Vaccine最新文献

Introduction: This study examined associations between information sources and COVID-19 vaccination behavior among pregnant and postpartum women in Brazil, Ghana, Kenya, and Pakistan.

Methods: This mixed methods study involved concurrent in-depth interviews and cross-sectional surveys.

Results: A total of 1797 women participated in the study. Overall, participants were more likely to be vaccinated if they believed that they knew enough about safety to make a decision (aOR: 1.51; CI: 1.04-2.20) and trusted the information they received from healthcare providers (aoR: 1.74; CI: 1.19-2.54). Odds of vaccination were higher among those who trusted information provided by scientists (aoR:1.86; CI: 1.31-2.63) and among those who believed that leaders in their community recommended the COVID-19 vaccine (aOR: 1.4; CI: 1.01-1.92). Higher odds of vaccination were observed among participants in Pakistan who had the information they needed to make a decision (aOR: 2.58; CI: 1.35-4.94), knew enough about safety to make a decision (aOR: 3.82; CI: 1.85-7.89), trusted the information they received from healthcare providers (aOR: 3.20; CI: 1.39-7.34), and believed that community leaders recommended the COVID-19 vaccine (aOR: 2.53; CI: 1.22-5.25). Participants in Brazil who trusted information provided by scientists (aOR: 4.70; CI: 1.23-18.05); participants in Kenya who trusted information from the media (aOR: 1.94; CI: 1.10-3.44); and participants in Ghana who trusted recommendations from their government (aOR: 2.66; CI: 1.42-5.0) had higher odds of vaccination. Interviewed women noted that they felt overwhelmed with the amount of information and misinformation related to COVID-19 and the vaccine specifically.

Discussion: Trusted COVID-19 vaccine information sources reported by pregnant and postpartum women vary by country, suggesting the need to identify sources across different target populations to improve vaccine acceptability and uptake with the goal of realizing the population level benefits of vaccination.

Background: Among pregnant and postpartum women, decision-making for receiving the COVID-19 vaccine is influenced by vaccine safety concerns, misconceptions, shifting vaccine policies, and exclusion in the initial vaccine rollout. This caused confusion and vaccine hesitancy among many groups including pregnant and postpartum women.

Objective: The objective of this study was to understand the multilevel factors that influence vaccine decision-making among pregnant and postpartum women in Pakistan, which is crucial for improving vaccine demand among the vulnerable group-pregnant and postpartum women.

Methods: This study is part of a multi-country mixed method study conducted in Brazil, Ghana, Kenya, and Pakistan. In Pakistan, fifty in-depth interviews were conducted with pregnant and postpartum women from two hospitals in Karachi. A grounded theory analysis approach was used, and a socio-ecological framework encompassing four levels of influence was applied to synthesize the study findings.

Results: At the individual level, influences included concerns about vaccine safety, particularly regarding the health of the women and their babies due to potential side effects. Strong religious beliefs and trust in God also deterred some women from receiving the COVID-19 vaccine, as they relied on their faith practices. However, women with confidence in the vaccine had a positive attitude toward vaccination. At the interpersonal level, factors influencing vaccine decisions included the strong influence of observing others and recommendations from family and healthcare providers. Community-level factors included misconceptions about the vaccine's purpose and effects, and religious leaders' recommendations either supporting or discouraging vaccination. Policy-level factors involved mandatory vaccination for accessing public spaces, employment, and healthcare services. Coercive vaccination policies led some women to obtain vaccine cards without getting vaccinated.

Conclusions: Efforts to promote vaccination among pregnant and postpartum women in Pakistan should engage family members, healthcare providers, and religious leaders, and implement evidence-based vaccine mandates to increase demand and to support uptake of maternal COVID-19 vaccination.

Background: This prospective study aimed to evaluate the dynamics and seroprevalence of anti-SARS-CoV-2 antibodies in a cohort of vaccinated and unvaccinated health workers (HWs) in Bamako, Mali. The study also measured antibody responses as a function of SARS-CoV-2 infections, socio-demography, vaccination status and associated comorbidities.

Method: 685 vaccinated and 413 unvaccinated HWs (total = 1098) were monitored over a 15-month periods with follow-up visits every 3 months for the first 6 months and a final visit after 15 months. Anti-spike and anti-nucleoprotein antibodies were assessed using ELISA. Non-parametric tests and logistic regression analyses were performed to compare antibody levels and to investigate associated factors.

Results: Overall, anti-SARS-CoV-2 antibodies tended to increase over the first 3 months in both vaccinated and unvaccinated groups. Spike (>98 %) and nucleoprotein (>91 %) antibodies remained high and relatively stable after 3 months and correlated inversely with the rate attack of symptomatic and asymptomatic COVID-19. Males demonstrated lower antibody responses, particularly for nucleoprotein (p < 0.05) compared to females. HWs with comorbidities demonstrated higher antibody responses. Participants with active SARS-CoV-2 infections exhibited decreased antibody levels. Vaccinated participants exhibited a trend toward higher spike antibodies. Virus-inactivated type vaccination increased nucleoprotein antibodies. Furthermore, there was no increase of antibody levels after receiving, two or more vaccine doses, independently of whether the same or a different type of used vaccines. Nucleoprotein antibodies varied significantly at inclusion among participants across blood groups.

