Increasing vaccination coverage: The school entry vaccination record check program in Guizhou Province China, 2003-2018.

BACKGROUND: Guizhou Province of China implements a vaccination program specifying that children's vaccination records are to be checked upon entry to kindergarten and primary school; children missing one or more recommended vaccinations are to be offered the missed vaccinations; school-level vaccination coverage levels are assessed at the time of school enrollment and six months later to monitor compliance rates. METHODS: We obtained the number of doses of each vaccine in the national immunization schedule that were administered before and six months after kindergarten and school enrollment and reported to Guizhou Province during 2004 through 2018. We determined temporal trends in coverage of the second dose of measles-containing vaccine (MCV2) and other vaccines, incidence of measles, and number of school-based measles outbreaks. RESULTS: MCV2 coverage at kindergarten entry increased from 53% in 2004 to 98% in 2018. Among children missing one or more vaccinations, the six-month catch-up rate of MCV2 increased from 80% in 2004 to 99% in 2018. Among primary school children, coverage of MCV2 and other recommended vaccines had similar increases. The annual incidence of measles among Guizhou's total population declined from 280 per million in 2003 to 0.3 per million in 2018. There have been no measles outbreaks in kindergartens or schools since 2015. CONCLUSIONS: Checking vaccination record at kindergartens and primary schools and providing necessary catch-up vaccination was associated with increased coverage of measles and other vaccines, lower incidence of measles, and an apparent end to school-based measles outbreaks. Guizhou's experience of checking vaccination records at school enrollment led to implementation of this strategy in other provinces. In 2019, the kindergarten and school entry vaccination record check program was incorporated into China's national vaccine law.

Introduction of Inactivated Poliovirus Vaccine and Impact on Vaccine-Associated Paralytic Poliomyelitis - Beijing, China, 2014-2016.

When included in a sequential polio vaccination schedule, inactivated polio vaccine (IPV) reduces the risk for vaccine-associated paralytic poliomyelitis (VAPP), a rare adverse event associated with receipt of oral poliovirus vaccine (OPV). During January 2014, the World Health Organization (WHO) recommended introduction of at least 1 IPV dose into routine immunization schedules in OPV-using countries (1). The Polio Eradication and Endgame Strategic Plan 2013-2018 recommended completion of IPV introduction in 2015 and globally synchronized withdrawal of OPV type 2 in 2016 (2). Introduction of 1 dose of IPV into Beijing's Expanded Program on Immunization (EPI) on December 5, 2014 represented China's first province-wide IPV introduction. Coverage with the first dose of polio vaccine was maintained from 96.2% to 96.9%, similar to coverage with the first dose of diphtheria and tetanus toxoids and pertussis vaccine (DTP) (96.5%-97.2%); the polio vaccine dropout rate (the percentage of children who received the first dose of polio vaccine but failed to complete the series) was 1.0% in 2015 and 0.4% in 2016. The use of 3 doses of private-sector IPV per child decreased from 18.1% in 2014, to 17.4% in 2015, and to 14.8% in 2016. No cases of VAPP were identified during 2014-2016. Successful introduction of IPV into the public sector EPI program was attributed to comprehensive planning, preparation, implementation, robust surveillance for adverse events after immunization (AEFI), and monitoring of vaccination coverage. This evaluation provided information that helped contribute to the expansion of IPV use in China and in other OPV-using countries.

Introduction of inactivated poliovirus vaccine leading into the polio eradication endgame strategic plan; Hangzhou, China, 2010-2014.

BACKGROUND: China's Expanded Program on Immunization (EPI) has provided 4 doses of oral poliovirus vaccine (OPV) since the 1970s. Inactivated poliovirus vaccine (IPV) became available in 2010 in Hangzhou as a private-sector, parent-chosen alternative to OPV. In 2015, WHO recommended that countries with all-OPV vaccination schedules introduce at least one dose of IPV, to mitigate risk associated with the withdrawal of type 2 OPV. We analyzed polio vaccine coverage and utilization in Hangzhou to determine patterns of IPV use and the occurrence of vaccine-associated paralytic polio (VAPP) in the various patterns identified. METHODS: Children born between 2010 and 2014 and registered in Hangzhou's Immunization Information System (HZIIS) were included. VAPP cases were detected through the acute flaccid paralysis surveillance system. We used descriptive epidemiological methods to determine IPV and OPV usage patterns and VAPP occurrence. RESULTS: HZIIS data from 566,894 children were analyzed. Coverage levels of polio vaccine were greater than 92% for each birth cohort. Percentages of children using OPV-only, IPV-only, and IPV/OPV sequential schedules were 70.57%, 27.01% and 2.41%, respectively. IPV-only schedule utilization increased by birth cohort regardless of geographical area or whether the child was locally-born. The highest use of an all-IPV schedule (79.85%) was among urban, locally-born children in the 2014 birth cohort. Five VAPP cases were identified during the study years; all cases occurred following the first polio vaccine dose, which was always OPV for the cases. Type 2 vaccine virus was isolated from 2 VAPP cases, and type 2 and type 3 vaccine virus was isolated from one VAPP case. The incidence of VAPP in the 2010-2014 birth cohorts was 3.76 per 1million doses of OPV. CONCLUSION: Children in Hangzhou had high polio vaccination coverage. IPV-only schedule use increased by year, and was highest in urban areas among locally-born children. All cases of VAPP were associated with the first dose of OPV.

