On-time Measles and Pneumococcal Vaccination of Shanghai Children: The Impact of Individual-level and Neighborhood-level Factors

Timeliness of routine childhood vaccination in 103 low-and middle-income countries, 1978-2021: A scoping review to map measurement and methodological gaps

Empiric studies exploring the timeliness of routine vaccination in low-and middle-income countries (LMICs) have gained momentum in the last decade. Nevertheless, there is emerging evidence suggesting that these studies have key measurement and methodological gaps that limit their comparability and utility. Hence, there is a need to identify, and document these gaps which could inform the design, conduct, and reporting of future research on the timeliness of vaccination. We synthesised the literature to determine the methodological and measurement gaps in the assessment of vaccination timeliness in LMICs. We searched five electronic databases for peer-reviewed articles in English and French that evaluated vaccination timeliness in LMICs, and were published between 01 January 1978, and 01 July 2021. Two reviewers independently screened titles and abstracts and reviewed full texts of relevant articles, following the guidance framework for scoping reviews by the Joanna Briggs Institute. From the 4263 titles identified, we included 224 articles from 103 countries. China (40), India (27), and Kenya (23) had the highest number of publications respectively. Of the three domains of timeliness, the most studied domain was 'delayed vaccination' [99.5% (223/224)], followed by 'early vaccination' [21.9% (49/224)], and 'untimely interval vaccination' [9% (20/224)]. Definitions for early (seven different definitions), untimely interval (four different definitions), and delayed vaccination (19 different definitions) varied across the studies. Most studies [72.3% (166/224)] operationalised vaccination timeliness as a categorical variable, compared to only 9.8% (22/224) of studies that operationalised timeliness as continuous variables. A large proportion of studies [47.8% (107/224)] excluded the data of children with no written vaccination records irrespective of caregivers' recall of their vaccination status. Our findings show that studies on vaccination timeliness in LMICs has measurement and methodological gaps. We recommend the development and implement of guidelines for measuring and reporting vaccination timeliness to bridge these gaps.

Effectiveness of 13-valent pneumococcal conjugate vaccine against community acquired pneumonia among children in China, an observational cohort study

BACKGROUND

In China, 13-valent pneumococcal conjugate vaccine (PCV13) has been available since 2017, but only via the private market with low uptake rate. We assessed the direct effectiveness of PCV13 against community acquired pneumonia (CAP) associated with PCV13 serotype carriage (VT-CAP).

METHODS

We conducted an observational cohort study of children born during 12-Dec-2016 to 30-Nov-2018 identified in the Suzhou Centers for Disease Control vaccine registry database, and who had at least one inpatient or outpatient record at the Suzhou University Affiliated Children's hospital (SCH) health-information-system (HIS) database. The vaccine registry cohort was followed through the HIS database through 30-Jun-2019 to identify hospitalized VT-CAP. Pneumococci were isolated from deep upper respiratory aspirates and serotyped with Quellung reactions.

RESULTS

We included 139,127 children of whom 9024 (6.5%) received 1 + PCV13 doses (95.8% received 2 + doses). Within the total cohort, we identified 548 children hospitalized at SCH for VT-CAP, of whom 10 had received 2 + PCV13 doses. Adjusted for demographics, receipt of other childhood vaccines, and underlying medical conditions, the first visit vaccine effectiveness among children who had received 2 + PCV13 doses was 60.9% (95% CI: 25.8% to 79.4%) for VT-CAP and 17.9% (95% CI: 5.5% to 28.6%) for clinical CAP. Incidence rate reductions per 100,000 child-years of observation for all visits were 208 (95% CI: 118 to 298) for VT-CAP and 720 (95% CI: 304 to 1135) for clinical CAP.

CONCLUSIONS

PCV13 was protective against hospitalized VT-CAP and clinical CAP with large associated incidence rate reductions among children living in Suzhou, China.

Factors impacting self-pay pediatric vaccine utilization in China: a large-scale maternal survey

OBJECTIVES

Utilization of self-pay vaccines worldwide is very low, especially in China; the reasons for this are unclear. We aimed to identify factors that impact the decision among Chinese mothers to utilize self-pay vaccines for their children.

