Emerging Microbes and Infections (Dec 2024)

Relative effectiveness of a heterologous booster dose with adenovirus type 5 vectored COVID-19 vaccine versus three doses of inactivated COVID-19 vaccine in adults during a nationwide outbreak of omicron predominance, in China: a retrospective, individually matched cohort-control study

  • Siyue Jia,
  • Zundong Yin,
  • Hongxing Pan,
  • Fuzhen Wang,
  • Xiaoqiang Liu,
  • Qing Wang,
  • Li Zhang,
  • Jihai Tang,
  • Hao Yang,
  • Jiangbo Du,
  • Zhiguo Wang,
  • Pengfei Jin,
  • Zhihang Peng,
  • Rong Tang,
  • Guodong Kang,
  • Xuewen Wang,
  • Simin Li,
  • Weixiao Wang,
  • Jingxin Li,
  • Hongbing Shen,
  • Fengcai Zhu

DOI
https://doi.org/10.1080/22221751.2024.2332660
Journal volume & issue
Vol. 13, no. 1

Abstract

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ABSTRACTEffectiveness of heterologous booster regimes with ad5 vectored COVID-19 vaccine in a large, diverse population during the national-scale outbreak of SARS-CoV-2 omicron predominance in China has not been reported, yet. We conducted a large-scale cohort-control study in six provinces in China, and did a retrospective survey on the COVID-19 attack risk during this outbreak. Participant aged ≥18 years in five previous trials who were primed with 1 to 3 doses of ICV received heterologous booster with either intramuscular or orally inhaled ad5 vectored COVID-19 vaccine were included in the heterologous-trial cohort. We performed propensity score-matching at a ratio of 1:4 to match participants in the heterologous-trial cohort individually with the community individuals who received three-dose of ICV as a control (ICV-community cohort). From February 4 to April 10, 2023, 41504 (74.5%) of 55710 individuals completed the survey. The median time since the most recent vaccination to the onset of the symptoms of COVID-19 was 303.0 days (IQR 293.0-322.0). The attack rate of COVID-19 in the heterologous-trial cohort was 55.8%, while that in the ICV-community cohort was 64.6%, resulting in a relative effectiveness of 13.7% (95% CI 11.9 to 15.3). In addition, a higher relative effectiveness against COVID-19 associated outpatient visits, and admission to hospital was demonstrated, which was 25.1% (95% CI 18.9 to 30.9), and 48.9% (95% CI 27.0 to 64.2), respectively. The heterologous booster with ad5 vectored COVID-19 vaccine still offered some additional protection in preventing COVID-19 breakthrough infection versus homologous three-dose regimen with ICV, 10 months after vaccination.

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