseases which may be ascribable to the concept of trained immunity. The aim of this study was to explore the association between 2020/21 SIV and SARS-CoV-2 positivity in a cohort of Italian HCWs.MethodsIn this observational study, a cohort of HCWs employed by a large (ca 5000 employees) referral tertiary acute-care university hospital was followed up retrospectively until the start of the COVID-19 vaccination campaign. The independent variable of interest was the 2020/21 SIV uptake. Both egg-based and cell culture-derived quadrivalent SIVs were available. The study outcome was the incidence of new SARS-CoV-2 infections, as determined by RT-PCR. Multivariable Cox regression was applied in order to discern the association of interest.ResultsThe final cohort consisted of 2561 HCWs who underwent ≥1 RT-PCR test and accounted for a total of 94,445 person-days of observation. SIV uptake was 35.6%. During the study period, a total of 290 new SARS-CoV-2 infections occurred. The incidence of new SARS-CoV-2 was 1.62 (95% CI: 1.22–2.10) and 3.91 (95% CI: 3.43–4.45) per 1000 person-days in vaccinated and non-vaccinated HCWs, respectively, with an adjusted non-proportional hazard ratio of 0.37 (95% CI: 0.22–0.62). E-values suggested that unmeasured confounding was unlikely to explain the association.ConclusionsA lower risk of SARS-CoV-2 infection was observed among SIV recipients.     

The impact of personal coaching on influenza vaccination among healthcare workers before and during COVID-19 pandemic

BackgroundWithout the implementation of mandatory vaccination, it was difficult to increase the influenza vaccination rate among healthcare workers. We described the strategy of personal coaching and assess its impact in increasing the influenza vaccination rate among healthcare workers in Hong Kong.MethodsPersonal coaching of individual staff led by the infection control officer (ICO) and senior nursing officer (SNO) from infection control team could overcome barriers and promote on-site vaccination. The influenza vaccination rates among different categories of staff in 2016/2017 (year 1, baseline), 2017/2018 (year 2, promotion using social media), and 2018/2019 to 2020/2021 (year 3–5, promotion using personal coaching) were analysed in a healthcare region with 8490 ± 206 staff during the study period.ResultsWith the implementation of personal coaching, the influenza vaccination rates increased significantly among medical (65.0% vs 57.0%, p = 0.048), nursing (30.6% vs 21.1%, p < 0.001), allied health (37.0% vs 27.4%, p < 0.001), care-related supporting staff (37.7% vs 27.3%, p < 0.001), and non-professional staff (27.3% vs 22.3%, p < 0.001) in year 3 compared with year 2, and also significantly increased among all staff in year 4 (38.0% vs 34.7%, p < 0.001) and year 5 (45.2% vs 38.0%, p < 0.001) when compared with the preceding year. The increase in vaccination rate was not apparent with social media promotion alone (26.4%, year 2 vs 25.6%, year 1, p = 0.305).ConclusionPersonal coaching led by ICO and SNO significantly increased the vaccination rates among healthcare workers in 3 consecutive years. This model could be promulgated to unit heads to establish a hospital culture conducive to vaccination.     

Examining the views of key stakeholders regarding the provision of occupational influenza vaccination for healthcare workers in Australia

Annual vaccination of hospital healthcare workers (HCWs) may be an effective measure to reduce the transmission of healthcare associated influenza. However, vaccine coverage rates among HCWs in most public Australian hospitals are below satisfactory for a number of reasons. This study aimed to examine the opinions of key health stakeholders on current issues regarding HCW influenza vaccination.     

Reflections on the influenza vaccination of healthcare workers

Despite all that is known about the dangers of nosocomial transmission of influenza to the vulnerable patient populations in our healthcare facilities, and the benefits of the influenza vaccination, the low rates of influenza vaccination among healthcare workers (HCWs) internationally shows no sign of significant improvement. With the current voluntary 'opt-in' programmes clearly failing to adequately address this issue, the time has undoubtedly come for a new approach to vaccination to be implemented. Two different approaches to vaccination delivery have been suggested to rectify this situation, mandatory vaccination and 'opt-out' declination forms. It is suggested, however, that these two approaches are inadequate when used by themselves. In order to protect the most vulnerable patients in our healthcare facilities as best we can from serious harm or death caused by nosocomial transmission of influenza, while at the same time respecting HCWs autonomy, and in many jurisdictions, the related legal right to refuse medical treatment, it is recommended that 'op-out' declination forms should be used in conjunction with restricted mandatory vaccination. This 'combined' approach would allow any HCW to refuse the influenza vaccination, but would make the influenza vaccination a mandatory requirement for working in areas where the most vulnerable patients are cared for. Those HCWs not willing to be vaccinated should be required to work in other areas of healthcare.     

