This appeared to be a virus that would not tolerate change, but time and the persistence of the pandemic have allowed for a new scenario. The new coronavirus was showing modifications and we started to know its new variants. And why does Sars-CoV-2 preserve these mutations?
The main suspicion is that they bring some advantage to the virus, especially in increasing its transmission capacity. But are they associated with the most severe forms of the disease, interfere with the ability of tests, escape treatment and, partially or totally, vaccines?
Coronavirus variations are relatively common, but few retain their ability to transmit. When this happens and a limited group of people becomes infected, it is called a “variant of interest”. If it is transmitted to a large number of people and is responsible for a large portion of those infected in a given region, it is called “concern variant”.
In early June, a panel of experts, brought together by the World Health Organization, brought something new to deal with the new coronavirus: it suggested the adoption of a new nomenclature, in order to facilitate the classification of viral variants.
From now on, the acronyms and numbers come out and the Greek alphabet enters, according to the order in which the discovery took place.
Worry variants entered the queue first. B.1.1.7, isolated in England, was called alpha. In turn, B.1.351, isolated in South Africa, became beta. P.1, which first appeared in Manaus and spread throughout Brazil, is now called gamma. Finally, B.1.617.2, recently identified in India and currently spreading to England and the US, is now known as delta.
Whatever their names, the most worrying thing is that such variants will be able to bypass the immune system’s defenses, as well as treatments and vaccines. So far, there is no evidence that they will be able to beat the available vaccines.
A first important piece of information about the Johnson&Johnson vaccine: evaluation of its efficacy at transmission sites of the beta variant (B.1.351) observed a partial reduction in protection against the appearance of symptoms of Covid-19. On the other hand, excellent protection against more severe forms of the disease, which lead to hospitalization or death, was maintained.
The second came from the S study, carried out in Serrana, in the interior of São Paulo. In it, Coronavac, from Sinovac and the Butantan Institute, proved to be extremely effective. It prevented 86% of hospitalizations and 95% of deaths caused by Covid-19. The predominant variant in the period of analysis was the gamma (P.1). Coronavac, therefore, is effective against the Manaus variant and primarily responsible for the recent broadcast waves in Brazil.
The third piece of evidence concerns the fear that the delta variant (B.1.617.2), recently identified in India, has a greater capacity to evade the defense system. Preliminary results in England, where this variant is spreading, show that the vast majority of cases are occurring in unvaccinated people, with vaccine effectiveness estimated at 95%.
Can variants cause more serious illness? We don’t know all the details yet, which requires tracking the Covid-19’s features where they’re showing up.
Will the treatments that work today work for what lies ahead? In order for us to be prepared for the future, this is a strategic issue that will require maximum attention, also from Brazil.
LINK PRESENT: Did you like this column? Subscriber can release five free hits of any link per day. Just click on the blue F below.