Influenza vaccination uptake and its determinants during the 2019-2020 and early 2020-2021 flu seasons among migrants in Shanghai, China: a cross-sectional survey

Changes of influenza vaccination rate and associated influencing factors after the COVID-19 pandemic in Shanghai, China

The vaccination rate for seasonal influenza remains low in most regions of China. It is essential to understand the factors that associated with the low influenza vaccination rate in various populations after the COVID-19 pandemic. A cross-sectional survey was conducted with residents in Pudong New Area, Shanghai, China. Respondents' vaccination condition during the 2021-2022 flu season and the reasons for receiving or not receiving influenza vaccine were investigated. Binary logistic regression was conducted to explore potential factors influencing vaccination uptake. 2,476 of 14,001 respondents received an influenza vaccine, with a total coverage of 17.68% (95% CI: 17.05%, 18.32%). Children had the highest vaccination coverage (35.68%; 95% CI: 34.02, 37.33), followed by adults (12.75%; 95% CI: 11.91%, 13.58%) and elderly individuals (11.70%, 95% CI: 10.78%, 12.62%). For children, lower household income was an significant promoting factor. For adults, factors significantly associated with vaccination were household income, sex, and education level. For elderly, factors significantly associated with vaccination were household income, education level, living state, and having underlying diseases. (P < .05)The main reason for vaccine hesitancy among children was worried about side effects (21.49%), for adults and elderly was self-rated good health (adults: 37.14%, elderly people: 30.66%). The overall influenza vaccination coverage rate in Shanghai, especially among elderly individuals, is lower than many developed countries. Appropriate strategies and programs targeting different populations need to be implemented to enhance influenza vaccine coverage.

Impact of COVID-19 on vaccine confidence and uptake: A systematic literature review

During the coronavirus disease 2019 (COVID-19) pandemic, scheduled vaccinations were postponed, mass vaccination programmes were suspended and opportunities for healthcare workers to administer vaccines ad hoc decreased. The aims of this systematic literature review were to determine the impact of the COVID-19 pandemic on vaccine confidence, intent and uptake in preexisting routine childhood or adult vaccination programmes, and to identify factors associated with changes in acceptance, intent and uptake of preexisting vaccines. Medline and Embase were searched for studies in Australia, Brazil, Canada, China, Japan, the USA, and European countries, published between 1 January 2021 and 4 August 2022. A complementary gray literature search was conducted between 11 and 13 October 2022, and supplemented with additional gray research in October 2023. In total, 54 citations were included in the review. Study design and geography were heterogeneous. The number of adults who received or intended to receive an influenza or pneumococcal vaccine was higher during the pandemic than in previous seasons (n = 28 studies). In addition, increased acceptance of adult vaccinations was observed during 2020-21 compared with 2019-20 (n = 12 studies). The rates of childhood vaccinations decreased during the COVID-19 pandemic across several countries (n = 11 studies). Factors associated with changes in intention to receive a vaccination, or uptake of influenza vaccine, included previous vaccination, older age, higher perceived risk of contracting COVID-19, anxiety regarding the pandemic and fear of contracting COVID-19. Acceptance and uptake of influenza and pneumococcal vaccines generally increased after onset of the COVID-19 pandemic.

The impact of the COVID-19 pandemic and the free vaccination policy on seasonal influenza vaccination uptake among older adults in Ningbo, Eastern China

In 2020-21, during the COVID-19 pandemic, a free influenza vaccination program was initiated among the elderly residents in Ningbo, China. The impact of the COVID-19 pandemic and free vaccination policy on influenza vaccine uptake needs to be evaluated. The influenza vaccine uptake among individuals born before 31 December, 1962 from 2017-18 to 2022-23 season in Ningbo was analyzed. Multivariate logistic regressions were used to estimate the impact of the COVID-19 pandemic and free vaccination policy. Our analysis included an average of 1,856,565 individuals each year. Influenza vaccination coverage increased from 1.14% in 2017-18 to 33.41% in 2022-23. The vaccination coverage among the free policy target population was 50.03% in 2022-23. Multivariate analysis showed that free vaccination policy increased influenza vaccine uptake most (OR = 11.99, 95%CI: 11.87-12.11). The initial phase of the pandemic was associated with a positive effect on influenza vaccination (OR = 2.09, 95%CI: 2.07-2.12), but followed by a negative effect in the subsequent two seasons(2021-22: OR = 0.75, 95%CI: 0.73-0.76; 2022-23: OR = 0.40, 95%CI: 0.39-0.40). COVID-19 vaccination in the current season was a positive predictor of influenza vaccine uptake while not completing booster COVID-19 vaccination before was negative predictor in 2022-23. Having influenza vaccine history and having ILI medical history during the last season were also positive predictors of influenza vaccine uptake. Free vaccination policies have enhanced influenza vaccination coverage among elderly population. The COVID-19 pandemic plays different roles in different seasons. Our study highlights the need for how to implement free vaccination policies targeting vulnerable groups with low vaccination coverage.

Influenza vaccination before and during the COVID-19 pandemic in the elderly in South Korea

BACKGROUND

Influenza epidemics are a significant cause of mortality and morbidity in older adults; thus, vaccination is recommended. However, the coronavirus disease 2019 (COVID-19) pandemic could affect influenza vaccination.

METHODS

The influenza vaccination rate was estimated from the Korea Community Health Survey data from 2011 to 2021 using Joinpoint regression. We used multiple logistic regression analysis from each two flu seasons data before (2017-18 and 2018-19 seasons) and during (2019-20 and 2020-21 seasons) the COVID-19 pandemic to identify older adults who were not been vaccinated during the COVID-19 pandemic. Additionally, we stratified changes in influenza vaccination according to the flu season, demographic and socioeconomic characteristics, and health status.