Conclusion: This study identified a progressive increase in anti-spike and anti-nucleoprotein antibodies in both vaccinated and unvaccinated HWs, correlating with reduced COVID-19 infection rates. These findings highlight the significance of both natural and vaccine-induced immunity and the need to assess antibody levels and long-term protection beyond the 15-month study period.

Background: Chengdu, China, is facing an increasing burden of cervical cancer. Although human papillomavirus (HPV) vaccines have been introduced in China since 2016, vaccination coverage remains suboptimal, and data on regional disparities are limited. In 2021, Chengdu implemented a subsidized HPV vaccination program targeting girls aged 13-14 years. This study aims to evaluate HPV vaccination coverage among females aged 9-45 years in Chengdu from 2017 to 2023, stratified by age group, geographic area, and vaccine type, and to examine changes in vaccination coverage among girls aged 13-14 years following the city's enrollment in the pilot subsidy program.

Methods: HPV vaccination data were sourced from the Sichuan Provincial Immunization Information System. Descriptive analyses assessed annual and cumulative vaccination coverage from 2017 to 2023 among females aged 9-45 years in Chengdu. An interrupted time series (ITS) analysis using a segmented regression model (SRM) was conducted to quantify changes in vaccination rates following program implementation among girls aged 13-14 years.

Results: From 2017 to 2023, first- and full-dose HPV vaccination coverage among females aged 9-45 years in Chengdu showed significant upward trends across age groups, geographic areas, and vaccine types. By 2023, cumulative first-dose coverage reached 34.17 %, with full-dose coverage at 24.40 %. Notably, vaccination rates for girls aged 13-14 years exhibited markedly higher first- and full-dose coverage compared to pre-program levels (β = 1.899, p-value = 0.002; β = 4.859, p-value <0.001, respectively).

Conclusions: Following the HPV vaccination program in Chengdu, the vaccination rate for girls aged 13-14 years significantly increased. However, the overall vaccination rate for women aged 9-45 years remains relatively low, particularly among certain subpopulations. To enhance overall vaccination rates, strategic priorities should include targeted interventions for subpopulations with suboptimal coverage, expansion of pilot programs, and stronger political commitment to integrating the HPV vaccine into the National Immunization Program.

Background: National Immunization Technical Advisory Groups (NITAGs) are crucial for enhancing vaccine use in immunization programs, particularly through off-label recommendations. This study sought to assess the adoption and trends of off-label vaccine recommendations made by NITAGs across low-, middle-, and high-income countries since the COVID-19 pandemic.

Methods: An online survey was distributed to NITAG representatives in World Health Organization (WHO) member states, asking questions related to off-label use of vaccines including policies, procedures, legislation, and regulations for NITAGs in participants' countries. Respondents across all six WHO regions were invited to participate.

Results: Respondents from 76 countries participated in the survey (55 %) were NITAG representatives, and 45 % were immunization program managers or from the NITAG secretariat). Most respondents 52 (68 %) reported their NITAG makes off-label recommendations, 18 (24 %) indicated their NITAG does not make off-label recommendations, and 6 (8 %) were unsure of their NITAG's role. There was a noticeable shift relating to off-label vaccine recommendations observed pre, during, and post-pandemic period. Prior to 2022, 25 (48 %) respondents indicated their country recommended off-label vaccines, 11 (21 %) specified off-label recommendations were limited to emergencies as temporary or conditional expansions, and 6 (12 %) were unsure. After 2022, 30 (58 %) respondents indicated their country recommended off-label vaccines, 4 (8 %) specified off-label recommendations were limited to emergencies as temporary or conditional expansions, 18 (35 %) selected no, and 0 (0%) were unsure. While most countries make off-label recommendations, few (15 %) have policies and procedures to support implementation.

Conclusions: Although WHO broadly provides guidance on the mandate and core functions of NITAGs, globally, they have differing mandates and operational capacities related to off-label vaccine use. These findings suggest the need for increased awareness of off-label vaccine recommendations and strengthened dialogue around implementation of off-label recommendations.

