The Brazilian town of Serrana is applying the CoronaVac vaccine developed by China's Sinovac Biotech to achieve herd immunity.

According to its mayor Leo Capitelli, the vaccine is so far very safe.

Serrana was hit particularly hard by the first wave of infections in Brazil last year.

It implemented a vaccination campaign called "Project S" between Feb. 17 and April 1, aiming at vaccinating all 27,772 adults in the town.

At least 97.7 percent of them have been vaccinated.

Produced by Xinhua Global Service