History Of Influenza Vaccination Research Articles

Impact of influenza vaccination history in the clinical course of older adults hospitalized with COVID-19

Background and purposeSome studies have shown that influenza vaccination is associated with a lower risk of SARS-CoV-2 infection; in patients with COVID-19 infection, admission to intensive care is reduced, with less need for mechanical ventilation, shorter hospital stays, and reduced mortality. This study aimed to determine if a history of annual influenza vaccination impacts the clinical course of SARS-CoV-2 infection during hospitalization. MethodsThis was an observational, prospective, cohort study of patients older than 65 admitted to the COVID-19 unit from January to June 2021. The history of influenza vaccination over the last 5 years was assessed in each patient during hospitalization. We measured the length of hospital stay, the need for admission to the intensive care unit (ICU), the patient's oxygen requirements, complications during hospitalization, and outcome (medical discharge or death). Patients with a history of vaccination against SARS-CoV-2 were not included. ResultsWe analyzed 125 patients, 50.4% (n=63) with history of influenza vaccination and 49.6% (n=62) without a history of influenza vaccination. In-hospital mortality was 44.8%, higher in the unvaccinated (54.8%) population (p=0.008). ICU admission was 27% higher in vaccinated (35%) patients (p=0.05). Patients without a history of influenza vaccination had a higher prevalence of cardiac (8% vs. 5%, p=0.04) and renal complications (29% vs. 13%, p=0.02). Patients with a history of vaccination had a greater need for invasive mechanical ventilation (25.4%, p=0.02). ConclusionIn this study, a history of influenza vaccination in older adults with SARS-CoV-2 infection was related to lower in-hospital mortality.

Effectiveness of Influenza Vaccination and Early Antiviral Treatment in Reducing Pneumonia Risk in Severe Influenza Cases.

Influenza vaccination may be effective in preventing influenza infection and may reduce the risk of influenza-associated pneumonia. The study aim was to evaluate the effect of influenza vaccination in preventing pneumonia when it failed to prevent influenza hospitalization. This was a case-control study comparing hospitalized cases of influenza with and without pneumonia in patients aged ≥18 years in 16 hospitals in Catalonia over 10 influenza seasons (2010-11 to 2019-20). Data on sociodemographic, virological characteristics, comorbidities, vaccination history, and antiviral treatment were collected and analysed. The crude odds ratio (OR) and adjusted OR (aOR) with the corresponding 95% confidence interval (CI) values were calculated. In total, 5080 patients hospitalized for severe influenza were included, 63.5% (3224/5080) of whom had pneumonia-mostly men (56.8%; 1830/3224) and mostly in the ≥75 age group (39.3%; 1267/3224)-and of whom 14.0% died (451/3224). Virus A and virus B accounted for 78.1% (2518/3224) and 21.9% (705/3224) of influenza types, respectively. Starting antiviral treatment ≤48 h after symptom onset (aOR = 0.69; 95%CI: 0.53-0.90) and a history of seasonal influenza vaccination (aOR = 0.85; 95%CI: 0.72-0.98) were protective factors in developing pneumonia. Adherence to seasonal influenza vaccination and starting antiviral treatment within 48 h of symptom onset can reduce pneumonia risk in severe influenza cases.

Willingness to receive and recommend hypothetical mpox vaccination and associated factors in Chinese adults: a community-based survey in Shenzhen, China

ObjectivesChina may face new threats to public health due to the increased risk of imported mpox (monkeypox) cases. However, research gaps exist in the acceptance of mpox vaccination and potential associated factors in the Chinese population. Study designWe conducted a cross-sectional study targeting community residents in Shenzhen, China, from August 5 to September 7 2022. MethodsA self-administered questionnaire was used to collect information about demographic and health characteristics, mpox-related perceptions, and attitudes towards mpox vaccination. Multivariable logistic regression models were applied to detect the factors associated with willingness to receive and recommend mpox vaccination. ResultsA total of 2293 community residents were included in the analyses (average age: 34.03, female: 72.6%). Among the participants, 76.9% were aware of mpox, 62.1% were aware of the global mpox outbreak, but only 53.6% had a high knowledge level of mpox. Males had a higher proportion of high knowledge (56.9% vs 52.3%, P＜0.05) and a lower proportion of high worry (30.2% vs 45.4%, P＜0.05) than females. Approximately 69.1% of the participants were willing to vaccinate against mpox, and 69.6% were willing to recommend mpox vaccination to people around them, in which no gender difference was found. The obstacle reported most among people hesitant to receive vaccination was concerning the safety and side-effects, whereas it changed to be concerning the suitability due to individual health differences among people hesitant to recommend mpox vaccines. Factors associated with the willingness to receive and recommend mpox vaccination included having a history of influenza vaccination, having a history of COVID-19 vaccination, being aware of the global mpox outbreak, having a high knowledge level of mpox, and having a high level of mpox-related worry. ConclusionsThis study identified a moderate willingness to receive and recommend mpox vaccination among Chinese adults. Without gender differences, willingness to receive and recommend mpox vaccination was significantly associated with mpox-related perceptions, such as awareness, knowledge, and worry. Authoritative and up-to-date information is needed to help the general population improve public confidence in mpox vaccines in China.

