Expert estimates imminent arrival of new Covid-19 strain
The BA.4 and BA.5 subvariants of omicron are causing hundreds of thousands of infections in Europe and the United States.
Although the BA.4 and BA.5 subvariants of the omicron lineage have not yet been identified in the Dominican Republic, causing the fifth wave in the country, researcher Robert Paulino warns of the importance of the country being forewarned and reinforcing its preventive measures and seeing his arrival imminent.
He warned that the BA.4 and BA.5 subvariants, detected for the first time by scientists in South Africa in January and February of this year, currently represent more than 40% of new infections in the United States, a country with which the Dominican Republic has a constant migratory flow.
He said that the BA.5 subvariant appears to be the worst of all those belonging to the omicron lineage; it can escape the immune response, it is genetically distant from the other subvariants in multiple mutations, and in animal models, it has worse clinical manifestations.
There have been reports about the circulation of the BA.1 and BA.2 subvariants of ómicron detected in the sequencing carried out through the Dr. Defilló National Laboratory.
In statements to Listín Diario, Paulino pointed out that even though no cases of BA.5 have been reported in the Dominican Republic on the GISAID platform (international platform for genomic sequencing of SARS-CoV-2), he understands that its arrival is imminent, as it has been with all other variants of the virus.
He sees that new vaccines will have to emerge that include the new subvariants and that while this is happening, preventive strategies such as social distancing, avoiding crowded and poorly ventilated closed places, and the use of masks continue to be very effective in reducing the risk of infection and reduce the effects of COVID and in the long term of the post-pandemic.
He said recent studies confirm that these new omicron subvariants can be transmitted through the air.
The virologist explained that regarding vaccine schedules, in-vitro studies have shown that two doses do not offer much protection against BA.5.
He adds that after even having a third dose of the Pfizer vaccine, both the BA.4 and BA.5 subvariants escaped vaccine-induced antibodies and infection more effectively than the earlier omicron variants. “This means that reinfections can occur in those people who have recently had the omicron infection. In addition, antibodies from a previous infection with the original BA.1 omicron strain do not protect against BA.4, and BA.5 infection in partially vaccinated or unvaccinated persons.
He says that the therapeutic antibodies used in the stages of COVID show less efficacy against the activity of BA.5, and the L452R and F486V mutations are responsible for this phenomenon. This limits the therapeutic options and the management of cases that could be complicated; little by little, we are observing an increase in hospitalizations.