SERRANA, Brazil—This town of 45,000 people in southeastern Brazil has been at the center of a unique experiment for the past three months: vaccinate nearly every adult against Covid-19 and see what happens.
In recent weeks, after most of the adults here got their second dose, Covid-19 cases and deaths plunged and life has started to return to normal as the pandemic continues to rage across Brazil.
In the heart of Serrana, children squealed with laughter as they chased each other across the main square, while groups of friends—many unmasked —stopped to chat and bask in the afternoon sun.
“We feel free,” said Homero Cavalheri, 68 years old, a retired architect who said he no longer spends his afternoons cooped up at home. He was strolling with his wife, Irene, and their 1-year-old grandson. “Everything is new to him,” said Mr. Cavalheri, clutching the boy. “He keeps pointing at all the trees and the birds.”
The experiment in Serrana, a town in Brazil’s sugar-cane-producing savanna, provides hope for countries around the world still battling with coronavirus outbreaks that mass vaccination works. It also offers new evidence of the efficacy of Sinovac’s Covid-19 vaccine, which is being rolled out in dozens of developing nations from Egypt to the Philippines.