PPSV-23 recommendation and vaccination coverage in China: a cross-sectional survey among healthcare workers, older adults and chronic disease patients

The coverage and challenges of increasing uptake of non-National Immunization Program vaccines in China: a scoping review

BACKGROUND

Non-National Immunization Program (NIP) vaccines have played an important role in controlling vaccine-preventable diseases (VPDs) in China. However, these vaccines are paid out of pocket and there is room to increase their coverage. We focused on four selected non-NIP vaccines in this study, namely Haemophilus influenzae type b (Hib) vaccine, human papillomavirus (HPV) vaccine, pneumococcal conjugate vaccine (PCV), and rotavirus vaccine. We aimed to conduct a scoping review of their vaccination rates and the major barriers faced by health systems, providers, and caregivers to increase coverage.

METHODS

We followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Extension for Scoping Reviews (PRISMA-ScR). We searched five English databases (PubMed, Web of Science, EMBASE, Scopus, and WHO IRIS) and four Chinese databases using the search strategy developed by the study team. Two independent reviewers screened, selected studies, and examined their quality. We summarized the non-NIP vaccine coverage data by vaccine and applied the 5A framework (Access, Affordability, Acceptance, Awareness, Activation) to chart and analyze barriers to increasing coverage.

RESULTS

A total of 28 articles were included in the analysis (nine pertaining to vaccine coverage, and another 19 reporting challenges of increasing uptake). Among the four selected vaccines, coverage for the Hib vaccine was the highest (54.9-55.9% for 1 dose or more from two meta-analyses) in 2016, while the coverage of the other three vaccines was lower than 30%. Eight of the nine included articles mentioned the regional disparity of coverage, which was lower in under-developing regions. For example, the three-dose Hib vaccination rate in eastern provinces was 38.1%, whereas the rate in central and western provinces was 34.3% and 26.2%, respectively in 2017. Within the 5A framework, acceptance, awareness, and affordability stood out as the most prominent themes. Among the 12 identified sub-themes, high prices, low vaccine awareness, concerns about vaccine safety and efficacy were the most cited barriers to increasing the uptake.

CONCLUSIONS

There is an urgent need to increase coverage of non-NIP vaccines and reduce disparities in access to these vaccines across regions. Concerted efforts from the government, the public, and society are required to tackle the barriers and challenges identified in this study, both on the demand and supply side, to ensure everybody has equal access to life-saving vaccines in China. Particularly, the government should take a prudent approach to gradually incorporate non-NIP vaccines into the NIP step by step, and make a prioritizing strategy based on key factors such as disease burden, financial resources, and market readiness, with special attention to high-risk populations and underdeveloped regions.

Baseline Pneumococcal IgG Levels and Response to 23-Valent Pneumococcal Polysaccharide Vaccine among Adults from Beijing, China

PURPOSE

To investigate the baseline levels of serotype-specific IgG antibodies to Streptococcus pneumoniae (S. pneumoniae) and assess their impact on the assessment of vaccine immunogenicity.

METHODS

We used a subset of serum samples from a randomized controlled trial. The blood of 584 healthy participants was collected on day 0 before and day 28 after the 23-valent pneumococcal polysaccharide vaccine (PPSV23) vaccination. Serotype-specific IgG against PPSV23-covered serotypes were measured by the World Health Organization (WHO) reference enzyme-linked immunosorbent assay (ELISA). Vaccine immunogenicity was compared using conversion rates (proportion of participants with IgG levels following immunization that are 2-fold greater than the baseline) and geometric mean fold rises (GMFRs) between the two groups, which were grouped according to pre-vaccination (baseline) IgG antibody levels.

RESULTS

Our data showed that over half of individuals have baseline IgG levels for 15 out of 23 serotypes above 1.3 µg/mL, and geometric mean concentrations (GMCs) were generally higher in the elderly group and the female group; significant differences were found in 15 serotypes for vaccine immunogenicity based on the seroconversion rate or GMFRs between individuals with baseline IgG ≥ 1.3 µg/mL and individuals with baseline IgG < 1.3 µg/mL. The seroconversion rate decreased with the increase of baseline IgG levels according to a linear regression model.

CONCLUSIONS

The assessment of vaccine immunogenicity could be impacted by the fact that many adults had high baseline antibody levels. This study is registered in the Chinese Clinical Trial Registry, number NCT05298800.

