Estimated public health impact of nationwide vaccination of infants with 7-valent pneumococcal conjugate vaccine (PCV7) in China

The Cost-Effectiveness of 13-Valent Pneumococcal Conjugate Vaccine in Seven Chinese Cities

Objective: This study estimates the cost-effectiveness of vaccination with the 13-valent pneumococcal conjugate vaccine (PCV13) among infants in Beijing, Shanghai, Shenzhen, Chengdu, Karamay, Qingdao, and Suzhou. Methods: A previously published cost-effectiveness model comparing vaccination with PCV13 to no vaccination was localized to the included Chinese cities. A systematic literature review was undertaken to identify age-specific incidence rates for pneumococcal bacteremia, pneumococcal meningitis, pneumonia, and otitis media (AOM). Age-specific direct medical costs of treating the included pneumococcal diseases were taken from the Chinese Health Insurance Association database. The base case analysis evaluated vaccine efficacy using direct effect and indirect effects (DE+ IDE). A subsequent scenario analysis evaluated the model outcomes if only DE was considered. A vaccination rate of 70% was used. The model reported outcomes over a one-year period after it was assumed the vaccine effects had reached a steady state (5–7 years after vaccine introduction) to include the direct and indirect effects of vaccination. Health outcomes were discounted at 5% during the steady-state period. Results: Vaccination with PCV13 was cost-effective in the base case analysis for all included cities with the incremental cost-effectiveness ratio (ICER) ranging from 1145 CNY(Shenzhen) to 15,422 CNY (Qingdao) per quality-adjusted life-year (QALY) gained. PCV13 was the dominant strategy in Shanghai with lower incremental costs and higher incremental QALYs. PCV13 remained cost-effective in the DE-only analysis with all ICERs falling below a cost-effectiveness threshold of three times GDP per capita in each city. Conclusions: Vaccination with PCV13 was a cost-effective strategy in the analyzed cities for both the DE-only and DE + IDE analyses. PCV13 became very cost-effective when a vaccination rate was reached where IDE is observed.

Dual influenza and pneumococcal vaccination was associated with lower short-term risks of all-cause and acute respiratory hospitalizations among the elderly in Shenzhen, China: a retrospective cohort study

The present study evaluated the real-world effectiveness of influenza and pneumococcal dual-vaccination among Chinese elderly, the evidence on which was absent. Outpatient and inpatient claims databases from Jan 1, 2015 to Apr 1, 2017 of persons at least 60 years old in Shenzhen, China were merged with electronic records of influenza vaccines and 23-valent pneumococcal polysaccharide vaccines (PPSV23) from Oct 1, 2016 - May 31, 2017. Individuals who were vaccinated with influenza between Nov 1 and Dec 31, 2016 and received PPSV23 30 days within the date of influenza vaccination were defined as the vaccinated group. A control group consisted of individuals that received neither of the vaccines was constructed by matching on year of birth, sex, and district. The two outcomes were all-cause and acute respiratory hospitalizations. Difference-in-difference (DiD) logistic regressions that were proceeded with an entropy balancing (EB) process were used to analyse the effectiveness of dual-vaccination. A total of 48,116 eligible individuals were identified in the vaccinated group, which were matched by 93,692 individuals in the control group. The EB-DiD analyses estimated that dual-vaccination was associated with lower short-term risks of all-cause (odds ratio: 0.59, CI: 0.55-0.63) and acute respiratory (odds ratio: 0.49, CI: 0.41-0.59) hospitalizations.

A systematic literature review of economic evaluations of pneumococcal conjugate vaccines in east and southeast Asia (2006-2019)

INTRODUCTION

Pneumococcal infections can lead to serious invasive diseases such as meningitis, septicemia and pneumonia, as well as milder but more common illnesses such as sinusitis and otitis media. The World Health Organization (WHO) recommends the inclusion of pneumococcal conjugate vaccines (PCVs) in infant National Immunization Program (NIP) programs worldwide. Decision-makers in Asian countries planning to introduce PCVs in their respective NIP will need a comprehensive evidence of effectiveness of PCVs at the population level and economic evidence including cost-effectiveness.

AREAS COVERED

A systematic literature review (from 1/1/2016 to 10/11/2019) of PCVs in East and Southeast Asia to understand (1) the contributing factors to cost-effectiveness results of PCVs and (2) whether gaps in evidence exist suggesting why the region may have yet to implement full NIPs.

