Reinforcement against Covid is important to prevent hospitalization, says Julio Croda

Updating Covid vaccines to bivalent formulas that include omicron subvariants is important, but what is essential now is the application of a more recent dose, even with the traditional formula, in the older population. This is the view of infectologist and Fiocruz researcher Julio Croda.

In addition, for him, older people or those at greater risk, such as those who are immunosuppressed or undergoing cancer treatments, should already receive a fifth dose of immunizers before the arrival of bivalent vaccines.

According to Croda, waiting for the arrival of Pfizer’s bivalent vaccine against omicron to update the immunization of older people can delay the process of recovery of protection levels.

“We are already experiencing an increase in cases, hospitalizations and deaths in Brazil, especially in the group we call ‘extreme elderly’, over 70, 80 years old. Waiting until the arrival of the bivalent can put these people at risk and waste time necessary to generate this additional protection at a time of high transmission of the virus”, he says.

As vaccines need 7 to 10 days to start stimulating the immune system to generate protection against the virus, a now application of older vaccine formulas may result in greater immunization against circulating omicron subvariants, even if the efficacy is not as high as that observed in previous moments of the pandemic.

At the end of November, Anvisa (National Health Surveillance Agency) approved two new bivalent Covid vaccines, produced by pharmaceutical company Pfizer. The formulas have the ancestral strain of the Wuhan coronavirus and the omicron subvariants BA.4/BA.5 and BA.1. The first doses should arrive in Brazil in December this year or in January 2023, according to Croda.

According to him, the Ministry of Health has not yet defined how the bivalent will be applied, although there is discussion that it is intended only for risk groups. “I think it was a wise decision, as was done in Europe, because in the United States they released it to the general population over five years and adherence is low”, he explains.

The infectologist recalls that a campaign to boost the vaccine against Covid also needs to work with communication and the importance of people receiving the last dose of the vaccine less time ago, and not necessarily what that dose is.

“From the population point of view, the ideal is that everyone had an up-to-date vaccination schedule, with greater coverage of this schedule, and only then can we replace the bivalent formulation for vulnerable groups”, he says.

The government transition team of the president-elect, Luiz Inácio Lula da Silva (PT), has already signaled that vaccination will be one of the major campaigns in the health area to be resolved as early as next year.

In addition to the updated Covid vaccine, the next administration intends to recover coverage of other vaccines in the children’s immunization schedule, which have had a significant drop in the last five years.

Last Sunday (4), Vice President Geraldo Alckmin said that vaccinating children against Covid will also be one of the first actions of the new government, to start as of January 2.

Recently, capitals reported a lack of immunizations for children aged 3 and 4 years. Those from 6 months to 3 years of age have not yet been widely included in the vaccination campaign, being restricted to children with comorbidities.

The current government’s difficulties in vaccinating children and the delay in purchasing vaccines are some of the criticisms of health experts, including Croda. “After the elderly, we know that children aged 6 months to 5 years are those with the highest risk of hospitalization and death from Covid”, says the infectologist. “We need a concomitant campaign with reinforcement in the elderly”, he adds.