Influenza Vaccine Effectiveness Pre-pandemic Among Adults Hospitalized With Congestive Heart Failure or Chronic Obstructive Pulmonary Disease and Older Adults.

Data are limited on influenza vaccine effectiveness (VE) in the prevention of influenza-related hospitalizations in older adults and those with underlying high-risk comorbidities. We conducted a prospective, test-negative, case-control study at 2 US hospitals from October 2018-March 2020 among adults aged ≥50 years hospitalized with acute respiratory illnesses (ARIs) and adults ≥18 years admitted with congestive heart failure (CHF) or chronic obstructive pulmonary disease (COPD) exacerbations. Adults were eligible if they resided in 1 of 8 counties in metropolitan Atlanta, Georgia. Nasopharyngeal and oropharyngeal swabs were tested using BioFire FilmArray (bioMérieux, Inc.) respiratory panel, and standard-of-care molecular results were included when available. Influenza vaccination history was determined from the Georgia vaccine registry and medical records. We used multivariable logistic regression to control for potential confounders and to determine 95% confidence intervals (CIs). Among 3090 eligible adults, 1562 (50.6%) were enrolled. Of the 1515 with influenza vaccination history available, 701 (46.2%) had received vaccination during that season. Influenza was identified in 37 (5.3%) vaccinated versus 78 (9.6%) unvaccinated participants. After adjustment for age, race/ethnicity, immunosuppression, month, and season, pooled VE for any influenza-related hospitalization in the eligible study population was 63.1% (95% CI, 43.8-75.8%). Adjusted VE against influenza-related hospitalization for ARI in adults ≥50 years was 55.9% (29.9-72.3%) and adjusted VE against influenza-related CHF/COPD exacerbation in adults ≥18 years was 80.3% (36.3-93.9%). Influenza vaccination was effective in preventing influenza-related hospitalizations in adults aged ≥50 years and those with CHF/COPD exacerbations during the 2018-2020 seasons.

Vaccine hesitancy and related factors among South African adults in 2021: unpacking uncertainty versus unwillingness.

Amidst widespread public health recommendations and availability of COVID-19 vaccinations, half of South African adults are vaccinated against COVID-19. This study investigated the socio-behavioral determinants of vaccine hesitancy in South Africa, where vaccine hesitancy was separated into unwilling ness and uncertainty to take a COVID-19 vaccine. Data was collected from a large-scale public survey during June-October 2021 that included online and telephonic surveys. Vaccination hesitancy was based on the question "When available, would you take the COVID 19 vaccine?," with responses categorized into those who were willing, unwilling, and uncertain about taking a COVID-19 vaccine. Multinomial regression examined the association between socio-behavioral variables and vaccine hesitancy. Overall, 73.8% reported they would definitely or probably take the vaccine, 16.4% were uncertain and 9.9% reported they probably or definitely would not (n = 16,988). Younger age, White and Colored population groups, no influenza vaccination history, previous vaccination refusal, knowing someone who experienced a serious vaccination side-effect, misperceptions about vaccine benefits, cultural or religious discouragement from taking a COVID-19 vaccination, lack of governmental confidence, concerns about side-effects, perceived lack of safety information, and lack of trust in the pharmaceutical industry and in the information from health care providers were all associated with higher odds of being uncertain and unwilling to take a COVID-19 vaccination. Strengths of association for unwillingness and uncertainty varied by the explanatory variables. Concern about effectiveness due to fast development was associated with uncertainty to take the vaccine but not with unwillingness. Concerns about side-effects had stronger associations with uncertainty than with unwillingness, while previous vaccine refusal, misperceptions of the protective benefits of vaccines, White population group, religious/cultural discouragement, and lack of trust in the pharmaceutical industry and health care providers' information had stronger associations with unwillingness than uncertainty. The determinants of COVID-19 vaccine hesitancy should be addressed in interventions to improve vaccine uptake. Public health interventions and health communication can be prioritized and tailored to the different forms of vaccination hesitancy.