METHODS

Mothers who were hospitalized at two hospitals in Zhanjiang City and who agreed to participate by completing the required questionnaire were eligible for this study.

RESULTS

In total, 7518 respondents (n = 7592) completed the questionnaire and were included in this survey. The self-pay option was largely elected by mothers with one child, compared with those who had two or more children. Similarly, utilization by workers at government agencies and organizations was higher than that among factory workers or unemployed respondents. Mothers with a college degree or above had higher utilization than those with a high school level education or lower. The main issues affecting maternal decisions to utilize self-pay pediatric vaccines were safety, the protective effect, and the high cost.

CONCLUSION

Mothers with higher socioeconomic status were more inclined to self-pay for pediatric vaccines. Steps taken to enhance public awareness about the safety and protective benefits of self-pay vaccines, as well as lowering their cost will likely encourage broader utilization of these vaccines.

Vaccination timeliness and delay in low- and middle-income countries: a systematic review of the literature, 2007-2017

Background: Traditional measurements of vaccine coverage at specific ages can mask poor vaccine timeliness. However, optimal measurement of timing is unclear due to variations in countries’ recommended vaccination schedules and lack of a commonly accepted standard for “timeliness”. We conducted a systematic review of literature on vaccine timeliness and delay in low- and middle-income countries from 2007 to 2017.

Methods: A search of articles published between January 1 2007 and December 31 2017, was performed in PubMed, EBSCOhost, and Embase.

Results: 67 papers were included, of which 83% used a categorical measure of delay and 41% evaluated continuous delay. The most common age at assessment was 1 month, with earlier age benchmarks typically used with birth doses.

Conclusions: Categorical definitions of vaccination timing vary widely, with benchmarks of delay varying from days to weeks to months. Use of a continuous measure of vaccine delay may be more informative and comparable.

Neighbourhood influence on the fourth dose of diphtheria-tetanus-pertussis vaccination

OBJECTIVES

Using 542,159 vaccination records from children born between April 1, 2007, and March 31, 2012, in the Michigan Care Improvement Registry and data from the American Community Survey, we determine if neighbourhood-level characteristics at the Census tract level and block level are associated with low uptake of the fourth dose of diphtheria-tetanus-acellular pertussis vaccine (DTaP4).

STUDY DESIGN

This study was a cross-sectional study.

METHODS

We used exploratory factor analysis to determine important socio-economic factors at the Census block level and tract level. We then used generalised estimating equations to test the relationship between block- and tract-level socio-economic factors and DTaP4 uptake.

RESULTS

DTaP4 coverage was 88.6% (95% confidence interval [CI]: 88.4%-88.7%) in Michigan. At the Census tract level, two factors surfaced as important for DTaP4 vaccination: 'affluence' (Cronbach's alpha = 0.88) and 'socio-economic disadvantage' (Cronbach's alpha = 0.89). At the Census block level, one factor was important: 'affluence' (Cronbach's alpha = 0.90). Affluence may relate to knowledge about medical exemptions and antivaccination sentiment, while socio-economic disadvantage may indicate limited access to healthcare resources. Children in high-affluence tracts had 1.08% lower vaccination coverage (95% CI: -1.62% to -0.55%) than children in low affluence tracts. Children in low socio-economic disadvantage tracts had 2.92% higher coverage than children in high socio-economic disadvantage tracts (95% CI: 2.58%-3.26%).

CONCLUSIONS

This study articulates the need to further understand the contribution of neighbourhood-level characteristics, from both affluent and socioeconomically disadvantaged areas to low vaccination rates. Developing a better understanding of these social environmental factors will help determine useful community-level interventions to improve vaccination rates and reduce disease burden.

Parent and caregiver perceptions about the safety and effectiveness of foreign and domestic vaccines in Shanghai, China

Background

Chinese parents have access to domestic and foreign vaccines for their children. Their vaccine preferences are unclear, especially given recent pharmaceutical quality scandals and widely held beliefs deriving from Traditional Chinese Medicine (TCM). This study characterized parental beliefs about the safety and effectiveness of Chinese and foreign vaccines.

Methods

In May 2014, caregivers of young children at public immunization clinics in Shanghai, China, responded to a survey on vaccine perceptions. The two outcomes (differential belief in the effectiveness and safety of foreign vs domestic vaccines) were separately regressed onto demographic predictors in multinomial logistic regression models.