Accelerating measles elimination and strengthening routine immunization services in Guizhou Province, China, 2003-2009.

BACKGROUND: To develop a successful model for accelerating measles elimination in poor areas of China, we initiated a seven-year project in Guizhou, one of the poorest provinces, with reported highest measles incidence of 360 per million population in 2002. METHODS: Project strategies consisted of strengthening routine immunization services, enforcement of school entry immunization requirements at kindergarten and school, conducting supplemental measles immunization activities (SIAs), and enhancing measles surveillance. We measured coverage of measles containing vaccines (MCV) by administrative reporting and population-based sample surveys, systematic random sampling surveys, and convenience sampling surveys for routine immunization services, school entry immunization, and SIAs respectively. We measured impact using surveillance based measles incidence. RESULTS: Routine immunization coverage of the 1st dose of MCV (MCV1) increased from 82% to 93%, while 2nd dose of MCV (MCV2) coverage increased from 78% to 91%. Enforcement of school entry immunization requirements led to an increase in MCV2 coverage from 36% on primary school entry in 2004 to 93% in 2009. Province-wide SIAs achieved coverage greater than 90%. The reported annual incidence of measles dropped from 200 to 300 per million in 2003 to 6 per million in 2009, and sustained at 0.9-2.2 per million in 2010-2013. CONCLUSIONS: This project found that a package of strategies including periodic SIAs, strengthened routine immunization, and enforcing school entry immunization requirements, was an effective approach toward achieving and sustaining measles elimination in less-developed area of China.

Expansion of syndromic vaccine preventable disease surveillance to include bacterial meningitis and Japanese encephalitis: evaluation of adapting polio and measles laboratory networks in Bangladesh, China and India, 2007-2008.

BACKGROUND: Surveillance for acute flaccid paralysis with laboratory confirmation has been a key strategy in the global polio eradication initiative, and the laboratory platform established for polio testing has been expanded in many countries to include surveillance for cases of febrile rash illness to identify measles and rubella cases. Vaccine-preventable disease surveillance is essential to detect outbreaks, define disease burden, guide vaccination strategies and assess immunization impact. Vaccines now exist to prevent Japanese encephalitis (JE) and some etiologies of bacterial meningitis. METHODS: We evaluated the feasibility of expanding polio-measles surveillance and laboratory networks to detect bacterial meningitis and JE, using surveillance for acute meningitis-encephalitis syndrome in Bangladesh and China and acute encephalitis syndrome in India. We developed nine syndromic surveillance performance indicators based on international surveillance guidelines and calculated scores using supervisory visit reports, annual reports, and case-based surveillance data. RESULTS: Scores, variable by country and targeted disease, were highest for the presence of national guidelines, sustainability, training, availability of JE laboratory resources, and effectiveness of using polio-measles networks for JE surveillance. Scores for effectiveness of building on polio-measles networks for bacterial meningitis surveillance and specimen referral were the lowest, because of differences in specimens and techniques. CONCLUSIONS: Polio-measles surveillance and laboratory networks provided useful infrastructure for establishing syndromic surveillance and building capacity for JE diagnosis, but were less applicable for bacterial meningitis. Laboratory-supported surveillance for vaccine-preventable bacterial diseases will require substantial technical and financial support to enhance local diagnostic capacity.

Post-marketing surveillance of live-attenuated Japanese encephalitis vaccine safety in China.

