Announcing a new article publication for Zoonoses journal. This study investigates the effectiveness of inactivated COVID-19 vaccines against the Delta variant.
The authors of this article performed a retrospective cohort study of close contacts of people with laboratory-confirmed SARS-CoV-2 infections in Hunan province, China, from July to August 2021. Mixed-effect logistic regression was used to estimate vaccine effectiveness (VE), and analyze the effects of the vaccination status of index cases and the exposure risk level on VE estimation.
A total of 1,685 close contacts of 126 index cases were included; 835 (49.6%) had received two doses of inactivated vaccines, and the median interval between the 2nd dose and exposure was 48 days (IQR: 41 to 56 days). Full vaccination was defined as two doses at least 14 days before exposure. Adjusted VE estimates for full vaccination were 54.8% (95% CI: 7.7 to 77.9) and 68.4% (95% CI: 8.5 to 89.1) against symptomatic and moderate-to-severe COVID-19, respectively. VE for inactivated vaccines was difficult to observe if index cases had been fully vaccinated. The estimated VE with respect to infection protection was lower among household than non-household contacts.
Complete primary immunization of two-dose inactivated COVID-19 vaccines protected against SARS-CoV-2 Delta variant infection. Infection risk was higher among vaccinated household contacts than vaccinated non-household contacts.
Article reference: Xuemei Yan, Zhihui Dai and Qianhui Wu et al. Effectiveness of Inactivated SARS-CoV-2 Vaccines During a Delta Variant Outbreak in Hunan Province, China: A Retrospective Cohort Study. Zoonoses. Vol. 2(1). DOI: 10.15212/ZOONOSES-2022-0020
Keywords: SARS-CoV-2, Delta, inactivated vaccine, vaccine effectiveness, close contact
Zoonoses is fully open access journal for research scientists, physicians, veterinarians, and public health professionals working on diverse disciplinaries of zoonotic diseases.
Zoonoses is now open for submissions; articles can be submitted online at https://mc04.manuscriptcentral.com/zoonoses
Please visit https://zoonoses-journal.org/ to learn more about the journal.
Editorial Board: https://zoonoses-journal.org/index.php/editorial-board/
Zoonoses is available on ScienceOpen (https://www.scienceopen.com/search#collection/839df240-327f-47dd-b636-9b728dff9700).
There are no author submission or article processing fees.
Follow Zoonoses on Twitter @ZoonosesJ; Facebook (https://www.facebook.com/Zoonoses-Journal-100462755574114 ) and LinkedIn (https://www.linkedin.com/company/zoonoses/)