The emergence of the Ômicron variant of the coronavirus about a year ago took the Covid-19 pandemic to a new level. It was followed by new spikes in cases around the world, with people being reinfected and studies showing the effectiveness of vaccines in preventing infections falling.
The large number of mutations found on the surface of the virus made it so different from the original found in Wuhan in December 2020 that some scientists, such as the infectious disease physician and head professor at the Department of Infectious and Parasitic Diseases at the USP School of Medicine, Esper Kallás , discuss the possibility of classifying it as Sars-CoV-3.
In a lecture at the 24th National Immunization Journey SBIm 2022, which takes place between 9/7 and 9/11 in São Paulo, Kallás defended the idea of the Covid-19 pandemic being divided into two moments: pre and post emergence of the Ômicron variant. .
“Until December 2021, reinfection by different variants was a virtually rare event. Vaccines came and were extraordinary in preventing deaths. After the identification of Ômicron, a second pandemic began and the other variants practically disappeared. The way it happened was overwhelming.”
Studies show that the virus currently circulating has accumulated a large number of mutations throughout its evolution, mainly in the region called the viral spike. The area is used by the pathogen to attach itself to human cells, invade them and multiply.
The modification made the virus more transmissible and able to evade the defense induced by previous infections by the original virus and other variants, as well as by vaccines based on them. The subvariants that appeared next – BA.2, BA.3, BA.4 and BA.5 – were successively replacing the previous ones.
“It is a practically different virus from the one found in Wuhan and from the Alpha, Beta, Gamma and Delta variants. Many researchers debate the idea of classifying it, perhaps, as Sars-CoV-3. Ômicron would be a different enough variant to deserve this consideration,” said Kállas.
With the emergence of new variants, much has been discussed about the need to develop a new generation of vaccines and what would be the best approach to them. Pharmaceuticals Moderna and Pfizer/BioNTech took the lead in this race. They were the first to launch immunizers with a bivalent formula – made up of a mixture of the original strain and the subvariant BA.1 of Ômicron –, with authorization for use by the main international regulatory agencies, such as the United Kingdom, United States and the European Union.
Pfizer sent the National Health Surveillance Agency (Anvisa), on August 19, a new application for authorization for emergency use of the updated vaccine. The data is still under analysis. Results of new Moderna and Pfizer/BioNTech studies on reformulated boosters to combat the currently dominant subvariants BA.4 and BA.5 have already been submitted for review by the European Medicines Agency (EMA).
“I think this is the way: we will have to adapt vaccines. Adding a new Ômicron variant within the composition is appropriate. It is the recommendation of the FDA (US regulatory agency). In conversations with Anvisa, we have already noticed this same type of design and suggestion for Brazil”, said the professor.
The doctor highlighted that, while the updated vaccines do not arrive, the population must continue to be immunized with the available options to ensure protection against serious forms of infection and, consequently, reduce the risk of death.
“The vaccines we have so far still demonstrate a protective capacity against serious disease. We cannot dispense with them”, emphasized Kallás.
*Reporter Bethânia Nunes is in São Paulo, invited by the Brazilian Society of Immunizations (SBIm), to accompany the XXIV National Immunization Journey SBIm 2022.
Get news from metropolises on your Telegram and stay on top of everything! Just access the channel: https://t.me/metropolesurgente.
#SarsCoV3 #scientists #Omicron #virus