Achieving optimal influenza vaccination rates: a survey-based study of healthcare workers in an urban hospital

In the USA, more than 36 000 deaths and 114 000 hospitalisations result from the influenza virus annually. Healthcare workers have been identified as a key source of influenza outbreaks. Despite Centers for Disease Control and Prevention recommendations to vaccinate all healthcare workers, the rate remains low. A survey-based investigation of influenza vaccination rates and related factors was carried out in an urban community teaching medical centre. A total of 570 surveys revealed a 56.5% influenza vaccination rate among participants. Participants who received the vaccine had a significantly higher mean influenza knowledge score compared to those who did not receive the vaccine (P=0.003). Also, a relationship was identified between those who received the vaccine and the perception that the purpose of the vaccine is to prevent patients from being exposed to influenza (P=0.001). Lastly, hospital departments in which managers actively encouraged and facilitated vaccination had higher rates in general.     

Exploring vaccination coverage and attitudes of health care workers towards influenza vaccine in Cyprus

Seasonal influenza is a major public health problem. Nosocomial influenza is particularly concerning as it may affect patients at high risk for complications. Unvaccinated health care workers (HCWs) are an important source of nosocomial influenza and therefore a priority target group for vaccination. Despite the fact that some European countries have high coverage rates such as UK (76.8% in season 2020/21), others continue to have low coverage rates for influenza vaccines. This study aims to estimate vaccination coverage in HCWs in Cyprus, an island country located in the Eastern Mediterranean region and describe their attitudes towards influenza vaccination.MethodsThis is a questionnaire based, nation-wide study assessing flu vaccination coverage in 2019–2020 and attitudes related to vaccination acceptance, of 962 HCWs in both public and private health care facilities. Multivariable logistic regression was used to investigate factors associated with flu vaccination status.ResultsFlu vaccination coverage was estimated as 31.8%. The top two reasons for getting vaccinated were to protect their family (81.4%) and themselves (77.4%). The top two reasons for not getting immunised, besides “no particular reason” (25.7%), included disbelief for vaccine effectiveness (21.5%) and safety (29.3%). The regression model showed that doctors compared to nurses had 10 times the odds of being vaccinated. Other factors positively associated with flu vaccination were encouragement by the supervisor, having sufficient knowledge on flu and flu vaccination and easy access to vaccination. A percentage of 54.8% of participants stated that COVID-19 pandemic strongly or somewhat influenced their decision to get vaccinated.ConclusionFlu vaccination coverage in HCWs in Cyprus is rather low, similar to some other European countries. Barriers and facilitators in this study can be considered in strategies to increase flu vaccination uptake. Such questionnaire-based surveys should be repeated in order to evaluate effectiveness of targeted vaccination campaigns.     

Randomized trial of HPV4 vaccine assessing the response to HPV4 vaccine in two schedules among Peruvian female sex workers

Two hundred female sex workers (FSWs) in Lima, Peru were randomized to receive HPV4 vaccine in the standard (0, 2, 6 months) or a modified schedule (0, 3, 6 months). One hundred and eighty four (92%) participants completed 3 doses of vaccine. Baseline seropositive rates were 58% for HPV6, 22.5% for HPV11, 41.5% for HPV16, and 13% for HPV18. The final geometric mean antibody titer (GMT) following vaccination was significantly greater for women who were seropositive at baseline compared to seronegative women: HPV6 (GMT ratio=2.3, p<0.01), HPV11 (GMT ratio=2.7, p<0.01), HPV16 (GMT ratio=1.3, p=0.04), and HPV18 (GMT ratio=2.4, p<0.01). Antibody titers in the modified schedule were not inferior to those in the standard schedule, suggesting the modified schedule may be paired with required STD visits. Although all women benefit from vaccination, administration at a younger age and before sexual debut is needed to achieve maximum protection from vaccine.     

Serological response to trivalent inactive influenza vaccine in HIV-infected children with different immunologic status

Influenza vaccination is usually recommended for HIV-infected children. One hundred and twenty seven HIV-infected and twenty-one HIV-uninfected children aged ≥6 months to <18 years, all of whom were naïve to influenza vaccine, were enrolled to receive an influenza Trivalent Inactivated Vaccine (TIV). In the HIV group, the post-vaccination immune response (geometric mean titer, seroconversion and seroprotection rates) correlated with their immunological status before vaccination. The HIV-infected children with no immunosuppression had comparable serological response to HIV-uninfected children. For moderately and severely immunosuppressed HIV groups, two doses of TIV resulted in greater serological responses and should be recommended in these groups.     

Antibody response to influenza immunization in coronary artery disease patients: A controlled trial

Safety of and humoral immune response to the anti-influenza vaccine in coronary artery disease (CAD) patients were evaluated. The trivalent vaccine was administered to 137 eligible CAD patients and 67 age- and sex-matched healthy individuals. Antibody (Ab) titers were measured before and 1 month after vaccination. CAD and HC groups were not significantly different in serologic response and magnitude of change in antibody titers against each of the vaccine antigens. In multivariate analyses, regular exercise and using multivitamin supplements were independently associated with better antibody response among CAD patients. There were no major cardiac or general adverse effects. Influenza vaccine was found safe in CAD patients and antibody responses were similar to HCs.     