Japanese encephalitis (JE) is the most severe form of viral encephalitis in Asia and no specific treatment is available. Vaccination provides an effective intervention to prevent JE. In this paper, surveillance data for adverse events following immunization (AEFI) related to SA-14-14-2 live-attenuated Japanese encephalitis vaccine (Chengdu Institute of Biological Products) was presented. This information has been routinely generated by the Chinese national surveillance system for the period 2009-2012. There were 6024 AEFI cases (estimated reported rate 96.55 per million doses). Most common symptoms of adverse events were fever, redness, induration and skin rash. There were 70 serious AEFI cases (1.12 per million doses), including 9 cases of meningoencephalitis and 4 cases of death. The post-marketing surveillance data add the evidence that the Chengdu institute live attenutated vaccine has a reasonable safety profile. The relationship between encephalitis and SA-14-14-2 vaccination should be further studied.

[Validation on the elimination of neonatal tetanus programs through Lot Quality Assurance-Cluster Sample Survey in China].

OBJECTIVE: Field surveys were performed under WHO recommended validation procedures, using the Lot Quality Assurance-Cluster Sample(LQA-CS)method to validate the elimination status regarding neonatal tetanus in China. METHODS: LQA-CS surveys were conducted in two areas under the highest risk of neonatal tetanus-Jiangmen prefecture in Guangdong and Hechi in Guangxi. Random sampling method was conducted on 96 survey clusters in each prefecture with 12 eligible live births(live birth born one year before the survey)for each cluster, by trained investigators. RESULTS: There were 1 153 eligible live births from 23 465 families surveyed in Jiangmen and 1 152 eligible live births from 21 623 families being studied in Hechi. All the indices on quality control were strictly followed. There was no neonatal tetanus case which met the criteria of neonatal elimination found in either of the areas. Data showed that neonatal tetanus had been eliminated in both Jiangmen and Hechi cities. CONCLUSION: Since both Jiangmen and Hechi were cities having the highest-risk in China, it was most likely that neonatal tetanus had also been eliminated in other prefectures at lower risk. Elimination programs on MNT was therefore considered validate in China when the study was carried out. However, the achievements needed to be maintained.

Population-based surveillance for bacterial meningitis in China, September 2006-December 2009.

During September 2006-December 2009, we conducted active population and sentinel laboratory-based surveillance for bacterial meningitis pathogens, including Streptococcus pneumoniae, Neisseria meningitidis, and Haemophilus influenzae type b, in 4 China prefectures. We identified 7,876 acute meningitis and encephalitis syndrome cases, including 6,388 among prefecture residents. A total of 833 resident cases from sentinel hospitals met the World Health Organization case definition for probable bacterial meningitis; 339 of these cases were among children <5 years of age. Laboratory testing confirmed bacterial meningitis in 74 of 3,391 tested cases. The estimated annual incidence (per 100,000 population) of probable bacterial meningitis ranged from 1.84 to 2.93 for the entire population and from 6.95 to 22.30 for children <5 years old. Active surveillance with laboratory confirmation has provided a population-based estimate of the number of probable bacterial meningitis cases in China, but more complete laboratory testing is needed to better define the epidemiology of the disease in this country.

Improving hepatitis B vaccine timely birth dose coverage: lessons from five demonstration projects in China, 2005-2009.

BACKGROUND: Delivery of a timely (within 24h) hepatitis B vaccine birth dose (TBD) is essential to prevent the long-term complications of hepatitis B virus (HBV) infection. China made substantial progress in hepatitis B immunization coverage, however, in 2004, TBD coverage was lower in Western, poorer provinces. METHODS: We reviewed five demonstration projects for the promotion of TBD in rural counties in Qinghai, Gansu and Ningxia. Interventions consisted of (1) work to increase TBD coverage in hospitals, including training of health-care workers, (2) information, education and communication [IEC] with the population and (3) micro-plans to deliver TBD for home births. We evaluated outcome through measuring TBD coverage for home and hospital births. RESULTS: These projects were implemented in the context of national efforts to promote institutional deliveries that lead to increases ranging from 10% to 17% to reach 43-97% proportion of institutional births at the end of the projects. Among institutional births, TBD coverage increased by 2% to 13% to reach post implementation coverage ranging from 98% to 100%. Among home births, TBD coverage increased by 7% to 56% to reach post implementation coverage ranging from 29% to 88%. Overall, TBD coverage increased by 4% to 36% to reach post implementation coverage ranging from 82% to 88%. CONCLUSIONS: Demonstration projects based on combined interventions increased TBD coverage. Increases in institutional births amplified the results obtained. Use of standardized indicators for such projects would facilitate evaluation and identify intervention components that are most effective.

