The Delta variant already represents 63% of Covid-19 cases in Brazil. The data comes from the Corona-omics Network, formed by researchers from all over the country and linked to the Ministry of Science, Technology and Innovation (MCTI), calculated from samples of the new coronavirus deposited on the international platform Gisaid in the last 15 days.
According to the researchers, the lineage originating in India has already reached 24 states and the Federal District.
In Brazil, the Delta strain has not yet been diagnosed in Acre and Roraima, where there are cases under investigation. Almost all of the remaining 37% are samples of the Gamma (P1) variant, from Manaus.
There are also records of Mu and Lambda strains, variants of interest to the World Health Organization (WHO), and not of concern, like the others. However, their presence is residual.
Corona-omics network coordinator and professor at Feevale University (RS), virologist Fernando Spilki understands that Delta repeats in Brazil a pattern observed abroad, and that the previous outbreak of the Gamma variant may have delayed the spread of the lineage originating in India.
“Probably the short-lived immunity we got from the massive Gamma outbreak delayed Delta’s spread, but its path is well established in several states, displacing other variants. Mainly, dislodging Gamma and occupying protagonism. Fortunately, we still don’t have an increase in the number of cases, except in Rio de Janeiro. But that could still happen in the coming weeks”, he assesses.
Another reason pointed out by the researcher for Delta’s slower progress is the high level of antibody production caused by recent vaccination against Covid-19.
To analyze the situation by state in proportional terms, the network has used the cut of the last 45 days, to ensure that all units of the federation are represented in this period, because some did not deposit samples in Gisaid at shorter intervals.
Under these conditions, based on sequencing carried out in the period, Rio de Janeiro has more cases of the Delta variant: 85%, followed by São Paulo, with 77%, Paraíba 76%, Santa Catarina 70% and Minas Gerais 42%.
The virologist emphasizes that the scenario calls for attention, because it is not simple to predict the behavior of the virus from the moment it becomes prevalent in each area.
“We even saw an increase in the number of cases in Rio after it surpassed the 50% barrier. For now, it is effectively difficult and will vary with the epidemiological situation in each location. We cannot set, as we imagined, a limit. What we need to be very attentive to is the count of cases from now on, because it (Delta) dominates the scene in several places”, concludes Spilki.