EXPERT OPINION

In East and Southeast Asia, vaccination with PCVs was found to significantly reduce the mortality and morbidity of pneumococcal diseases and was cost-effective compared to no vaccination. Study assumptions, specifically vaccine local acquisition, the inclusion or exclusion of indirect effects (serotype replacement and herd effect), cross-protection, and protection against nontypeable haemophilus influenzae and serotype 3, were the main drivers of cost-effectiveness.

Serotypic distribution and antimicrobial resistance of Streptococcus pneumoniae in Chinese children under 5 years after the introduction of the 13-valent conjugate pneumococcal vaccine: protocol for a scoping review

The World Health Organization (WHO) recommends that pneumococcal conjugate vaccines (PCVs) be included in immunization programs worldwide. In China, the 7-valent pneumococcal conjugate vaccine (PREVNAR 7®) was authorized in 2008 but was not included in the national immunization programs. In 2016, PREVNAR 13®, a 13-valent pneumococcal conjugate vaccine (PCV13), was licensed for optional use in China. We will conduct a scoping review of the distribution of serotypes and antimicrobial resistance of Streptococcus pneumoniae in children aged under 5 years in China since the introduction of PCV13. We will obtain data from PubMed, the China National Knowledge Infrastructure (CNKI), and Wanfang Med Online. We will also review epidemiological data from WHO and the China Antimicrobial Surveillance Network (CHINET). Our analysis will include the condition of interest, the intervention, and the geographical region. All types of studies will be eligible for inclusion in the study database if they meet the inclusion criteria. This scoping review is intended to outline how S. pneumoniae serotypes are distributed, and it will map their antimicrobial resistance in children aged under 5 years in China. The results of this study will provide useful information on the impact of PCV13 in China.

Serotype distribution and antimicrobial resistance of Streptococcus pneumoniae causing invasive diseases in China: a meta-analysis

Background

To summarize information about invasive pneumococcal disease (IPD) among children in mainland China.

Methods

Sixteen eligible studies were included in this systematic review and the random effect model was used to estimate the pool prevalence of IPD.

Results

The most predominant serotypes circulating in children were 19F (27.7, 95% confidence interval (95% CI): 17.7–37.6%), 19A (21.2%, 16.4–26.1%), 14 (16.5%, 12.8–20.1%), 6B (8.6%, 5.2–10.8%) and 23F (7.3%, 5.2–9.5%). The serotype coverage of the available pneumococcal conjugate vaccines PCV7, PCV10, and PCV13 was 60.8% (52.5–69.4%), 65.1% (57.7–72.4%), and 90.0% (87.1–92.8%), respectively. The pooled antibiotic resistance rates of Streptococcus pneumoniae revealed a resistance to penicillin prevalence rate of 32.0% (12.1–51.9%). Approximately 94.4% (90.7–98.1%) and 92.3% (87.4–97.3%) of isolates were resistant to erythromycin and clindamycin. eBURST analysis revealed great diversity among isolates, with 102 sequence types (STs) for 365 isolates. The major predominant clonal complexes (CCs) were CC271 (43.6%, 159/365), CC876 (13.4%, 49/365), CC81 (5.2%, 19/365), and CC90 (4.1%, 15/365). Long-term and regional surveillance of S. pneumoniae is necessary.

Conclusions

Based on our pooled results showing that PCV13 coverage of the reported serotypes was 90% and that most serotypes contributed to the distribution of antibiotic-resistant isolates, implementation of PCV13 into the Chinese Expanded Program on Immunizations (EPI) would achieve health benefits in Chinese children.

Etiology of acute otitis media and phenotypic-molecular characterization of Streptococcus pneumoniae isolated from children in Liuzhou, China

Background

The etiology and epidemiology of acute otitis media (AOM) are poorly understood in China. This study aimed to describe the etiology of AOM and the phenotypic and molecular characteristics of AOM-causing Streptococcus pneumoniae (S.pneumoniae) recovered from Chinese children.

Methods

A retrospective study was conducted to enrol patients younger than 18 years diagnosed as AOM. Middle ear fluid specimens were collected then cultured for bacterial pathogens. All S.pneumoniae isolates were tested for antibiotic susceptibility, serotypes, virulence genes, antibiotic resistant determinants and sequence types.

