Febrile Seizures and Measles-Containing Vaccines in China: A Self-Controlled Case Series Study

A feasibility assessment of real-world data capabilities for monitoring vaccine safety and effectiveness in China: Human papillomavirus vaccination in the Yinzhou district as a use case

BACKGROUND

Real-world data (RWD) are increasingly used to generate real-world evidence (RWE) of vaccine safety and effectiveness for regulatory purposes. Assessing feasibility of using RWD sources prior to implementing observational studies is recommended. As a use case, we described the process and findings of a feasibility assessment to identify reliable and relevant data sources for monitoring the safety and effectiveness of the AS04-HPV-16/18 human papillomavirus (HPV) vaccine in China.

METHODS

Iterative multi-step process: (1) targeted literature review and data source mapping; (2) expert opinion from national RWD experts; (3) survey to evaluate the identified data source operational infrastructure; and (4) continuous appraisal of published studies using the identified data source.

RESULTS

The Yinzhou Regional Health Information Platform (YRHIP) was identified as a data source of main interest, based on its large population coverage, high cervical cancer screening rates, and availability of adult electronic immunization records. Field meetings with national RWD experts confirmed its suitability for post-authorization vaccine studies. Survey results showed that exposure data and relevant safety and effectiveness endpoints were recorded and linkable at the individual level across the platform. Iterative appraisal of emerging evidence from the literature corroborated these findings.

CONCLUSIONS

This feasibility assessment indicates that the YRHIP has the capacity to capture demographic, exposure, outcome and other data required to generate RWE on HPV vaccine safety and effectiveness in China. Studies using the YRHIP to monitor the AS04-HPV-16/18 vaccine in routine use building on this feasibility assessment are ongoing.

Diagnostic validation and development of an algorithm for identification of intussusception in children using electronic health records of Ningbo city in China

BACKGROUND

Monitoring the risk of intussusception after the introduction of rotavirus vaccines is recommended by the World Health Organization (WHO). Although the validity of intussusception monitoring using electronic health records (EHRs) has been confirmed previously, no similar studies have been conducted in China. We aimed to verify the diagnosis and determine an algorithm with the best performance for identification of intussusception using Chinese EHR databases.

RESEARCH DESIGN AND METHODS

Using the Regional Health Information Platform in Ningbo, patients aged 0-72 months from 2015 to 2021 with any related visits for intussusception were included. The algorithms were based on diagnostic codes or keywords in different clinical scenarios, and their performance was evaluated with positive predictive value (PPV) and sensitivity in line with the Brighton guidelines.

RESULTS

Brighton level 1 intussusception was confirmed in 2958 patients with 3246 episodes. Fine-tuned algorithms combining the appearance of the relevant ICD-10 codes or the Chinese keyword 'Chang Tao' in any diagnostic reports with the results of enema treatments or related surgeries showed the highest sensitivity, while the highest PPV was obtained by further criteria based on typical radiographic appearances.

CONCLUSION

Intussusception could be identified and validated internally using EHRs in Ningbo.

No association between enterovirus 71 (EV71) vaccination and risk of febrile seizures: a population-based near real-time surveillance study

BACKGROUND

Since 2016, vaccines against enterovirus 71 (EV71) infection have been approved for use in China. Reports to the national passive surveillance system raised concerns about febrile seizures (FS) after EV71 vaccination. Rapid safety assessment of this novel vaccine is a public health priority. The objective was to assess risks of FS following EV71 vaccination in China.

METHODS

We used data from a Regional Health Information Platform in Ningbo. The exposed population was children aged 6-71 months who received any dose of EV71 vaccine from 1 January 2016 to 31 December 2019. We implemented a multilayered approach to actively monitor FS following EV71 vaccination that included near real-time surveillance using two complementary sequential designs and further signal evaluation performing self-controlled risk interval (SCRI) analyses.

RESULTS

A total of 330,668 EV71 doses were administered to the study population. During 157 weeks of sequential analyses, no statistically increased risks were detected, when compared with the self-matched control interval or the background risk. Further SCRI analyses confirmed no associations between EV71 vaccination and FS (adjusted incidence rate ratio: 1.04, 95% CI: 0.75 to 1.43).

CONCLUSIONS

Our results reassured the safety of FS after EV71 vaccination using postlicensure data for the first time.