The Influence of the COVID-19 Pandemic on Seasonal Influenza Vaccine Uptake Among Patients Visiting a University Hospital in Saudi Arabia.

Influenza vaccination is a subject of importance in Saudi Arabia. The study measured the uptake of annual influenza vaccination from 2019 to 2021 among patients attending outpatient clinic of a University Hospital. Materials and methods: A cross-sectional study design was used, and the questionnaire was administered by trained interviewers. Descriptive and inferential statistics were done using the Statistical Package for the Social Sciences (SPSS) version 21 (IBM, Armonk, New York). Results: The three-year annual influenza vaccine uptake for 2019-2021 was 19.7%, 11.4%, and 14.2%, respectively. In the year 2022, only 28.2% of the patients were offered influenza vaccines by their physicians, and among those offered, 49.6% showed vaccine acceptance. Higher vaccine acceptance was significantly associated with past episodes of influenza infection (p<0.001) and vaccination history before the COVID-19 pandemic (p<0.001). Lower acceptance of the influenza vaccine was observed during the pandemic (p<0.001) and lower uptake among those who were not offered influenza vaccines (p=0.02). No association was found between influenza vaccine acceptance and smoking status, chronic illness, history of COVID-19 infection, or living with those susceptible to influenza. Reasons for vaccine denial include an assumption of not being at risk, a lack of information about the vaccine, and a fear of side effects. The COVID-19 pandemic has had a detrimental effect on annual influenza vaccination. Efforts must be taken to increase influenza vaccination among vulnerable groups.

A cross-sectional study from Qatar on the effect of influenza vaccination on the severity of COVID-19.

To assess and compare the severity of corona virus disease 2019 (COVID-19) infection in patients with and without a history of influenza vaccination. In this cross-sectional study descriptive statistics were used to analyze COVID-19-related parameters, including demographics, comorbidities, and severity. Normally distributed data with mean, standard deviation, and 95% confidence interval (CI) were reported, while non-normally distributed data was presented with median and inter-quartile range. Categorical data was summarized using frequencies and percentages. Associations were assessed using Pearson Chi-square, Fisher Exact, t test, or Mann-Whitney U test. Univariate and multivariate logistic regression methods were used to evaluate the relationship between disease severity, clinical outcomes, influenza vaccination status, and other predictors. Significance was considered for p values < 0.05. Statistical analyses were done using SPSS V.27.0 (IBM Corp) and Epi Info (CDC) software. Between March 2020 and December 2020 before the availability of COVID-19 vaccination, 148,215 severe acute respiratory syndrome corona virus 2 positive patients were studied, with 3519 vaccinated against influenza, and 144,696 unvaccinated. After random sampling at 1:2 ratio, the final analysis included 3234 vaccinated and 5640 unvaccinated patients. The majority (95.4%) had mild or asymptomatic COVID-19, while 4.6% had severe or critical cases as defined by World Health Organization severity grading. Multivariate logistic regression analysis revealed that the vaccinated group had significantly less severe (adjusted odds ratio [OR] 0.683; 95% CI 0.513-0.911, P = .009) and critical (adjusted OR 0.345; 95% CI 0.145-0.822, P = .016) COVID-19 and were less likely to require oxygen therapy (adjusted OR 0.696; 95% CI 0.531-0.912, P = .009) after adjusting for confounders like age, gender and comorbidities. No significant differences in Intensive care unit admissions (adjusted OR 0.686; 95% CI 0.425-1.11, P = .122), mechanical ventilation (adjusted OR 0.631; 95% CI 0.308-1.295, P = .209) and mortality (adjusted OR 1.105; 95% CI 0.348-3.503, P = .866) were noted between the 2 groups. Influenza vaccination may significantly reduce the severity of COVID-19 but has no significant effect on intensive care unit admissions, mechanical ventilation and all- cause mortality.

Impacts of a COVID-19 Educational Video: Evaluation of the Influence of Race, Gender, Political Affiliation, Study Major, and Age on Vaccine Acceptance among University Students.

