Recently lost an acquaintance who was hospitalized with Covid. He and his wife were regrettably adverse to the vacinnes, contracted Covid, both were hospitalized, she recovered and he was taken after being placed on a respirator. He was otherwise healthy in his late sixties. Tragic.
The following 3/12/22 NY Times article reports Covid as very active in Brazil.
https://www.nytimes.com/interactive/2021/world/brazil-covid-cases.html
I don't believe Mr McAffrey mentioned the locations of the trial sites other than Southern Brazil. Southern Brazil still has a Covid pandemic.
Chicagoest