Brazil has recorded a 95% reduction in deaths in the first-ever mass Covid-19 trial, during which an entire town in the country was inoculated with China-based Sinovac Biotech’s CoronaVac vaccine.
Named Project S, the trial ran between February and April, vaccinating all adults in the Serrana town, which has a total population of 45,000 people.
Approximately 75% of residents were completely vaccinated and of the target adult population, 95% turned up for both doses, Bloomberg noted.
About one-third of the town’s population was ineligible for the vaccine due to being under 18 years old or pregnant.
Data showed that the Covid-19 vaccine lowered deaths by 95% in the initial five weeks following the mass vaccination while symptomatic cases reduced by 80% and hospitalisations dropped by 86%.
Brazilian public-research centre The Butantan Institute, which organised the trial, said that Covid-19 cases and deaths decreased in Serrana even when neighbouring regions saw a rise in infections caused by the SAR-CoV-2 P1 variant first identified in the country.
The vaccine did not cause any severe side effects and no Covid-related deaths were reported among participants 14 days following the second CoronaVac dose.
This data from Project S is considered a milestone in understanding the use of mass vaccination to fight the ongoing Covid-19 pandemic.
The Butantan Institute research director Ricardo Palacios was quoted by Bloomberg as saying: “Now we can say that it’s possible to control the pandemic with vaccines. This shows that it isn’t necessary to vaccinate children to open schools.”
According to the news agency, more than 600 million CoronaVac doses have already been distributed across various countries, including China, Hong Kong and Peru.
Though the vaccine cleared the minimum efficacy threshold of 50% in clinical trials, findings from countries that widely inoculated with the shot were reported to be ‘broadly positive’.
Preliminary trial results announced in March this year revealed that CoronaVac demonstrated favourable safety and induced immune responses among children and adolescents.