Measles vaccine coverage estimates in an outbreak three years after the nation-wide campaign in China: implications for measles elimination, 2013.

BACKGROUND: China is approaching measles elimination, but indigenous measles still circulates. County L in China has reported measles-containing vaccine (MCV) coverage rates >95% since 2000. Despite high reported coverage, a large measles outbreak occurred among young children in L County. We measured MCV coverage using 5 different methods during an investigation on this outbreak and compared our estimates with reported rates. METHODS: Reported coverage rates are determined by aggregating clinic-based data across the county: doses administered in each clinic divided by the number of children registered in each clinic. Our methods estimated coverage for the 2010-2012 birth cohort, and were (1) administrative method: doses administered in clinics divided by the birth cohort recorded in the Statistical Year Book, (2) house-to-house convenience-sample survey of children living near cases, (3) vaccination clinic records review, (4) determination of a convenience sample of measles outbreak cases' vaccination statuses and using the field vaccine efficacy outbreak equation to estimate population coverage, and (5) a seroprevalence survey using a convenience sample of residual blood samples from hospitals. RESULTS: The measles outbreak totaled 215 cases, representing an incidence of 195.8 per million population. Our estimated MCV coverage rates were: (1) administrative method: 84.1%-87.0% for MCV1 and 80.3%-90.0% for MCV2, (2) in-house survey: 83.3% of 9-17 month children received MCV1, and 74.5% of 24-47 month children received MCV2, (3) clinic record review: 85.5% of 9-17 month children received MCV1, and 73.2% of 24-59 month children received MCV2, (4) field VE method: 83.6% of 9-47 month children received one or more MCV doses, and (5) serology: seropositive rates were <80% in the 12-17 and 18-23 month age cohorts. CONCLUSIONS: Compared with reported coverage >95%, our 5 coverage assessments all showed substantially lower coverage. China should evaluate guidelines for reporting vaccination coverage and identify feasible improvements to the assessment methods.

WHO Global Situational Alert System: a mixed methods multistage approach to identify country-level COVID-19 alerts.

BACKGROUND: Globally, since 1 January 2020 and as of 24 January 2023, there have been over 664 million cases of COVID-19 and over 6.7 million deaths reported to WHO. WHO developed an evidence-based alert system, assessing public health risk on a weekly basis in 237 countries, territories and areas from May 2021 to June 2022. This aimed to facilitate the early identification of situations where healthcare capacity may become overstretched. METHODS: The process involved a three-stage mixed methods approach. In the first stage, future deaths were predicted from the time series of reported cases and deaths to produce an initial alert level. In the second stage, this alert level was adjusted by incorporating a range of contextual indicators and accounting for the quality of information available using a Bayes classifier. In the third stage, countries with an alert level of 'High' or above were added to an operational watchlist and assistance was deployed as needed. RESULTS: Since June 2021, the system has supported the release of more than US$27 million from WHO emergency funding, over 450 000 rapid antigen diagnostic testing kits and over 6000 oxygen concentrators. Retrospective evaluation indicated that the first two stages were needed to maximise sensitivity, where 44% (IQR 29%-67%) of weekly watchlist alerts would not have been identified using only reported cases and deaths. The alerts were timely and valid in most cases; however, this could only be assessed on a non-representative sample of countries with hospitalisation data available. CONCLUSIONS: The system provided a standardised approach to monitor the pandemic at the country level by incorporating all available data on epidemiological analytics and contextual assessments. While this system was developed for COVID-19, a similar system could be used for future outbreaks and emergencies, with necessary adjustments to parameters and indicators.

[How to establish the monitoring and evaluation system in elimination stage of malaria in China: the experience from Malaria Indicator Survey system].

Malaria is one of the most important public health problems around the world. Most region of China has embarked a transition from interruption of malaria transmission to elimination. This paper summarizes the main function and construction, the key parts, and the advantages in national field work of Malaria Indicator Survey (MIS) system, indicates the difficulties of establishing a Monitoring and Evaluation (M&E) System in malaria elimination in China and draws lessons from the MIS.

