New Omicron Subvariant Can Escape More Antibodies; know how to protect yourself

The arrival of the omicron subvariant BQ.1 in Brazil raises concern among specialists due to its ability to evade antibodies and increases the importance of booster doses.

The new strain is responsible for the recent increase in cases in the United States and Europe and has already been identified in Amazonas, Rio de Janeiro and Rio Grande do Sul.

“She manages to evade the antibodies, both produced by those who were vaccinated and by the natural infection, which increases her ability to cause infection”, says Alberto Chebabo, president of SBI (Brazilian Society of Infectious Diseases).

Infectologist Francisco Ivanildo Oliveira Junior, medical manager at Hospital Infantil Sabará, explains that the subvariant presents a modification in the format of the protein recognized by the antibodies, making it difficult to fit and, consequently, its effectiveness in combating the invader.

“Imagine copies of keys. If the locksmith doesn’t make a key exactly the same, sometimes the copy can even open the lock, but it opens with a little more difficulty and, depending on the change, it doesn’t even enter the lock. characterizing the mutations, they are small changes in this fitting mechanism”, he comments.

After weeks without a record of Covid-19, Sabará recently treated 14 children with the disease, eight of them between October 26 and November 1.

In the case of BQ.1, as the antibodies work harder to bind to the virus, it is necessary to have more of them for an effective fight. “The vaccine stimulates the production of antibodies, but after some time this production starts to fall and, as this antibody does not have such a good affinity with the virus, I need a larger amount to compensate for the deficiency in the connections”, says Oliveira Junior .

And the best way to keep the number of antibodies high, doctors point out, is to follow the complete vaccination against Covid-19, including all the recommended booster doses.

“The two-dose regimen is not enough to completely protect against these new subvariants precisely because of this immune escape, because of the mutations they have”, reinforces Chebabo.

In a statement published at the end of October, the WHO (World Health Organization) advisory group on the evolution of the Sars-CoV-2 virus gathered information on two new subvariants of the omicron: XBB and BQ.1. For experts, they do not diverge enough to gain a new label or change the way Covid-19 is being tackled, but the situation will be regularly reassessed.

According to the WHO, XBB and its derivatives are a recombination of the omicron sublines BA.2.10.1 and BA.2.75. In early October, they had a global prevalence of 1.3% and had already been detected in 35 countries, including Singapore and India.

BQ.1 and its subline BQ.1.1, in turn, come from BA.5 and, a month ago, had a prevalence of 6% and were registered in 65 countries. In the document, the WHO draws attention to the mutations of these subvariants and the immune escape, but indicates that there are no data that suggest an increase in the severity of the disease.

For Chebabo and Oliveira Junior, the biggest concern at the moment in Brazil is with children. Cities such as Rio de Janeiro have suspended vaccination with Coronavac in children aged 3 and 4 years due to lack of doses and survey of the Sheet released on Monday (7) shows that only 13.9% of boys and girls in this age group started the vaccination course.

For those who have six months to three years, Anvisa (National Health Surveillance Agency) released the vaccination with the immunizer from Pfizer and, although the first batch has already arrived in the country, vaccination has not been started.

“It is important that the Ministry of Health quickly make these vaccines available to the entire pediatric population, because today, together with immunocompromised patients, it is the one with the greatest risk”, defends Chebabo.

“We are incurring a tremendous failure because we are failing to protect a considerable contingent, which has the chance of becoming infected and of evolving with severity”, emphasizes Oliveira Junior, remembering that the disease can lead to SIM-P (Pediatric Multisystem Inflammatory Syndrome), to the long Covid and even the death of children.

Questions and answers

Was the arrival of the subvariant BQ.1 to Brazil expected? Yup. With the increase in cases in the United States and Europe and the ease of transportation, the arrival of BQ.1 in Brazil was imminent.

What are the symptoms of the subvariant? Like other omicron subvariants, BQ.1 can cause fever, runny nose, gastrointestinal symptoms, body pain, headache, sore throat, and hoarseness.

How to protect yourself? Taking all the doses of vaccine recommended for your age group, including booster doses, is the best form of protection. In addition, it is important to intensify hand hygiene and, in the case of the elderly and immunocompromised people, wear a mask in closed or crowded places.

How to protect children who do not yet have a vaccine available? Avoid taking them to closed or crowded environments, such as supermarkets, malls and restaurants, and if possible, also flee public transport.

Visits from family and friends with respiratory symptoms should be postponed and it is worth reinforcing the importance of hand hygiene before contact with the child. If she goes to the day care, learn about the operation of the unit, check if there are adequate points for hand hygiene and if the professionals are oriented.