An entire Brazilian city will be vaccinated against COVID-19 in a giant experiment. The goal is to test if vaccines reduce the spread of the virus.
The city of Serrana in the state of São Paulo is home to some 30,000 adults, all of whom will be offered the COVID-19 vaccine over the next three months as part of a study by the Butantan Institute in Brazil.
All residents of the city over 18 years old (except for pregnant women, lactating women and those who suffer from serious illnesses) will be offered the CoronaVac vaccine, developed by the Chinese company Sinovac, CNN reports. The aim of the study, known as Project S, is to see if a vaccine will reduce the spread of the virus.
Although clinical trials have clearly shown that Sinovac vaccines and other COVID-19 vaccines reduce the likelihood of developing symptomatic illness, data on whether vaccines can completely prevent infections (even asymptomatic ones) remains limited. Some of the earliest hints suggest that at least some vaccines can prevent infections; A few weeks ago, the University of Oxford released data showing the Oxford AstraZeneca vaccine could slow the spread of the virus.
Of course, each vaccine is likely to differ in its ability to prevent infection, as each has different effectiveness in preventing mild or severe illness.