Study registration: *
Publication Li N-X, Emerg Microbes Infec, 2021
Dates: 2021-05-18 to 2021-06-20
Funding: Mixed (The Key Project of Medicine Discipline of Guangzhou; The Basic Research Project of Key Laboratory of Guangzhou; Foshan Scientific and Technological Key Project for COVID-19; Zhuhai Scientific and Technological Key Project for COVID-19; COVID-19 Vaccines Scientific Research Project of the China National Key R&D Program; The Health Science and technology Project of Guangzhou)
Conflict of interest: no COI (The authors declare that they have no conflicts of interest.)

Methods

Study design:Test-negative
Description of participants: Adults aged 18-59 years undergoing PCR testing in China.
Inclusion criteria:
  • We have only included the population aged 18-59 years given their priority to be vaccinated according to the national policy as of June 2021
  • Cases and controls were selected among the COVID-19 patients and close contacts of cases who had a high probability of contracting the virus
  • residing in Guangzhou

Exclusion criteria:
  • NR

Follow-up duration (months): 1.1
Vaccines:
  • 1 or 2 doses of HB02 or WIV04 or CoronaVac
Variant description :
Variant name: Delta
Evidence: Indirect evidence (prevalence of variant in the population: 80)
Documents
available

Protocol

NR

Statistical plan

NR

Data-sharing stated: NR
Data accessibility: NR
General comment Concerns about uncontrolled confounding; factors such as socio-economic status and ethnicity were not adjusted for.