Evaluation of a school entry immunization record check strategy in 4 counties of Ningxia and Hubei provinces, China.

China has a national requirement that children's vaccination status is to be checked upon entry to kindergarten and school; children who have missed vaccine doses are to be referred to vaccination clinics to receive the necessary vaccinations. Most provinces have Immunization Information Systems (IIS) that contain and manage vaccination records of children served by immunization clinics. We conducted an evaluation in Hubei and Ningxia provinces using IIS data to determine the effect of their school entry immunization record checking strategy (SECS) on vaccination coverage and rate of catch-up for selected vaccines. We selected two counties with well-functioning IISs from each province. Names and demographic information of children enrolled in 185 kindergartens and 125 primary school in 2016 were used to identify children in the IIS and obtain their vaccination records. We calculated vaccination coverage before and after implementation of the SECS and determined catch-up rates for 5 vaccines, of which 3 are given before 2 years of age and 2 are given after 2 years of age. Among the 20,215 newly-enrolled children, 75% were able to be matched with IIS records. Few children who had missed one or more doses of the 3 vaccines recommended in the first two years of life received catch-up doses after SECS. For vaccines scheduled after 2 years of age, there was a statistically significant (p < 0.05) coverage increase in both provinces following the school-entry record check. Among children who were age-eligible for the selected vaccines before SCES, the catch-up rate was <50%. SECS provides opportunities to identify incompletely vaccinated children, improve coverage, and remind families of school-age children about up-coming vaccinations; SECS has potential to improve completeness of IIS data and enrollment of children in immunization clinics. Evidence-based policy with implementation guidance and routine monitoring are necessary to improve China's school entry checking strategy.

Factors influencing the routine immunization status of children aged 2-3 years in China.

OBJECTIVES: To examine the factors associated with the routine immunization status of children aged 2-3 years in China for gaining a better understanding of the Expanded Program on Immunization and to provide evidence for formulating specific strategies to guide the allocation of health resources. METHODS: We analyzed data from 45095 children aged 2-3 years in the 2013 National Immunization Coverage Survey to identify the sociodemographic and provider-associated factors affecting the full immunization status of children. Univariate and multiple logistic regression analyses were performed. RESULTS: The immunization rate for children aged 2-3 years ranged from 95.9% (diphtheria and tetanus toxoid with pertussis vaccine, 4th dose) to 99.5% (Japanese encephalitis vaccine, 1st dose) and was 93.1% for full immunization. In terms of sociodemographic factors, male children [adjusted OR (AOR): 1.115; 95% confidence interval(CI):1.016-1.222], minority children (AOR: 1.632; 95% CI: 1.457-1.828), children of fathers with less than high school education (AOR: 1.577; 95% CI: 1.195-2.081), those born at home (AOR: 4.655; 95% CI: 3.771-5.746), those who immigrated from an adjacent county (AOR: 2.006; 95% CI: 1.581-2.546), and those living in urban-rural fringe areas (AOR: 1.807; 95% CI: 1.475-2.214) or mountainous areas (AOR: 1.615; 95% CI: 1.437-1.814) had significantly increased odds of not being fully immunized. In terms of provider-associated factors, administration of vaccines at home (AOR: 2.311; 95% CI: 1.316-4.059), household reminders (AOR: 2.292; 95% CI: 1.884-2.789), and travel time to vaccination providers of >40 minutes (AOR: 1.622; 95% CI: 1.309-2.010) were negatively associated with immunization rates. In addition, compared to 3-year-old years, 2-year-old children (AOR: 1.201; 95% CI: 1.094-1.318) were less likely to be fully immunized. CONCLUSIONS: All included factors except maternal education level and distance from home to vaccination providers significantly affected immunization rates. Appropriate reminders and accessibility of immunization services played key roles in improving the immunization status. More attention to high-risk groups identified in this study may reduce the disparities in routine childhood immunization in China.