Results

Among 618 caregivers, 56% thought the effectiveness of domestic and foreign vaccines were comparable; 33% thought domestic were more effective and 11% foreign. Two-thirds thought foreign and domestic vaccines had similar safety; 11% thought domestic were safer and 21% thought foreign were safer. Compared to college graduates, those with a high school education or less had greater odds of believing domestic vaccines were more effective, and also had greater odds of believing imported vaccines were safer. Greater trust in TCM was not associated with differential beliefs in the effectiveness or safety of domestic vs foreign vaccines.

Conclusions

Although there is no evidence that foreign and domestic vaccines differ in either effectiveness or safety, less educated caregivers in China (but not those with greater trust in TCM) appear to believe such differences exist. Further exploration of the causes of these beliefs may be necessary in order to optimize vaccine communications in China.

Parents' concerns about vaccine scheduling in Shanghai, China

BACKGROUND

Several new vaccines have been introduced into China in recent years, but some parents in China have shown concerns about the scheduling of vaccinations for young infants. This study explores caregiver concerns about children receiving multiple vaccines during a single visit and about vaccine administration in infants <6months, and assesses the degree to which these concerns are associated with ratings of the importance of different sources of vaccine information in Shanghai.

METHODS

Caregivers of children 8months to 7years presenting at immunization clinics in Shanghai completed a survey about vaccine co-administration and vaccine administration <6months of age. Respondents provided ratings of information from different sources (Internet, family/friends, other parents) and trust in doctors. We analyzed vaccine concerns using linear regression analyses that included these information sources after adjusting for socioeconomic variables.

RESULTS

Among 618 caregivers, 64% were concerned about vaccine co-administration and 31% were concerned about vaccine administration to infants <6months of age. Higher ratings of Internet as an important source of information were associated with greater concern about co-administration (β=0.11, 95% CI: 0.00, 0.22) and concern about administration at <6months of age (β=0.17, 95% CI: 0.05, 0.28). Higher ratings given to information from other parents corresponded to 0.24 points greater concern about vaccine co-administration (95% CI: 0.04, 0.44). More trust in doctors and ratings of information from friends and family were not associated with vaccine concerns.

CONCLUSIONS

Caregiver concerns about vaccine scheduling may limit China's flexibility to add vaccines to its official immunization schedule. Reporting information about vaccine safety on the Internet and bringing groups of parents together to discuss vaccines might help to ameliorate concerns about vaccine scheduling.

Perceptions of measles, pneumonia, and meningitis vaccines among caregivers in Shanghai, China, and the health belief model: a cross-sectional study

BACKGROUND

In China, the measles vaccine is offered for free whereas the pneumococcal vaccine is a for-fee vaccine. This difference has the potential to influence how caregivers evaluate whether a vaccine is important or necessary for their child, but it is unclear if models of health behavior, such as the Health Belief Model, reveal the same associations for different diseases. This study compares caregiver perceptions of different diseases (measles, pneumonia and meningitis); and characterizes associations between Health Belief Model constructs and both pneumococcal vaccine uptake and perceived vaccine necessity for pneumonia, measles, and meningitis.

METHODS

Caregivers of infants and young children between 8 months and 7 years of age from Shanghai (n = 619) completed a written survey on their perceptions of measles, pneumonia, and meningitis. We used logistic regression models to assess predictors of pneumococcal vaccine uptake and vaccine necessity.

RESULTS

Only 25.2% of children had received a pneumococcal vaccine, although most caregivers believed that pneumonia (80.8%) and meningitis (92.4%), as well as measles (93.2%), vaccines were serious enough to warrant a vaccine. Perceived safety was strongly associated with both pneumococcal vaccine uptake and perceived vaccine necessity, and non-locals had 1.70 times higher odds of pneumonia vaccine necessity than non-locals (95% CI: 1.01, 2.88).

CONCLUSIONS

Most factors had a similar relationship with vaccine necessity, regardless of disease, indicating a common mechanism for how Chinese caregivers decided which vaccines are necessary. Because more caregivers believed meningitis needed a vaccine than pneumonia, health care workers should emphasize pneumococcal vaccination's ability to protect against meningitis.