The World Health Organization (WHO) warns that vaccine hesitancy is an ongoing major global health threat. While vaccination against severe acute respiratory syndrome coronavirus (SARS-CoV-2) proves to be an effective strategy in protecting against the disease, vaccine hesitancy represents a major barrier to stopping the spread of the virus. Willingness for vaccination can be influenced by several factors, including education level and health literacy. Although several studies demonstrate the value of video educational programs in improving coronavirus disease 2019 (COVID-19) vaccine knowledge and acceptance, no studies to date have evaluated if race, gender, and other demographic factors impact the influence of an educational video on COVID-19 vaccine knowledge and hesitancy among university students in the United States (U.S.). This study was conducted to determine the impact of an educational video on U.S. university undergraduate students' COVID-19 vaccine perception and acceptance. It also aims to evaluate whether demographic factors affect the influence of the video. An online survey was used to measure perceived understanding and acceptance of COVID-19 vaccines before and after viewing a video regarding the effectiveness and safety of COVID-19 vaccinations. The impact of demographic factors on the Video Influence Score was analyzed. After viewing the video, respondents' (n = 285) perceived awareness and acceptance of COVID-19 vaccines significantly increased (p < 0.05). In addition, gender, political party affiliation, age, study major, and influenza vaccination history did not significantly impact the Video Influence Score (p > 0.05). However, African American/Black respondents (3.81 ± 4.24) were significantly more influenced by the video compared to respondents of other races (p < 0.05), such as White/Caucasian (1.91 ± 3.75), Hispanic/Latino (0.17 ± 3.67), Asian (0.29 ± 1.53), and Indigenous American (0.64 ± 2.52). This study suggests the potential impact of an educational video on COVID-19 vaccine perception and acceptance among university students. Despite limitations such as a modest survey response rate, this study provides valuable insight concerning the influential factors affecting vaccine acceptance in diverse student populations. Future studies are warranted to explore how student response to vaccine educational videos may vary depending on students' racial and cultural backgrounds. A targeted educational video to promote vaccine acceptance is a valuable tool for public health campaigns to combat vaccine hesitancy. The study also highlights the importance of tailoring interventions to specific demographic groups such as considering racial factors to maximize the impact of educational interventions on vaccine attitudes.

National prevalence and socioeconomic factors associated with the acceptance of COVID-19 vaccines in South Korea: a large-scale representative study in 2021.

Among the global efforts toward preventing the COVID-19 pandemic, vaccines are a pivotal factor in ending the pandemic. Thus, through a large-scale population-based study, we investigated the individual-, social-, and family-associated factors affecting the acceptance of COVID-19 vaccines in South Korea. Data were obtained from a nationwide representative study (Korea Community Health) conducted in 2021. To determine the individual-, social-, and family-associated variables for COVID-19 vaccination acceptance, we investigated data from 225,319 individuals. In the total sample (n=225,319), 184,529 COVID-19-vaccinated people and 40,790 non-vaccinated people were evaluated. The factors related to the acceptance of COVID-19 vaccination were significantly associated with the demographic factors, namely, older age group, female sex, and a history of influenza vaccination, as well as medical conditions such as diabetes, hypertension, and depression. Socioeconomic conditions influencing the acceptance of COVID-19 vaccination were significantly associated with low-income families and blue-collar workers. Health-related risk factors were high in the obese group. However, a noteworthy negative association was found between the acceptance of vaccination and smoking habits and alcohol consumption. Conversely, a positive association was observed between academic level and vaccination acceptance. Our findings suggest that old age, female sex, a history of influenza vaccination, medical conditions, such as diabetes, hypertension, and depression, low-income families, blue-collar workers, and health-related risk factors, such as obesity, were associated with the acceptance of COVID-19 vaccination. Additionally, a high academic level, absence of smoking habits, and non-current alcohol use were positively associated with vaccine acceptance.

Predictors of immune persistence induced by two-dose BBIBP-CorV vaccine in high-risk occupational population

BackgroundThe immune protection from infection may wane over time as neutralizing antibody levels decline. We aimed to develop a nomogram to predict long-term immune persistence induced by two-dose BBIBP-CorV vaccine and calculate the neutralizing antibody decline probability of individuals. MethodsIn the initial study, a total of 809 participants were recruited and randomly allocated (1:1:1) to vaccination group with three two-dose schedules on days 0 and 14, 0 and 21, or 0 and 28. The participants with neutralizing antibody titers of 16 or above on day 28 after the second dose were followed up at month 3, 6 and 10. Multivariable Cox proportional hazards regression model and nomogram model were used to identify predictors associated with maintaining of neutralizing antibody levels during 10 months after the second dose. ResultsA total of 744 participants followed up at day 28 after the second dose. The participants with age ≥ 50 (aHR = 3.556, 95 %CI: 1.141–4.884, P = 0.028) were associated with a high risk of response loss (titers < 16). The participants who were in 0–28 d group (aHR = 0.403, 95 %CI: 0.177–0.919, P = 0.031), had an influenza vaccination history (aHR = 0.468, 95 %CI: 0.267–0.921, P = 0.033) or were female (aHR = 0.542, 95 %CI: 0.269–0.935, P = 0.035) tended to maintain immune persistence during 10 months after the second dose. The nomogram was constructed and showed moderate discrimination[C-index:0.711 (95 %CI: 0.652–0.770); AUC: 0.731 (95 %CI: 0.663–0.792)] and good calibration. ConclusionsFrom 28 days to 10 months after receipt of the second dose of the BBIBP-CorV vaccine, neutralizing antibody levels were substantially decreased, especially among men, among persons 50 years of age or older, among persons with the 0–14 d group, and among persons without history of influenza vaccination.Trial registration: Chinese Clinical Trial Registry, ChiCTR2100041705, ChiCTR2100041706.