Implementing the communication for development strategy to improve knowledge and coverage of measles vaccination in western Chinese immunization programs: a before-and-after evaluation.

BACKGROUND: Communication for Development (C4D) is a strategy promoted by the United Nations Children's Fund to foster positive and measurable changes at the individual, family, community, social, and policy levels of society. In western China, C4D activities have previously been conducted as part of province-level immunization programs. In this study, we evaluated the association of C4D with changes in parental knowledge of immunization services, measles disease, and measles vaccine, and changes in their children's measles vaccine coverage. METHODS: From April 2013 to April 2014, C4D activities were implemented as part of provincial immunization programs in the Inner Mongolia, Guangxi, Chongqing, Guizhou, Tibet, Shaanxi, Gansu, Ningxia, and Qinghai provinces. We used a before-and-after study design and employed face-to-face interviews to assess changes in parental knowledge and vaccination coverage. RESULTS: We surveyed 2 107 households at baseline and 2 070 households after 1 year of C4D activities. Following C4D, 95% of caregivers were aware of the vaccination record check requirement for entry into kindergarten and primary school; 80% of caregivers were aware that migrant children were eligible for free vaccination; more than 70% of caregivers knew that measles is a respiratory infectious disease; and 90% of caregivers knew the symptoms of measles. Caregivers' willingness to take their children to the clinic for vaccination increased from 51.3% at baseline to 67.4% in the post-C4D survey. Coverage of one-dose measles-containing vaccine (MCV) increased from 83.8% at baseline to 90.1% after C4D. One-dose MCV coverage was greater than 95% in the Guangxi, Shaanxi, and Gansu provinces. Two-dose MCV coverage increased from 68.5 to 77.6%. House-to-house communication was the most popular C4D activity among caregivers (91.6% favoring), followed by posters and educational talks (64.8 and 49.9% favoring). CONCLUSIONS: C4D is associated with increased caregiver knowledge about measles, increased willingness to seek immunization services for their children, and increased measles vaccination coverage. Tailored communication strategies based on insights gained from these analyses may be able to increase vaccination coverage in hard-to-reach areas. C4D should be considered for larger scale implementation in China.

Loss of confidence in vaccines following media reports of infant deaths after hepatitis B vaccination in China.

BACKGROUND: China reduced hepatitis B virus (HBV) infection by 90% among children under 5 years old with safe and effective hepatitis B vaccines (HepB). In December 2013, this success was threatened by widespread media reports of infant deaths following HepB administration. Seventeen deaths and one case of anaphylactic shock following HBV vaccination had been reported. METHODS: We conducted a telephone survey to measure parental confidence in HepB in eleven provinces at four points in time; reviewed maternal HBV status and use of HepB for newborns in birth hospitals in eight provinces before and after the event; and monitored coverage with hepatitis B vaccine and other programme vaccines in ten provinces. RESULTS: HepB from the implicated company was suspended during the investigation, which showed that the deaths were not caused by HepB vaccination. Before the event, 85% respondents regarded domestic vaccines as safe, decreasing to 26.7% during the event. During the height of the crisis, 30% of parents reported being hesitant to vaccinate and 18.4% reported they would refuse HepB. Use of HepB in the monitored provinces decreased by 18.6%, from 53 653 doses the week before the event to 43 688 doses during the week that Biokangtai HepB was suspended. Use of HepB within the first day of life decreased by 10% among infants born to HBsAg-negative mothers, and by 6% among infants born to HBsAg-positive mothers. Vaccine refusal and HepB birth dose rates returned to baseline within 2 months; confidence increased, but remained below baseline. CONCLUSIONS: The HBV vaccine event resulted in the suspension of a safe vaccine, which was associated with a decline of parental confidence, and refusal of vaccination. Suspension of a vaccine can lead to loss of confidence that is difficult to recover. Timely and credible investigation, accompanied by proactive outreach to stakeholders and the media, may help mitigate negative impact of future coincidental adverse events following immunization.