BQ.1: what is known about the omicron variant discovered in Brazil

A new variant of the coronavirus, called BQ.1, has been identified in Rio de Janeiro, according to the Municipal Health Department.

The variant had already been found in Amazonas on October 20, according to the Fiocruz unit in the state, which strengthens the assumption that it circulates in different parts of the country.

In an interview with BBC News Brasil, the Municipal Secretary of Health of Rio de Janeiro, Daniel Soranz, explained that the patient diagnosed in the city is a 35-year-old woman, resident of the north and without serious symptoms.

“She already had four doses of the vaccine, so the symptoms are mild and similar to infections with other variants. The patient had not traveled, which means that this variant is already causing transmissions locally”, completes the secretary.

According to data from the Ministry of Health, interpreted by infectious disease specialist Andre Lazzeri Cortez, among the capitals, the city of Rio de Janeiro had the highest number of cases in the last epidemiological week: 2202 people were infected. Next, Recife has 1,333, Goiânia 611, Manaus 506 and São Paulo 479.

The characteristics of BQ.1

According to infectious disease specialist Alberto Chebabo, president of the Brazilian Society of Infectious Diseases, BQ.1 is derived from the ômicron variant.

“It’s the same strain that circulates in Europe today and has caused an increase in infections in countries like Germany and France.”

There are no changes in terms of symptoms, which continue to be, for most patients, headache, cough, fever, sore throat, tiredness, loss of smell and taste.

The main feature that differentiates it from other strains, explains the doctor, is a much greater escape from vaccine protection.

BQ.1 has mutations in the spike protein, a protein on the surface of Sars-CoV-2 that allows it to bind and infect our cells.

Among them is the R346T mutation, also found in the BA.5 variant, which is associated by studies with significant immune escape and even antibody evasion caused by natural infections by other subvariants of the omicron.

“But what we see happening in Europe is that as long as people have the booster shot, it overcomes their immunity to the infection, but it doesn’t cause serious cases.”

In Rio de Janeiro, according to Soranz, of the 47 patients hospitalized in the city, 92% did not take the booster dose or any other dose of the vaccine.

Increase in cases is expected

The variant was identified in Rio de Janeiro by Fiocruz. “We have a sentinel unit that selects samples of positive cases in the city and sends them for genetic sequencing. We have been doing this regularly since 2021”, says the municipal health secretary.

Soranz points out that the subvariant may be related to the increase in the number of cases seen in recent weeks.

Infectologist Alberto Chebabo indicates that the increase in cases should still happen in the next three to four weeks. “It will be the result of the circulation of the new variant associated with other issues, such as end-of-the-year get-togethers and even factors in the life that followed normally, with many people not wearing a mask in workplaces, for example.”

Recommendations for the population

The main recommendation is to have a complete and updated vaccination schedule, including the two booster doses.

“It is worth remembering that infections by Covid-19 also indirectly imply an increase in morbidity from cardiovascular diseases, and sequelae that are sometimes irreversible”, says the infectious disease doctor and professor at Unoeste Guarujá, Andre Lazzeri Cortez.

“The proportion of susceptible individuals in the population directly influences the transmissibility of new subvariants. This proportion can vary because the immunity of individuals, whether induced by previous infection or the response induced by vaccines, decreases in a few months”, he warns.

Doctors consulted by the report also recommend looking for a basic health unit if symptoms commonly associated with Covid-19 appear.

“Extreme care should be taken in the case of pregnant women, the elderly, underweight children, immunosuppressed patients and those with uncontrolled chronic comorbidities”, recommends Cortez.