Does Vaccine Confidence Mediate the Relationship between Vaccine Literacy and Influenza Vaccination? Exploring Determinants of Vaccination among Staff Members of Nursing Homes in Tuscany, Italy, during the COVID-19 Pandemic.

Low coverage of influenza vaccination in nursing home (NH) staff may be attributed to factors such as vaccine confidence (VC) and vaccine literacy (VL). Our study aimed to evaluate the role of VL and VC in predicting the intention to get the influenza vaccine in a sample of employees of NHs in Tuscany, Italy. Data from staff members in Tuscany were collected using an online questionnaire that examined influenza vaccination history, intentions, demographic information, health status, and VL. Statistical analyses explored the relationships between VC, VL, and vaccination intentions. The study included 1794 respondents, (86.3%) and assistants/aides (58.1%), with a median age of 46 years. The intention to get vaccinated was significantly higher among those with health risk conditions, and there was a positive association between VC and VL, specifically its interactive/critical component. The mediation analysis showed that VC completely mediated the relationship between VL and the intention to get vaccinated, with significant effects observed in different subgroups. VC is a key factor that mediates the effect of VL on vaccine intention. These results suggest that interventions aimed at improving VL alone may not be sufficient to increase vaccine uptake unless VC is also addressed.

Belarusian Healthcare Professionals' Views on Monkeypox and Vaccine Hesitancy.

Despite the low transmission risk of Monkeypox (mpox) in Belarus, this study is vital as it contributes to our understanding of vaccine hesitancy among healthcare professionals (HCPs). It aims to assess vaccination perceptions and evaluate the willingness to pay for the vaccine among Belarusian HCPs, thereby enhancing pandemic preparedness. in October 2022, a cross-sectional survey-based study was conducted among Belarusian HCPs using a self-administered questionnaire (SAQ). Invitations were disseminated via social media platforms using a snowball sampling method. The SAQ encompassed various categories, including sociodemographic details, medical history, sources of mpox information, perceived and factual mpox knowledge, and perceptions of the mpox vaccine according to the health belief model (HBM), mpox vaccine acceptance and willingness to pay (WTP). while a large proportion of respondents had good knowledge of mpox epidemiology and its clinical manifestations, their awareness of available vaccines and treatment options was limited. Consequently, a significant correlation was found between the history of influenza vaccination and mpox-related knowledge. Furthermore, the study showed that just over half of the participants (51.4%) were willing to receive the mpox vaccine if offered for free, safely, and effectively, with their decision largely influenced by perceived benefits (Spearman's rho = 0.451) and cues to action (Spearman's rho = 0.349). However, a considerable degree of hesitancy (30.6%) and resistance (18.1%) towards the mpox vaccine was observed, underscoring the need for targeted interventions to address these issues. this study highlights a significant knowledge gap among Belarusian HCPs about mpox vaccines and treatments, despite a general awareness of the disease's epidemiology and symptoms, and it underscores the need for targeted interventions to enhance mpox knowledge and vaccine acceptance.

Immunogenicity and safety of quadrivalent influenza vaccine among young and older adults in Tianjin, China: implication of immunosenescence as a risk factor