Results

The dominant otopathogen among AOM children was S.pneumoniae (54.4%). Among S.pneumoniae isolates, there were 97.3, 97.3 and 75.7% isolates resistant to erythromycin, tetracycline and trimethoprim-sulfamethoxazole, respectively. There was 72.8% S.pneumoniae with multidrug resistance. The dominant sequence types (STs) were ST271 and ST320, whereas the prevailing serotypes were 19F and 19A. The 7-valent and 13-valent pneumococcal conjugate vaccine (PCV) coverage among AOM children were 73.0 and 94.6%, respectively. Additionally, we found that CC271 expressed more of mef(A/E) (P < 0.001), pspA (P = 0.022) and sipA (P < 0.001) than non-CC271 isolates.

Conclusion

The high prevalence of international multidrug-resistant clone (Taiwan^19F-14) in China necessitates continued dedication to expand PCV13 immunization and better control of antibiotic use in China.

The health and economic impact of vaccination with 7-valent pneumococcal vaccine (PCV7) during an annual influenza epidemic and influenza pandemic in China

BACKGROUND

China has experienced several severe outbreaks of influenza over the past century: 1918, 1957, 1968, and 2009. Influenza itself can be deadly; however, the increase in mortality during an influenza outbreak is also attributable to secondary bacterial infections, specifically pneumococcal disease. Given the history of pandemic outbreaks and the associated morbidity and mortality, we investigated the cost-effectiveness of a PCV7 vaccination program in China from the context of typical and pandemic influenza seasons.

METHODS

A decision-analytic model was employed to evaluate the impact of a 7-valent pneumococcal vaccine (PCV7) infant vaccination program on the incidence, mortality, and cost associated with pneumococcal disease during a typical influenza season (15% flu incidence) and influenza pandemic (30% flu incidence) in China. The model incorporated Chinese data where available and included both direct and indirect (herd) effects on the unvaccinated population, assuming a point in time following the initial introduction of the vaccine where the impact of the indirect effects has reached a steady state, approximately seven years following the implementation of the vaccine program. Pneumococcal disease incidence, mortality, and costs were evaluated over a one year time horizon. Healthcare costs were calculated using a payer perspective and included vaccination program costs and direct medical expenditures from pneumococcal disease.

RESULTS

The model predicted that routine PCV7 vaccination of infants in China would prevent 5,053,453 cases of pneumococcal disease and 76,714 deaths in a single year during a normal influenza season.The estimated incremental-cost-effectiveness ratios were ¥12,281 (US$1,900) per life-year saved and ¥13,737 (US$2,125) per quality-adjusted-life-year gained. During an influenza pandemic, the model estimated that routine vaccination with PCV7 would prevent 8,469,506 cases of pneumococcal disease and 707,526 deaths, and would be cost-saving.

CONCLUSIONS

Routine vaccination with PCV7 in China would be a cost-effective strategy at limiting the negative impact of influenza during a typical influenza season. During an influenza pandemic, the benefit of PCV7 in preventing excess pneumococcal morbidity and mortality renders a PCV7 vaccination program cost-saving.

Etiology and epidemiology of children with acute otitis media and spontaneous otorrhea in Suzhou, China

BACKGROUND

There are scare data about bacterial etiology and the antibiotic susceptibility, serotype distribution and molecular characteristics of pneumococci in children with acute otitis media (AOM) in China.

METHODS

A prospective study was conducted in Suzhou University Affiliated Children's Hospital. All children under 18 years of age diagnosed as AOM and with spontaneous otorrhea were offered enrollment, and collection of middle ear fluid was then cultured for bacterial pathogens. The antibiotic susceptibility, serotypes, macrolide resistance genes and sequence types of Streptococcus pneumoniae strains were identified.

RESULTS

From January 2011 to December 2013, a total of 229 cases of AOM with spontaneous otorrhea were identified; of these, 159 (69.4%) middle ear fluid specimens were tested positive for bacterial pathogens. The leading cause was S. pneumoniae (47.2%), followed by Staphylococcus aureus (18.8%) and Haemophilus influenzae (7.4%). The antibiotic resistance rates of S. pneumoniae isolates to erythromycin were 99.1%, and the nonsusceptible rate to penicillin was 54.6%. The most common serotypes identified were 19A (45.1%) and 19F (35.4%). The coverage against PCV7 serotypes for this outcome was 56.1% and of PCV13 was 97.6%. The macrolide resistance was mainly mediated by both ermB and mefA/E genes (88.6%). The CC271 was the major clonal complex identified.

CONCLUSIONS

S. pneumoniae was a leading cause for AOM in children in Suzhou, China. Antibiotics resistance rates of S. pneumoniae were high and mainly due to the spread of CC271 clonal complex.