RIO DE JANEIRO, BRAZIL – The vaccination campaign against Covid-19 in Brazil began last week, after the emergency use approval by the National Health Regulatory Agency (ANVISA) of two vaccines: CoronaVac, from the Butantan Institute, and the Oxford-AstraZeneca, supplied by Fiocruz.
Immunization is still restricted to a small portion of priority groups, including front-line health professionals, elderly people living in long-term institutions, and indigenous villagers.
The reasons for this are the emergency use authorization itself and the limited vaccine supply. Emergency use authorization is temporary and its administration is limited to certain population groups. However, low supply is linked to production delays caused by problems in the delivery of the active pharmaceutical ingredient (API), which is the basis for the production of the immunizer, as well as a delay in the delivery of doses. The Oxford vaccine, for instance, only reached Brazil on Saturday, about one week late from the initial deadline set by the government.
Despite the mishaps, the start of vaccination of the Brazilian population is a reason for joy and hope for better days. While access to vaccines is not expanded, specialists clarify the main doubts about vaccination in Brazil.
How long after vaccination will I be protected against Covid-19?
Phase 3 clinical trials involving the CoronaVac and the Oxford-AstraZeneca vaccine evaluated the vaccines’ efficacy two weeks after the second dose was administered. Hence, the vaccine takes approximately 15 days to confer protection.
Can I not wear a mask after the vaccine?
No. Experts and the Ministry of Health alert that people who have been vaccinated need to continue taking all preventive care even after vaccination. In addition to wearing masks, this includes maintaining social distancing, constant hand sanitizing and avoiding crowds.
This is essential because the available vaccines are highly effective against severe forms of the disease, but do not fully prevent infection or transmission. “Masks should continue to be worn because the vaccine could fail and also because even if an individual does not develop the disease, he or she could be a carrier of the virus,” explains Renato Kfouri, director of the Brazilian Society of Immunization (SBIM).
Depending on the behavior of the pandemic, these measures may eventually be relaxed or even dismissed, but there is still no estimate of when this will happen.
Can I take the first dose of the CoronaVac and the second of Oxford’s, or vice versa?
No. According to Kfouri, there is still no data concerning interchangeability between vaccines. This means that there are no studies demonstrating that this is either safe or effective. Therefore, to ensure safety and efficacy, administration of two doses from the same producer is recommended.
If I delay the second dose, will I be immunized?
No. The CoronaVac and the Oxford-AstraZeneca vaccines efficacy has been assessed in a two-dose administration scheme within a given period. In the case of the Butantan Institute’s vaccine, efficacy was achieved when the second dose was administered within two to four weeks after the first.
The Fiocruz (Oxford-AstraZeneca) vaccine allows a longer interval: four to 12 weeks between the first and second doses. Therefore, the advice is to observe the time limits to be determined by the government and to strictly observe them. In the event of omission or delay, Kfouri states that the ideal is to seek the healthcare service to take the immunizer as soon as possible.
“One must try to comply with the vaccination scheme. However, even if late, it is better to take the second dose than not at all,” he advises.
Can I choose the vaccine?
No. With the arrival of the first batch of the Oxford-AstraZeneca vaccines in Brazil, two immunizers are available to be administered to the population. However, the Ministry of Health will decide which group or region will be supplied with which vaccine, based on technical and strategic criteria. Therefore, people will not be able to choose which vaccine to take.
“The vaccines will be distributed throughout the country as determined by the National Immunization Plan,” says SBIM’s director.
Can I buy the vaccine in a private clinic?
No. The emergency use authorization granted by ANVISA only allows the public health system to buy and distribute the vaccines. The offer of vaccines against Covid-19 in the private system depends on the official registration of vaccines with ANVISA and the offer of doses by producers. Currently, the available doses have already been negotiated with governments and international consortia.
On Sunday, January 24th, Brazil registered a rolling daily average of 50,925.4 new cases and 1,027.1 deaths from Covid-19 during the past two weeks.