Review of hepatitis B surveillance in China: improving information to frame future directions in prevention and control.

BACKGROUND: As the WHO verified that China reached the target of 1% prevalence of chronic hepatitis B infection among children targeted by universal hepatitis B immunization of newborns, the country considered new options for hepatitis B prevention and control. We reviewed hepatitis B surveillance in the broader context of viral hepatitis surveillance to propose recommendations to improve the system. METHODS: We described surveillance for viral hepatitis in China with a specific focus on hepatitis B. We assessed critical attributes of the system, including data quality, predictive positive value and usefulness. RESULTS: While remarkable progress in hepatitis B immunization of infants and children has likely almost eliminated transmission in younger age groups, reported rates of hepatitis B increased steadily in China between 1990 and 2008, probably because of a failure to distinguish acute from chronic infections. Elements that prevented a clearer separation between acute and chronic cases included (1) missed opportunity to report cases accurately among clinicians, (2) low availability and use of tests to detect IgM against the hepatitis B core antigen (IgM anti-HBc) and (3) lack of systems to sort, manage and analyze surveillance data. CONCLUSIONS: To improve hepatitis B surveillance, China may consider (1) training clinicians to diagnose acute cases and to use IgM anti-HBc to confirm them, (2) improving access and use of validated IgM anti-HBc tests and (3) developing data management and analysis techniques that sort out acute from chronic cases.

[The method and efficacy for screening neonatal tetanus in high risk areas in China].

OBJECTIVES: To establish a method for screening neonatal tetanus (NT) in high risk areas in China using multi-sources data. METHODS: We adopted six NT-related indicators from National Notifiable Disease Report System (NNDRS) and National Maternal and Child Health Annual Report System, to calculate weighted high-risk score at prefecture level in 2010 and 2011. And we selected the top 30 high risk cities, and compared the scores with the actual NT incidence ranking and WHO scoring. RESULTS: The highest areas distributed in the Southwest of China with poor and minority population, and the Southeast part with high density of migrants. In the leading 30 prefectures with high score between the methods of weighted high-risk scoring and reported NT incidence ranking, there were 8 different. In comparison of the results of the methods of weighed high-risk scoring and WHO scoring, 276 prefectures in 340 distributed were divided into the same ranking groups, with Kappa coefficient 0.56 (P < 0.01). The Chi-Square association coefficient was 0.74 (P < 0.01), which showed a high correlation. But there were 10 different prefectures in the leading 36 prefectures between the two methods. CONCLUSION: The weighted scoring method included several possible factors influencing NT incidence and took their weights into consideration. Thereby, compared with WHO scoring method, this method could be more appropriate for the reality in China.

An economic evaluation of the use of Japanese encephalitis vaccine in the expanded program of immunization of Guizhou province, China.

BACKGROUND: Historically, China's Japanese encephalitis vaccination program was a mix of household purchase of vaccine and government provision of vaccine in some endemic provinces. In 2006, Guizhou, a highly endemic province in South West China, integrated JE vaccine into the provincial Expanded Program on Immunization (EPI); later, in 2007 China fully integrated 28 provinces into the national EPI, including Guizhou, allowing for vaccine and syringe costs to be paid at the national level. We conducted a retrospective economic analysis of JE integration into EPI in Guizhou province. METHODS: We modeled two theoretical cohorts of 100,000 persons for 65 years; one using JE live-attenuated vaccine in EPI (first dose: 95% coverage and 94.5% efficacy; second dose: 85% coverage and 98% efficacy) and one not. We assumed 60% sensitivity of surveillance for reported JE rates, 25% case fatality, 30% chronic disability and 3% discounting. We reviewed acute care medical records and interviewed a sample of survivors to estimate direct and indirect costs of illness. We reviewed the EPI offices expenditures in 2009 to estimate the average Guizhou program cost per vaccine dose. RESULTS: Use of JE vaccine in EPI for 100,000 persons would cost 434,898 US$ each year (46% of total cost due to vaccine) and prevent 406 JE cases, 102 deaths, and 122 chronic disabilities (4554 DALYs). If we ignore future cost savings and only use EPI program cost, the program would cost 95.5 US$/DALY, less than China Gross Domestic Product per capita in 2009 (3741 US$). From a cost-benefit perspective taking into account future savings, use of JE vaccine in EPI for a 100,000-person cohort would lead to savings of 1,591,975 US$ for the health system and 11,570,989 US$ from the societal perspective. CONCLUSIONS: In Guizhou, China, use of JE vaccine in EPI is a cost effective investment. Furthermore, it would lead to savings for the health system and society.

