One Brazillian town is making a huge step forward in a time of both a global pandemic and massive global anti-vax movements. With the help of local health research centers and volunteers, the town of Serrana has already vaccinated over 95% of its adult population with the Chinese CoronaVac vaccine. This is not only great news for the townspeople of Serrana but it also offers a fantastic opportunity for researchers and the public worldwide to see just how effective mass immunization can be.
Is it voluntary?
One key issue that pops into most people’s minds when they hear about “mass vaccination” is whether it’s voluntary or not. With millions of people worldwide rejecting vaccination efforts, the news that 95% of the population of a town is getting vaccinated all at once raises some questions.
And the answers are both conclusive and positive – the citizens of Serrana are participating in the vaccination voluntarily. In fact, far-right Brazilian president Jair Bolsonaro has been talking against vaccines in general for months (1) and is especially adamant in his position against CoronaVac. So, any worries about involuntary vaccinations don’t seem particularly reasonable.
How was the whole process organized?
The picturesque town of Serrana is situated in southeast Brazil and consists of only 45,000 people, around 30,000 of which are adults. It’s also very close to an important public health research center, the University of São Paulo’s campus in nearby Ribeirão Preto (2).
The mass vaccination process is done with the help of both São Paulo’s campus, as well as other institutions such as the Federal University of Espírito Santo (3). Together with local authorities and volunteers, researchers have been working for months to persuade the ~30,000 people in Serrana of the benefits of the vaccine and that of mass vaccination in particular (4).
The mass vaccination project has been dubbed Projeto S (5) and its purpose is to help the people of Serrana as well as to measure the real-world effectiveness of the CoronaVac vaccine. The results are especially crucial in relation to the Brazillian P.1 strain of Covid-19 which has been shown to be overly invasive even against people with Covid-19 antibodies (6) (7).
Another goal of the researchers’ study of the vaccination efforts (8) is to gauge just how effective the vaccine is for protecting not just those who had taken the two quick jabs but also the unvaccinated around them. Marcos Borges, project coordinator and director of the Serrana State Hospital (9) describes it as a question of “Whether vaccinated people protect the unvaccinated, how long does their immunity last, and what variants are circulating. We’ll finally be able to observe how a large set of people respond to the vaccine in real-world conditions.”
Projeto S is equally important for everyone else around the world for the same reason. Ethel Maciel, an epidemiologist at the Federal University of Espírito Santo (10) says that
“Projeto S may be the best way to understand the effectiveness of vaccination against COVID-19 in the short and medium terms.”
“This is especially important because we don’t know when we will have most Brazilians vaccinated,” she added.
Brazil is also the perfect place for such research for other reasons. When the project was initiated in February 2021, the researchers from Instituto Butantan, one of the research facilities and a vaccine maker in São Paulo state that’s sponsoring the project (11), set the goal of Projeto S at 80% of the population.
“We took into account that Brazil has a long tradition of good adhesion to vaccination, so we knew these 80 percents were within reach,” said Borges.
That goal was quickly exceeded, however. As of mid-April 27,722 of the ~30,000 adult citizens of Serrana had received the first dose of CoronaVac and the astonishing 27,160 of them had gotten the second jab too. That means that 95.7 of Serrana’s adult population was fully vaccinated just two months after Projeto S was launched.
This is great for the project as well as for the townspeople of Serrana as 80% may have been insufficient for complete herd immunity given that Projeto S used CoronaVac.
How does the Chinese CoronaVac compare to Western vaccines?
The CoronaVac Covid-19 vaccine is developed by the China-based Sinovac Biotech company (12). This vaccine works on a different principle than the popular in the west mRNA Pfizer-BioNTech and Moderna vaccines and even the Oxford-AstraZeneca vector vaccine.
Instead, CoronaVac uses an inactivated or “killed” version of the SARS-CoV-2 virus. This inactivated version is incapable of causing any illness in the vaccinated person but still teaches their immune system to recognize the bio structure of the virus and develop the necessary tools for fighting against it.
While there are benefits to this method, there is also one major drawback – this vaccine has less efficacy than other vector or mRNA vaccines</