RESULTS

The annual percentage change in influenza non-vaccination rate from 2010-11 to 2018-19 seasons and from 2019-20 to 2020-21 seasons was -8.31% (confidence interval (CI), -9.60 to -7.00) and 11.41% (CI, -3.22 to 28.25), respectively. Compared to before COVID-19, in the 2019-20 and 2020-21 seasons, the odds ratio (OR) of non-vaccination was 0.87 (CI, 0.83-0.91) and 1.18 (95% CI, 1.13-1.24), respectively. The decrease in influenza vaccination among older individuals with higher education (OR, 1.24; CI, 1.11-1.39) was greater than that among those with lower education (OR, 1.09; CI, 0.98-1.22). Older individuals with the lowest income level or poor self-rated health showed reduced influenza vaccination.

CONCLUSIONS

We estimated the trends of influenza vaccination and identified subgroups with decreased vaccination rates during the COVID-19 pandemic among older adults in South Korea. Health policy decision-makers, practitioners, and researchers should consider the implications of COVID-19 on changes in influenza vaccination, particularly for older individuals at risk of influenza.

Determinants of compliance to influenza and COVID-19 vaccination in a cohort of solid organ transplant patients in Puglia, Southern Italy (2017-2022)

Influenza and Coronavirus Disease 2019 (COVID-19) vaccination are recommended in both solid organ transplant (SOT) candidates and recipients. In Puglia, Southern Italy, an active vaccination offer program has been activated targeting these patients. This study aims at investigating vaccination coverage (VC) for both vaccines in a SOT patients' cohort, as well as at identifying the vaccination compliance determinant. This is a retrospective, population-based study. The study population consists of the SOT patients who accessed Bari's "Policlinico" General Hospital during 2017-2022. Patients were contacted and, after providing their consent, asked their immunization status regarding influenza and COVID-19 and whether they had already undergone transplant or were waiting to do so. Regression models were fitted to investigate the determinants of VCs for influenza vaccination (2021/22 and 2022/23 seasons) and for COVID-19 vaccination (three-dose base cycle, first and second booster doses). Three-hundred and ten SOT patients were identified; 85.2% (264/310) had already undergone SOT. VCs were suboptimal, especially for constant yearly influenza vaccination (17.7%) and COVID-19 vaccination's second booster (1.94%). Logistic regression highlighted that influenza VCs are higher for SOT recipients than SOT candidates, as well as for older patients, although when considering both vaccination seasons only age significantly impact the vaccination uptake. Older age was the only influential variable for COVID-19 VC. VCs for SOT patients seem to be unsatisfying. Stronger interventions are required.

Evaluation of influenza vaccination coverage in Shanghai city during the 2016/17 to 2020/21 influenza seasons

Influenza is a common infectious disease resulting in substantial morbidity and mortality globally. The most effective strategy for preventing influenza is annual vaccination; however, the coverage rate of the influenza vaccine in Shanghai has not been well explored or reported. Therefore, this study aimed to determine coverage with the influenza vaccine and access trends in Shanghai city; data from Shanghai immunization information system was analyzed to estimate vaccination coverage during 2016–2017 through 2020–2021 influenza seasons. Vaccination coverage by age groups, immigration status, and districts was accessed. The influenza vaccination coverage (at least one dose) for 2016/2017 to 2020/2021 influenza seasons was 10.8‰ (95‰ CI: 10.7–10.8), 12.3‰ (95‰ CI: 12.3–12.4), 10.1‰ (95‰ CI: 10.0–10.1), 20.1‰ (95‰ CI: 20.0–20.2) and 50.8‰ (95‰ CI: 50.7–50.8) respectively. Although we found significantly higher vaccination coverage in females, children from 6 months to 17 years, and residents, it is still low in all subgroups of the population in Shanghai. Therefore, taking effective steps to promote influenza vaccination in Shanghai is recommended.

Acceptance of the COVID-19 vaccine based on the health belief model: a multicenter national survey among medical care workers in China

Vaccine uptake rate is crucial for herd immunity. Medical care workers (MCWs) can serve as ambassadors of COVID-19 vaccine acceptance. This study aimed to assess MCWs’ willingness to receive the COVID-19 vaccine, and to explore the factors affecting COVID-19 vaccination acceptance. A multicenter study among medical care workers was conducted in seven selected hospitals from seven geographical territories of China, and data were collected on sociodemographic characteristics, vaccine hesitancy, and health beliefs on COVID-19 vaccination among participants. Univariate and multivariate logistic regression models were performed to explore the correlations between individual factors and the acceptance of the COVID-19 vaccine. Among the 2681 subjects, 82.5% of the participants were willing to accept the COVID-19 vaccination. Multivariate regression analyses revealed that individuals with more cues to action about the vaccination, higher level of confidence about the vaccine, and higher level of trust in the recommendations of COVID-19 vaccine from the government and the healthcare system were more likely to get the COVID-19 vaccine. In contrast, subjects with higher level of perceived barriers and complacency were less likely to accept the COVID-19 vaccine. Overall, MCWs in China showed a high willingness to get the COVID-19 vaccine. The governmental recommendation is an important driver and lead of vaccination. Relevant institutions could increase MCWs’ willingness to COVID-19 vaccines by increasing MCWs’ perception of confidence about COVID-19 vaccines and cues to action through various strategies and channels. Meanwhile, it can also provide evidence in similar circumstances in the future to develop vaccine promotion strategies.