A primary series of two mRNA-1273 COVID-19 vaccinations did not induce robust antibody and T cell responses in a large proportion of kidney (KTR) and lung (LTR) transplant recipients. Interestingly, some of these transplant recipients showed spike-specific T cell responses without detectable antibodies. In order to improve the immunogenicity of vaccines in this vulnerable population, this finding warrants in-depth investigation of the spike-specific CD4⁺ T cell phenotype and functionality in these patients. In this in-depth study, we isolated peripheral blood mononuclear cells (PBMCs) from 17 KTR, 13 LTR, and 20 controls, who were previously classified as T cell responders based on IFN-γ ELISpot. The phenotype of the spike-specific CD4⁺ T cells was investigated using AIM assays, and the spike-specific cytokine secretion was measured in cell-culture supernatant following spike-specific stimulation. Twenty-eight days post-second vaccination, a lower frequency of spike-specific CD4⁺ T cells was observed in both KTRs and LTRs compared to controls. In all groups, these spike-specific CD4⁺ T cells were predominantly of the central and effector memory phenotype. Unsupervised hierarchical clustering revealed three distinct clusters of cytokine secretion profiles in the culture supernatants. The cluster with the lowest cytokine diversity had a higher frequency of terminally differentiated spike-specific CD4⁺ T cells. This cluster contained transplant recipients who were classified as antibody non-responders, were significantly shorter after transplantation, and more often received triple immunosuppressive therapy. The KTR with a restricted cytokine secretion profile also remained mostly antibody non-responders after a third vaccination. In conclusion, we show an association between the phenotype and functionality of spike-specific CD4⁺ T cells and the time after transplantation in transplant recipients. This knowledge aids the identification of transplant patients in need of alternative vaccination strategies and possible targets to improve efficacy of vaccines in these patients.

Background and objectives: Short and valid instruments measuring vaccination attitudes across countries are limited. The recently developed 12-item Vaccination Attitudes Examination (VAX) scale measures vaccination hesitancy and consists of four subscales: (1) mistrust of vaccine benefits, (2) worries over unforeseen future effects, (3) concerns about commercial profiteering, and (4) preference for natural immunity. The original English version has been translated and validated in different languages. This study aimed to validate the Danish translation of the VAX scale.

Methods: The Danish translation of the VAX scale was distributed to Danish citizens using social media via the online survey system SurveyXact. Confirmatory factor analysis (CFA) examined the factor structure. Internal consistency reliability was evaluated for the entire scale and all subscales. Known group validity was tested using vaccination status. Criterion validity was assessed using the beliefs about medicines questionnaire (BMQ).

Results: Analysis of responses from 194 participants revealed an adequate four-subscale construct (GFI = 0.939, AGFI = 0.901, NFI = 0.955, TLI = 0.976, CFI = 0.982, RMSEA = 0.056, SRMR = 0.037, p = 0.005) and a high internal consistency reliability (Cronbach's α 0.934 for the entire scale, 0.920, 0.824, 0.833, and 0.899 for the four subscales, respectively). COVID-19 vaccinated participants showed significantly lower VAX scale scores (Mean(SD) = 2.36(0.83)) compared to non-vaccinated (Mean(SD) = 4.88(0.93)). A significant correlation was found with BMQ-general (r = -0.716, p < 0.01).

Conclusion: The Danish translation of the VAX scale demonstrated a well-defined four-factor structure with high internal consistency, known group validity, and criterion validity. It is a useful tool to measure vaccination hesitancy in Denmark.

Background: Paediatric COVID-19 vaccination programmes were initiated in response to the coronavirus pandemic declared by the World Health Organisation (WHO) in 2020. Ten COVID-19 vaccines received WHO Emergency Use Listing, however, only five were approved for use in children. ChAdOx1 nCoV-19 (AZD1222) was approved in adults in a two-dose regimen. We previously reported interim findings of a phase 2 study of ChAdOx1 nCoV-19 in children with immunogenicity, comparable with adults. Final results after 12 month follow-up are reported.

Methods: Single-blind, randomised controlled trial across four UK centres, recruiting 261 children and adolescents (aged 6-17 years). Participants received either two doses of ChAdOx1 nCoV-19 or Bexsero vaccine (controls). The primary outcome was safety (adverse events for 28 days following vaccination and serious adverse events throughout), and secondary outcome was immunogenicity (measured by SARS-CoV-2 anti-spike enzyme-linked immunosorbent assay (ELISA) and enzyme-linked immunosorbent spot (ELISpot)).

Findings: Five serious adverse events and four adverse events of special interest were reported. None were related to study vaccinations, and there were no deaths. Geometric mean titres (GMTs) from an anti-spike (Wuhan) ELISA in participants aged 6-11 years were 1 EU/ml (95% CI 1-2) at baseline versus 796 EU (95% CI 161-3948, n =4) at D364. In participants aged 12-17 years, GMTs were 1 EU/ml (95% CI 1-2, n=3) at baseline versus 1432 EU/ml (95% CI 2337-6083; n=6) at D364 (2 dose regimen at 112-day interval), compared to 3 EU/ml (95% CI 0-62) at baseline versus 392 EU/ml (95% CI 24, 6493; n=3) at D364 (2 dose regimen at a 28-day interval).

Interpretation: A two-dose regimen of ChAdOx1 nCoV-19 was immunogenic and safe in the trial population. No vaccine-related serious adverse events were reported. Immune responses persisted to 12 months in participants who did not experience breakthrough infection, This trial was registered with ISRCTN, trial number 15638344.

Funding: The study was funded by the Department of Health and Social Care, through the National Institute for Health Research, and AstraZeneca.