At the end of November, the National Health Surveillance Agency (Anvisa) approved Pfizer’s bivalent vaccine against Covid19. Health Minister Marcelo Queiroga announced that the first batches of the immunizing agent should arrive in the first weeks of December, but without specifying the date or the amount of inputs made available, raising doubts among the population.
Since the beginning of the pandemic, the virus has been mutating — which is normal — but because of this, updated vaccines need to be made. The new Immunizers are manufactured by the pharmaceutical company Pfizer and protect against the original strain of the virus, the Omicron variant and its subvariants BA.1, BA.4 and BA.5.
These vaccines stimulate our immune system to develop a more specific and therefore more effective line of defense against the virus. Their goal is to expand the immune response and improve civil protection.
It is likely that the incoming broadcast will not include the entire population, making it necessary to form a new contingency of groups. According to experts consulted by EXTRA, priority groups, i.e. those at higher risk of contracting the severe form of the disease, will be the first to receive the bivalent vaccine. These are: immunocompromised people whether transplanted, with autoimmune diseases or cancer patients and the elderly over 75 years of age.
In clinical studies, the bivalent vaccine demonstrated the ability to produce four times more neutralizing antibodies against the BA.4 and BA.5 variants compared to the monovalent vaccine, particularly in these risk groups.
— It is important to emphasize that the current vaccines, i.e. the monovalent ones, also had a similar result and continue to offer protection. So much so that we were going through a new wave of Covid cases and the number of hospitalizations and deaths didn’t have as much of an impact as previous waves. But the vaccine is preventive, we need it to always be anticipatory, updated and best prepared to protect ourselves from what we may face in the future says infectologist and Fiocruz researcher José Cerbino.
Don’t wait for new immunizers
José Cerbino also explains that people should not wait for the arrival of the new vaccine to proceed with the doses envisaged in the calendar and to complete the program with the vaccines already available. Especially the population with comorbidities or risk groups who have already taken their dose a few months ago and need an always high immune response.
— There are still many doubts about the vaccine distribution as we know that the new immunizers are good and effective for the general population, but the current vaccines are also playing their role and protecting people from more severe cases, hospitalizations and deaths. So it is necessary for the other groups or only for the priority ones says the vicepresident of the Brazilian Society of Infectious Diseases (SBI), Alexandre Naime.
The infectious disease specialist says the bivalent vaccine will “apparently” be split into two doses for priority groups at intervals of up to six months and just one dose for the general population. It can be used as a single booster dose for those who have received the first dose of the monovalent vaccine, regardless of the manufacturer.
More than 77 million missed their first booster shot
Unlike during the use of the primary schedule with two vaccine doses or a single dose, where the population visited the health centers in large numbers, the third dose did not have the same commitment and suffered a decrease in the number immunized with the vaccine.
“More than 77 million people have failed to visit immunization centers to get their first booster shot. Studies show that the strategy of strengthening the vaccination schedule increases protection against severe cases and deaths from Covid19 by more than five times,” said Health Minister Marcelo Queiroga.
— Many people are confused and think that the vaccines that children (aged 6 months to 3 years) receive today are bivalent vaccines, but they are not. Aside from the fact that it hasn’t arrived in Brazil yet, Anvisa has only approved its use for people over the age of 12. Another question I’m often asked concerns the adverse effects it can have. There are no differences between Pfizer’s bivalent and monovalent vaccines. As with any vaccine, a small group may experience pain at the injection site, body, or head in addition to fever. I emphasize that the clinical research conducted did not reveal any serious side effects in any of the participants. It’s perfectly safe,” says Patrícia Vanderborght, Fiocruz’s PhD in molecular biology and manager of human immunization at the Richet lab in Rede D’Or.
In addition to the European Union, the two vaccines are already approved in around 35 countries, including Canada, Japan, Great Britain, the USA, Australia and Singapore.