Factors associated with recommendation behaviors of four non-National Immunization Program vaccines: a cross-sectional survey among public health workers in China

BACKGROUND

Immunization is a crucial preventive measure to safeguard children under five years old against a range of diseases. In China, the coverage rate of non-National Immunization Program (non-NIP) vaccines can be improved by leveraging the recommendation from public health workers. Hence, understanding the influencing factors of recommendation behaviors assume paramount importance. This study aims to investigate influencing factors of public health workers' recommendation behaviors towards non-NIP vaccines, with a particular emphasis on financial incentives.

METHODS

A cross-sectional survey was conducted using a multi-stage sampling method in 2019 from August to October. 627 public health workers were recruited from 148 community healthcare centers in ten provincial-level administrative divisions in China. An anonymous questionnaire was used to collect demographic information, attitudes towards vaccination, and recommendation behaviors towards non-NIP vaccines, including Haemophilus influenzae type b (Hib) vaccine, pneumococcal conjugate vaccine, varicella vaccine, and rotavirus vaccine. Descriptive analysis and multivariate logistic regression analysis were adopted in this study.

RESULTS

Of the 610 public health workers with complete survey data, 53.8%, 57.4%, 84.1%, and 54.1% often recommended Hib vaccine, pneumococcal pneumonia vaccine (PCV), varicella vaccine, and rotavirus vaccine, respectively. Logistic regression revealed that gender (Hib vaccine: OR = 0.4, 95% CI: 0.2-0.8; PCV: OR = 0.4, 95% CI: 0.2-0.8; rotavirus vaccine: OR = 0.3, 95% CI: 0.2-0.6), financial incentives for non-NIP vaccination (Hib vaccine: OR = 1.9, 95% CI: 1.1-3.6; PCV: OR = 2.1, 95% CI: 1.1-3.9; rotavirus vaccine: OR = 2.0, 95% CI: 1.1-3.8) and perception of vaccine safety (Hib vaccine: OR = 2.7, 95% CI: 1.1-7.0; PCV: OR = 3.2, 95% CI: 1.2-8.0; rotavirus vaccine: OR = 3.0, 95% CI: 1.2-7.7) were associated with public health workers' recommendation towards Hib vaccine, PCV and rotavirus vaccine.

CONCLUSIONS

The findings highlighted public health workers' recommendation behaviors of non-NIP vaccines in China and revealed strong association between vaccine recommendation and financial incentives. This highlights the importance of financial incentives in public health workers' recommendation toward non-NIP vaccines in China. Proper incentives are recommended for public health workers to encourage effective health promotion in immunization practices.

Assessing the impact of the 2018 Changchun Changsheng vaccine incident on childhood vaccination in China

BACKGROUND

The 2018 Changchun Changsheng vaccine incident is an emergent public health event in China with reports of DTaP vaccines with compromised efficacy. This study aimed to estimate the impact of the vaccine incident on real-world vaccination behaviors in China.

METHODS

A cross-sectional survey was conducted in ten provinces in 2019. Vaccination records were collected from 5294 children aged 6-59 months, with information on 75,579 vaccine doses for seven National Immunization Program (NIP) vaccines and two non-NIP vaccines received from 2014 to 2019. Chi-square test, interrupted time series, and logistic regression were used to evaluate the impacts of vaccine incident on vaccination delay, measured as the proportion of delayed doses out of total doses in schedule.

RESULTS

Here we show significant increases in doses delayed ≤ 3 months (19.12% to 22.51%, p = 0.000) and > 3 months (7.17% to 11.82%, p = 0.000) for DTaP vaccine after the incident. By scaling nationally, there will be extra 2.1 million doses delayed ≤ 3 months and 2.8 million doses delayed > 3 months in the year following this incident. More guardians choose expensive private-market substitutes containing DTaP elements over government-funded DTaP vaccines. Controlling for socio-demographic factors, doses scheduled after the incident have higher odds of delays for DTaP vaccine (OR: 3.49, 95% CI: 3.08-3.96) and other NIP vaccines (OR: 2.76, 95% CI: 2.55-2.99), but not for non-NIP vaccines.

CONCLUSIONS

The observed delays in the incident-involved DTaP vaccine immunization reflect the negative effects of the vaccine incident on vaccination behaviors under the NIP. However, its effects seem minimal for non-NIP vaccines.