Measles resurgence associated with continued circulation of genotype H1 viruses in China, 2005.

Measles morbidity and mortality decreased significantly after measles vaccine was introduced into China in 1965. From 1995 to 2004, average annual measles incidence decreased to 5.6 cases per 100,000 population following the establishment of a national two-dose regimen. Molecular characterization of wild-type measles viruses demonstrated that genotype H1 was endemic and widely distributed throughout the country in China during 1995-2004. A total of 124,865 cases and 55 deaths were reported from the National Notifiable Diseases Reporting System (NNDRS) in 2005, which represented a 69.05% increase compared with 2004. Over 16,000 serum samples obtained from 914 measles outbreaks and the measles IgM positive rate was 81%. 213 wild-type measles viruses were isolated from 18 of 31 provinces in China during 2005, and all of the isolates belonged to genotype H1. The ranges of the nucleotide sequence and predicted amino acid sequence homologies of the 213 genotype H1 strains were 93.4%-100% and 90.0%-100%, respectively. H1-associated cases and outbreaks caused the measles resurgence in China in 2005. H1 genotype has the most inner variation within genotype, it could be divided into 2 clusters, and cluster 1 viruses were predominant in China throughout 2005.

Feasibility study of enforcing immunization certificate check before primary school or kindergarten enrollment in Guizhou Province, China.

OBJECTIVE: To study the feasibility of enforcing immunization certificate check before children enroll in primary schools or kindergartens in Guizhou Province. METHODS: Quantitative and qualitative studies were conducted. The multi-stage and cluster sampling approach was adopted for the quantitative part of the study. A questionnaire was designed and 996 children and their keepers were interviewed. Principals, doctors or teachers of the primary schools, directors and child care nurses of kindergarten, and staff of immunization agencies were invited to take part in 12 focus group discussions; meanwhile, face-to-face individual in-depth interviews with 16 officials of the Health, Education and Governmental Departments at various levels were conducted. RESULTS: The total number of subjects was 996. 16.7% of the children in the study completed all the procedures of the National Immunization Programme. 34.3% of them had immunization certificates while the remainder 44.7% registered in immunization agencies. Factors, including the migrant children, doubt about vaccine efficiency, mother's occupation and educational background, knowledge of the National Immunization Programme on targeted vaccines, played an important role in obtaining or not immunization certificates. 95% of the keepers interviewed thought the immunization certificates were useful; 94.8% of them considered the check was critical while only 3.6% of them thought it unnecessary. The first reason from those who found it unnecessary was that they feared that repeated immunization might affect their children's health. The second reason was the cost of immunization, which some of them could not afford to pay. However, the Health Department expressed a favorable attitude to the checking scheme. Though the Education Department agreed that the scheme was essential, they worried that it would affect the enrollment rate. CONCLUSION: In spite of the difficulty in administering immunization certificate check, the effort would be rewarding for raising the immunization coverage rate among the children in Guizhou Province.

An outbreak of poliomyelitis caused by type 1 vaccine-derived poliovirus in China.

BACKGROUND: In May-July 2004, type 1 vaccine-derived poliovirus (VDPV) was isolated from 2 case patients with polio and a contact of a third case patient in Guizhou Province. METHODS: We conducted a field investigation of the outbreak, characterized outbreak isolates, and retrospectively reviewed national polio surveillance data for other VDPVs. RESULTS: Case patients were unimmunized children, 0.9-3.2 years old, living in 2 villages 40 km apart. Immunization coverage in the affected villages was very low. Isolates differed from the Sabin 1 type by 9-11 VP1 nucleotides (1.0%-1.2%); which indicated, on the basis of known rates of mutation of Sabin strains, that they had been circulating for <1 year. A province-wide immunization response targeting all children <5 years old was initiated in August, and the strain has not been isolated since. During 1997-2004, 10 VDPV strains (5 of type 2, 3 of type 1, and 2 of type 3) were isolated from >50,000 children with acute flaccid paralysis and their contacts; 8 (80%) were found in southern provinces, and 9 (90%) spontaneously disappeared. CONCLUSION: This is the first polio outbreak in China in over a decade and the first due to VDPV. The short duration of circulation demonstrates the rapidity with which attenuated Sabin strains can revert to a wild phenotype. One to two VDPVs have been identified each year, primarily in densely populated subtropical regions of southern China. This outbreak highlights the need to consider risks of paralysis from vaccine-derived strains in development of national poliomyelitis immunization policy.