COVID-19 vaccine uptake and its associated factors among Palestinian healthcare workers: Expectations beaten by reality

BackgroundIn response to this extraordinary outbreak, many countries and companies rush to develop an effective vaccine, authorize, and deliver it to all people across the world. Despite these extensive efforts, curbing this pandemic relies highly upon vaccination coverage. This study aimed to determine SARS-COV-2 vaccine uptake among Palestinian healthcare workers, the factors that influence vaccination uptake, and the motivators and barriers to vaccination.MethodsA cross-sectional study was conducted using an online anonymous self-administered questionnaire during April and May 2021, after the Palestinian Ministry of Health launched the COVID-19 vaccination campaign.The questionnaire collected socio-demographic characteristics, vaccination attitude and vaccination uptake status, and motivators and barriers towards vaccination. In addition, multivariate logistic regression was performed to identify the influencing factors of vaccination uptake.ResultsThe study included 1018 participants from different professions, including 560 (55.0%) females. Of the participants, 677 (66.5%; 95% CI: 63.5–69.4%) received the vaccine. Higher uptake was observed among males (aOR = 1.5; 95 %CI: 1.1–2.1), single HCWs (aOR = 1.3; 95 %CI: 1.1–1.8), HCWs working in the non-governmental sector (aOR = 1.6; 95 %CI: 1.2–2.4), higher monthly income (aOR = 1.9; 95 %CI: 1.4–2.8) and smoking (aOR = 1.5; 95 %CI: 1.1–3.5). The lower level of negative vaccination attitudes predicted higher intake; mistrust of vaccine belief (aOR = 1.6; 95 %CI: 1.4–1.7) and worries over unforeseen future effects (aOR = 1.2; 95 %CI: 1.1–1.3).ConclusionIn conclusion, the COVID-19 vaccination uptake was comparable to other studies worldwide but still needs to be improved, especially in the context of this ongoing global pandemic. It is imperative to invest resources to promote vaccination uptake and target all the vaccine misconceptions and fears.     

Knowledge and attitude of Kenyan healthcare workers towards pandemic influenza disease and vaccination: 9 years after the last influenza pandemic

BackgroundHealthcare workers (HCWs) are at high risk of exposure and transmission of infectious respiratory pathogens like influenza. Despite the potential benefits, safety and efficacy of influenza vaccination, vaccines are still underutilized in Africa, including among HCWs.MethodFrom May-June 2018, we conducted a cross-sectional, self-administered, written survey among HCWs from seven counties in Kenya and assessed their knowledge attitudes and perceptions towards pandemic influenza disease and vaccination. Using regression models, we assessed factors that were associated with the HCW’s knowledge of pandemic influenza and vaccination.ResultsA total of 2,035 HCWs, representing 49% of the targeted respondents from 35 health facilities, completed the question. Sixty eight percent of the HCWs had ever heard of pandemic influenza, and 80.0% of these were willing to receive pandemic influenza vaccine if it was available. On average, Kenyan HCWs correctly answered 55.0% (95% CI 54.0–55.9) of the questions about pandemic influenza and vaccination. Physicians (65.6%, 95% CI 62.5–68.7) and pharmacists (61.7%, 95% CI 57.9–65.5) scored higher compared to nurses (53.1%, 95% CI 51.7–54.5). HCWs with 5 or more years of work experience (55.8, 95% CI 54.5–57.0) had marginally higher knowledge scores compared to those with less experience (53.9%, 95% CI 52.5–55.3). Most participants who were willing to receive pandemic influenza vaccine did so to protect their relatives (88.7%) or patients (85.9%).ConclusionOur findings suggest moderate knowledge of pandemic influenza and vaccination by HCWs in Kenya, which varied by cadre and years of work experience. These findings highlight the need for continued in-service health education to increase the HCW’s awareness and knowledge of pandemic influenza to increase acceptance of influenza vaccination in the case of a pandemic.     

Impact of early life exposure to ionizing radiation on influenza vaccine response in an elderly Japanese cohort

The objective of this study was to evaluate effects of whole body radiation exposure early in life on influenza vaccination immune responses much later in life. A total of 292 volunteers recruited from the cohort members of ongoing Adult Health Study (AHS) of Japanese atomic bomb (A-bomb) survivors completed this observational study spanning two influenza seasons (2011–2012 and 2012–2013). Peripheral blood samples were collected prior to and three weeks after vaccination. Serum hemagglutination inhibition (HAI) antibody titers were measured as well as concentrations of 25 cytokines and chemokines in culture supernatant from peripheral blood mononuclear cells, with and without in vitro stimulation with influenza vaccine. We found that influenza vaccination modestly enhanced serum HAI titers in this unique cohort of elderly subjects, with seroprotection ranging from 18 to 48% for specific antigen/season combinations. Twelve percent of subjects were seroprotected against all three vaccine antigens post-vaccination. Males were generally more likely to be seroprotected for one or more antigens post-vaccination, with no differences in vaccine responses based on age at vaccination or radiation exposure in early life. These results show that early life exposure to ionizing radiation does not prevent responses of elderly A-bomb survivors to seasonal influenza vaccine.