Rio de Janeiro and Fiocruz are going to vaccinate all adults on the island of Paquetá, which is an hour’s ferry ride from the city center, in a new study on the safety and effectiveness of immunization agents against Covid-19, as is already happening in the municipalities of Serrana and Botucatu (SP).
The objective is to evaluate how mass vaccination acts to protect those who have not been immunized, such as children and adolescents, in addition to observing whether the first dose will be able to prevent transmission of the virus in the region or whether this will only effectively happen after the second dose.
According to the city hall, Paquetá has a population of 4,180 people, of which 3,530 are over 18 years old registered in the family health system. Among them, 52% took the first dose and 30% the second dose by the end of May.
The idea is that the rest of the eligible residents receive the first dose of the immunizing agent from AstraZeneca/Oxford on the next 20th, a Sunday. The participation of tourists who are spending the weekend on the island will be prohibited.
Residents must first undergo a serological blood test, which will be repeated throughout the survey. With full coverage of the target population, epidemiological monitoring will be carried out for a period yet to be established. The project was named “PaqueTá Vacinada”.
In the study of the municipality of Serrana, carried out by the Butantan Institute using Coronavac, preliminary results found at the end of May that the city had a 95% reduction in deaths from Covid-19 eight weeks after the start of mass application, with 95% of the immunized adult population.
The so-called S project vaccinated 27,160 people, divided into four groups. Each of them received the bite within a week of each other. After the last group obtained the first dose, the application of the second dose in the first group started.
As a result, the researchers were able to observe a significant drop in the number of new symptomatic Covid cases and hospitalizations when 75% of the eligible population was fully vaccinated, that is, when the third group of four received the two doses of Coronavac.
“A remainder of cases [sintomáticos] and deaths was significant even before we had completed the application of the second dose in the last group, which shows us the effect of indirect immunity,” said Ricardo Palacios, medical director of clinical research at Butantan at the time. Monitoring should continue for up to one year, quarterly.
In Botucatu, the study began in mid-May and is being carried out through a partnership between the Ministry of Health, Unesp (local campus of the São Paulo State University), city hall, Oxford University and the Bill and Melinda Gates Foundation.
In addition to verifying the effectiveness of the vaccine, the project intends to assess its effectiveness against the new variants in circulation. According to the research coordinators, all detected samples of the virus will undergo analysis with genetic sequencing.
It is estimated that around 80 thousand people, between 18 and 60 years old, receive the immunizing agent from AstraZeneca and are evaluated for a period of eight months. Elderly people were not included, as they are already being assisted by the National Immunization Program (PNI), nor pregnant and postpartum women.