Study will last two years; results are still preliminary September 26, 2021 | 07:03
Pfizer boosts 20-fold increase in antibodies in CoronaVac vaccinates
The booster with the Pfizer vaccine increased up to 20 times the level of antibodies in people immunized with the complete CoronaVac regimen, point out preliminary results of a study carried out in Uruguay, where 24% of the population has already received three doses against Covid-19 .
Since early March, scientists from the Pasteur Institute (IP) in Montevideo and the University of the Republic (Udelar) have been carrying out a research project to study the evolution of levels of specific antibodies against the coronavirus in relation to vaccines and administered doses. The study, which involves more than 200 volunteers, will last two years and provides for periodic blood sampling from the participants.
In a first subgroup, 57 people had blood drawn on four occasions: before being vaccinated, 18 days later, 80 days on average after the second dose of CoronaVac, and 18 days on average after the Pfizer booster.
In the first sampling, none of the participants had specific antibodies against the coronavirus, which was to be expected, as none of them had contracted the virus. In the second, 100% had specific antiviral antibodies, at varying levels.
After the third collection, an overall decrease in antibodies was observed in relation to the levels detected in the second sample. Finally, after the booster dose, it was found that all participants had an increase in the level of antibodies on average 20 times greater than that observed in the second collection.
“These are preliminary results, in a particular population”, highlighted this Friday (24) IP researcher Sergio Bianchi, at a press conference. Scientists will continue to monitor to see how long antiviral antibody levels will be maintained after vaccination.
Uruguay has 3.5 million inhabitants, and 72% of the population has already been vaccinated with the complete regimen of CoronaVac, Pfizer or Astrazeneca, while 24% have already received the booster dose.
Folha de São Paulo