Sichuan Clover Biopharmaceuticals Inc. of China says it is conducting a second-phase clinical trial in Brazil of its vaccine against COVID-19.

Sichuan Clover told the Hong Kong Stock Exchange last week that it would test the vaccine on 520 healthy adults in various places in Brazil, and that it expected the safety and immunogenicity results in the first half of next year.

The company says it means to assess the vaccine as a booster for people inoculated with CoronaVac, a vaccine devised by Sinovac Biotech Ltd. of China, or with Covishield, a vaccine marketed by AstraZeneca plc of Britain and Sweden.

The Brazilian Instituto D’Or de Pesquisa e Ensino, which does healthcare research, is sponsoring the trial, the Brazilian Ministry of Health is supporting it, and the Bill and Melinda Gates Foundation is funding it, Sichuan Clover says.