BackgroundOlder adults are more vulnerable to seasonal influenza than younger adults. The immune responses of older persons to the influenza vaccine are usually poorer than those of young individuals, which is hypothesized due to immunosenescence. We conducted a study to evaluate the immunogenicity and safety of a quadrivalent inactivated influenza vaccine (IIV4) in a total of 167 young (< 65 years, n = 79) and older (≥ 65 years, n = 88) adults from October 2021 to March 2022 in Tianjin, China. A single dose was administered to all participants. Blood samples were collected and strain-specific hemagglutination inhibition (HAI) antibody titers were measured before and 21 to 28 days after vaccination. Safety information was also collected for 28 days and 6 months after vaccination. Differences in immunogenicity and safety were compared between young and old age groups, and multivariate logistic regression was used to estimate the effect of age and other factors on HAI antibody responses.ResultsOverall, geometric mean titers (GMTs) against all four vaccine strains in older adults were lower than those in the young, whereas the seroconversion rates (SCRs) were similar. Multivariate logistic regression analysis showed that age, influenza vaccination history, and pre-vaccination HAI titers were independent factors affecting SCRs and seroprotection rates (SCRs). Older age had significant negative impact on SCRs against H1N1 (OR, 0.971; 95% CI: 0.944–0.999; P = 0.042) and B/Victoria (OR, 0.964; 95% CI: 0.937–0.992; P = 0.011). In addition, there was a significant negative correlation between chronological age (years) and post-vaccination HAI titers against H1N1 (rho = -0.2298, P < 0.0001), B/Victoria (rho = -0.2235, P = 0.0037), and B/Yamagata (rho = -0.3689, P < 0.0001). All adverse events were mild (grade 1 or grade 2) that occurred within 28 days after vaccination, and no serious adverse event was observed.ConclusionsIIV4 is immunogenic and well-tolerated in young and older adults living in Tianjin, China. Our findings also indicate that age is an independent factor associated with poorer humoral immune responses to IIV4.

Association of influenza vaccination or influenza virus infection history with subsequent infection risk among children: The Japan Environment and Children's Study (JECS)

We measured the association between history of influenza vaccination by age 2 years and influenza virus (IFV) infection at ages 3 and 4 years by relative risk reduction. We also examined the association between history of IFV infection by age 2 years and recurrent IFV infection at age 3 years. This study included 73,666 children from a large Japanese birth cohort. Among children vaccinated never, once or twice when aged under 2 years, 16.0%, 10.8% and 11.3%, respectively, had been infected with IFV by age 3 years, and 19.2%, 14.5% and 16.0%, respectively, by age 4 years. Compared with no history of influenza vaccination, vaccination at ages 1 and/or 2 years reduced the risk of IFV infection at age 3 by 30%–32% and at age 4 by 17%–24%. The relative risk of recurrent IFV infection at ages 3 and 4 years increased in proportion to the number of prior infections by age 2. One-season-prior influenza vaccination history reduced the IFV infection risk at age 3 years by 25%–42%. Influenza vaccination most effectively protected children at age 3 who lacked older sibling(s) and did not attend nursery school. One-season-prior IFV infection increased the relative risk of recurrent infection at age 3 years (1.72–3.33). In conclusion, influenza vaccination-induced protection may partly extend to the next season. Owing to the relative risk reduction by influenza vaccination and the increased relative risk of IFV infection from prior-season infection, annual influenza vaccination is recommended.

Determinants of influenza and pneumococcal vaccine uptake among preschool children in Singapore.

Young children are at increased risk of severe illness from influenza and pneumococcal infections. The World Health Organization (WHO) recommends vaccination with influenza and pneumococcal conjugate vaccine (PCV). However, in Singapore, vaccine uptake remains suboptimal relative to other routine childhood immunisations. Limited information exists regarding determinants of influenza and pneumococcal vaccine uptake in children. We estimated vaccine uptake and investigated factors associated with influenza and pneumococcal vaccination status by age group using data from a cohort study on acute respiratory infections in children attending preschools in Singapore. We recruited children aged two to six years at 24 participating preschools from June 2017 to July 2018. We determined the proportion of children immunised with influenza vaccine and PCV, and investigated socio-demographic factors associated with vaccine uptake using logistic regression models. Among 505 children, 77.5% were of Chinese ethnicity, and 53.1% were male. History of influenza vaccination was 27.5% of which 11.7% had been vaccinated within the past 12 months. In multivariable analyses, factors associated with influenza vaccine uptake were 'children living in landed property' (aOR = 2.25, 95% CI [1.07-4.67]) and 'history of hospitalisation due to cough' (aOR = 1.85, 95% CI [1.00-3.36]). Nearly three-quarters of participants (70.7% 95%CI: [66.6-74.5]) reported prior PCV vaccination. PCV uptake was higher for younger children. 'Higher parental education' (OR = 2.83, 95% CI [1.51,5.32]), 'household income' (OR = 1.26, 95% CI [1.08,1.48]) and 'smokers in household' (OR = 0.48, 95% CI [0.31,0.74]) were significantly associated with PCV uptake in univariable analyses. Only 'smokers in household' remained significantly associated with PCV uptake (aOR = 0.55, 95% CI [0.33,0.91]) in the adjusted model. Our results indicate that episodes of severe respiratory illness are a cue to influenza vaccination suggesting that doctors are more likely to recommend influenza vaccines to high-risk children. For PCV, our findings suggest overall greater awareness and education on the benefit of PCV vaccination is required.

