Real-World Effectiveness of Primary Series and Booster Doses of Inactivated Coronavirus Disease 2019 Vaccine Against Omicron BA.2 Variant Infection in China: A Retrospective Cohort Study.

BACKGROUND: China has been using inactivated coronavirus disease 2019 (COVID-19) vaccines as primary series and booster doses to protect the population from severe to fatal COVID-19. We evaluated primary and booster vaccine effectiveness (VE) against Omicron BA.2 infection outcomes. METHODS: This was a 13-province retrospective cohort study of quarantined close contacts of BA.2-infected individuals. Outcomes were BA.2 infection, COVID-19 pneumonia or worse, and severe/critical COVID-19. Absolute VE was estimated by comparison with an unvaccinated group. RESULTS: There were 289 427 close contacts ≥3 years old exposed to Omicron BA.2 cases; 31 831 turned nucleic acid amplification test-positive during quarantine, 97.2% with mild or asymptomatic infection, 2.6% with COVID-19 pneumonia, and 0.15% with severe/critical COVID-19. None died. Adjusted VE (aVE) against any infection was 17% for primary series and 22% when boosted. Primary series aVE in adults >18 years was 66% against COVID-19 pneumonia or worse and 91% against severe/critical COVID-19. Booster dose aVE was 74% against pneumonia or worse, and 93% against severe/critical COVID-19. CONCLUSIONS: Inactivated COVID-19 vaccines provided modest protection from infection, very good protection against pneumonia, and excellent protection against severe/critical COVID-19. Booster doses are necessary to provide strongest protection.

Epidemiological Characteristics of Notifiable Infectious Diseases among Foreign Cases in China, 2004-2017.

OBJECTIVE: We aimed to assess the features of notifiable infectious diseases found commonly in foreign nationals in China between 2004 and 2017 to improve public health policy and responses for infectious diseases. METHODS: We performed a descriptive study of notifiable infectious diseases among foreigners reported from 2004 to 2017 in China using data from the Chinese National Notifiable Infectious Disease Reporting System (NNIDRIS). Demographic, temporal-spatial distribution were described and analyzed. RESULTS: A total of 67,939 cases of 33 different infectious diseases were reported among foreigners. These diseases were seen in 31 provinces of China and originated from 146 countries of the world. The infectious diseases with the highest incidence number were human immunodeficiency virus (HIV) of 18,713 cases, hepatitis B (6,461 cases), hand, foot, and mouth disease (6,327 cases). Yunnan province had the highest number of notifiable infectious diseases in foreigners. There were different trends of the major infectious diseases among foreign cases seen in China and varied among provinces. CONCLUSIONS: This is the first description of the epidemiological characteristic of notifiable infectious diseases among foreigners in China from 2004 to 2017. These data can be used to better inform policymakers about national health priorities for future research and control strategies.

Prevalence of and risk factors for tuberculosis among healthcare workers in Chinese tuberculosis facilities.

BACKGROUND: China is one of 22 countries with a high tuberculosis (TB) burden in the world. Healthcare workers (HCWs) have a high risk of contracting Mycobacterium tuberculosis infection due to insufficient infection control practices. We conducted a cross-sectional study to explore the prevalence of TB and its associated risk factors among HCWs in Chinese TB facilities. METHODS: Two hundred and forty-one TB facilities employing a total of 9663 HCWs were selected from 12 provinces in China to represent healthcare settings at the provincial, prefectural, and county levels. Structured questionnaires were used to collect information on TB infection control practices and HCWs in those facilities. Data was double entered into EpiData 3.1; TB prevalence and associated risk factors were analyzed using SPSS 21.0 with bivariate and multivariate regression models. RESULTS: The results showed that 71 HCWs had been diagnosed with TB, accounting for a prevalence of 760/100 000. The multivariate analysis showed that associated risk factors included belonging to the age group of 51 years and above (aOR: 6.17, 95% CI: 1.35-28.28), being a nurse (aOR = 3.09, 95% CI: 1.15-8.32), implementation of 0-9 items of management measures (aOR = 2.57, 95% CI: 1.37-4.80), and implementation of 0-1 items of ventilation measures (aOR = 2.42, 95% CI: 1.31-4.47). CONCLUSION: This was the first national large sampling survey on TB prevalence among HCWs in China. It was found that the implementation of TB infection control practices in some facilities was poor. The TB prevalence in HCWs was higher than that in the general population. Therefore, TB infection control practices in Chinese medical facilities should be strengthened.