Knowledge, attitudes, and practices associated with frequent influenza vaccination among healthcare personnel in Peru, 2016─2018

IntroductionDespite a government-subsidized vaccination program, healthcare personnel (HCP) influenza vaccination uptake remains low in Peru. Using three years of cross-sectional surveys and an additional five years of prior vaccination history of HCP in Peru, we explored HCP knowledge, attitudes, and practices (KAP) of influenza illness and its impact on vaccination frequency. MethodsIn 2016, the Estudio Vacuna de Influenza Peru (VIP) cohort was initiated in Lima, Peru, which collected information about HCP KAP and influenza vaccination history from 2011─2018. HCP were classified by their 8-year influenza vaccination history as never (0 years), infrequently (1─4 years), or frequently (5─8 years) vaccinated. Logistic regression models were used to describe KAP associated with frequent compared to infrequent influenza vaccination, adjusted for each HCP’s healthcare workplace, age, sex, preexisting medical conditions, occupation, and length of time providing direct patient care. ResultsFrom 2016─2018, 5131 HCP were recruited and 3120 fully enrolled in VIP; 2782 consistently reported influenza vaccination status and became our analytic sample. From 2011─2018, 14.3% of HCP never, 61.4% infrequently, and 24.4% frequently received influenza vaccines. Compared to HCP who were infrequently vaccinated, frequently vaccinated HCP were more likely to believe they were susceptible to influenza (adjusted odds ratio [aOR]:1.49, 95% confidence interval [CI]:1.22─1.82), perceived vaccination to be effective (aOR:1.92, 95%CI:1.59─2.32), were knowledgeable about influenza and vaccination (aOR:1.37, 95%CI:1.06─1.77), and believed vaccination had emotional benefits like reduced regret or anger if they became ill with influenza (aOR:1.96, 95%CI:1.60─2.42). HCP who reported vaccination barriers like not having time or a convenient place to receive vaccines had reduced odds of frequent vaccination (aOR:0.74, 95%CI:0.61─0.89) compared to those without reported barriers. ConclusionFew HCP frequently received influenza vaccines during an eight-year period. To increase HCP influenza vaccination in middle-income settings like Peru, campaigns could strengthen influenza risk perception, vaccine knowledge, and accessibility.

Assessment of the knowledge, attitudes, and behaviors of individuals presenting to family medicine polyclinics for COVID-19 and influenza vaccines: a study in a Turkish population

BACKGROUND: Vaccines are one of the most important weapons in protection against diseases, especially pandemics lacking available treatment. The objective of this study was to investigate the knowledge, attitudes, and behaviors of individuals presenting to family medicine polyclinics for COVID-19 and influenza vaccines.METHODS: The cross-sectional descriptive study comprised healthy individuals who presented to family medicine polyclinics in Ankara Training and Research Hospital, Ankara, Türkiye between 10 December 2020 and 31 January 2021. Data on participants’ knowledge and attitudes for COVID-19 and influenza vaccines were collected through questionnaire surveys. In total, 521 individuals aged older than 18 years were included in the study.RESULTS: If a COVID-19 vaccine were available, 34.4% (N.=179) of respondents would be vaccinated, and 35.3% (N.=184) of respondents would not consider vaccination. Of those considering COVID-19 vaccination, 55.3% (N.=99) of respondents deemed the vaccine an effective way of providing protection against the virus. Increased willingness to have the COVID-19 vaccine was associated with the following factors: considering the influenza vaccine an effective protection method (P<0.001), a history of influenza vaccination (P=0.003), and concern about COVID-19 related death rates (P=0.008).CONCLUSIONS: The most common reasons for COVID-19 vaccine hesitancy and refusal were fear of vaccine-related side effects and a lack of perceived research evidence on the vaccine. Having a positive view of the influenza vaccine had a positive impact on attitudes toward the COVID-19 vaccine.

Influenza vaccine uptake among children and older adults in China: a secondary analysis of a quasi-experimental study

BackgroundInfluenza vaccination is the key to prevent influenza-related disease, especially among high-risk populations. However, influenza vaccine uptake in China is low. This secondary analysis of a quasi-experimental trial aimed to understand factors associated with influenza vaccine uptake among children and older people stratified by funding context.MethodsA total of 225 children (aged 0.5-8 years) and 225 older people (aged 60 years or above) were recruited from three clinics (rural, suburban and urban) in Guangdong Province. Participants were allocated into two groups based on funding contexts: a self-paid group (N = 150, 75 children and 75 older adults) in which participants paid full price for their vaccination; and a subsidized group (N = 300, 150 children and 150 older adults) in which varying levels of financial support was provided. Univariate and multivariable logistic regressions were conducted stratified by funding contexts.ResultsOverall, 75.0% (225/300) of participants in the subsidized group and 36.7% (55/150) in the self-paid group got vaccinated. Older adults had lower vaccination rates than children in both funding groups, while both age groups showed much higher uptake in the subsidized group than in the self-paid group (aOR = 5.96, 95% CI: 3.77–9.42, p = 0.001). In the self-paid group, having prior influenza vaccination history of children (aOR:2.61, 95%CI: 1.06–6.42) or older people (aOR:4.76, 95%CI: 1.08–20.90) was associated with increased influenza vaccine uptake compared to those who had no prior vaccination experiences in the family. While in the subsidized group, participants who got married or lived with partners (aOR = 0.32, 0.10–0.98) had lower vaccination uptake than single ones. Trust in providers’ advice (aOR = 4.95, 95%CI:1.99, 12.43), perceived effectiveness of the vaccine (aOR: 12.18, 95%CI: 5.21–28.50), and experienced influenza-like illnesses in the family in the past year (aOR = 46.52, 4.10, 533.78) were associated with higher vaccine uptake.ConclusionsOlder people had suboptimal vaccine uptake compared to children in both contexts and need more attention to enhance influenza vaccination. Tailoring interventions to different vaccine funding contexts may help improve influenza vaccination: In self-paid context, motivating people to accept their first ever influenza vaccination may be a promising strategy. In subsidized context, improving public confidence in vaccine effectiveness and providers’ advice would be useful.

History of influenza immunization in COVID-19 patients: impact on mortality.

In the context of the COVID-19 pandemic, there is concern regarding the impact of the influenza season. To analyze the impact of influenza immunization history on patients with SARS-CoV-2 infection. Patients older than 18 years with COVID-19, registered between March and August 2020, were included. Data were analyzed using Fisher's exact test and Student's t-test. To evaluate the impact on mortality, a logistic regression model was used; the relationship between the percentage of patients who received the influenza vaccine and mortality was determined with Pearson's correlation coefficient. 16,879 participants were included; 17 % had a history of influenza vaccination. Mortality was lower in the group with a history of vaccination (3.5 % vs. 7 %, p < 0.0001). The vaccination rate had an inverse relationship with the mortality rate (Pearson's r: -0.922, p = 0.026). Previous influenza immunization was an independent protective factor for mortality in patients with COVID-19. Although further studies are needed to determine a causal relationship, it would be reasonable to increase influenza immunization in the general population.

The coverage of SARS-CoV-2 vaccination and the willingness to receive the SARS-CoV-2 variant vaccine among employees in China

BackgroundCOVID-19, which is caused by SARS-CoV-2, is a major global health threat. The dominant variant of SARS-CoV-2 has changed over time due to continuous evolution. We aimed to evaluate the coverage of SARS-CoV-2 vaccination among employees in China, explore their willingness to receive the SARS-CoV-2 variant vaccine and examine the potential factors influencing vaccination coverage and willingness.MethodsA cross-sectional epidemiological survey was conducted online from January 1, 2022, to January 30, 2022. The information collected in the survey included sociodemographic characteristics, lifestyle habits, vaccination coverage, willingness to be vaccinated against SARS-CoV-2 variants and the reasons for vaccination and willingness. Multivariable logistic regression models were used to assess the associations of potential factors with the rate of vaccination and the willingness to be vaccinated.ResultsAmong 62,395 eligible participants, the coverage of SARS-CoV-2 vaccination was 98.9% for at least one dose and 70.1% for a booster. The great majority of vaccinated individuals (94.4%) voluntarily received the vaccine. A total of 60,694 respondents (97.7%) were willing to be vaccinated against SARS-CoV-2 variants, mainly due to confidence in the effectiveness of vaccines (92.8%). A total of 1431 respondents were unwilling to be vaccinated, mainly because of concerns about the adverse effects of vaccines (77.6%). Longer education duration was associated with a higher rate of SARS-CoV-2 vaccination and willingness to be vaccinated. General or poor health status and having no history of influenza vaccination were associated with a lower rate of SARS-CoV-2 vaccination and willingness to be vaccinated. Additionally, we observed a significant positive association of abuse experience with the willingness to be vaccinated.ConclusionAlthough the rate of SARS-CoV-2 vaccination and the willingness to be vaccinated were relatively high in the study population, there were still some respondents with vaccine hesitancy. Relevant strategies based on significant related factors should be developed and implemented to encourage vaccination.