Previously won immune defense bypassed
According to all that is known, P.1 combines several properties of previous mutations: Apparently, like the British variant, it is up to twice as infectious as the wild type of the virus, infected people have a much higher viral load, which makes them potentially more infectious , and P.1 shows 17 changes in the genome. Ten of them concern the spike protein with which the virus docks on human host cells. In terms of genetic changes, it is also similar to the variant from South Africa (B.1.35) – both carry the mutation called E484K.
The situation in the northwestern Brazilian city of Manaus shows what effects these numbers can have on the course of the pandemic: In the metropolis with a population of millions, there has recently been another large increase in corona cases, although many people there had already been infected with the first wave in the spring of last year. According to a study in the journal Science, the rate was 66 percent at the time, which is why epidemiologists at the time even assumed herd immunity.
Conflicting effectiveness data
A study by researchers at Oxford University, which has not yet been peer-reviewed, at least produced positive results. Accordingly, the vaccines from Biontech and AstraZeneca would work better against P.1 than initially assumed. “The results suggest that P.1 is possibly less resistant to vaccine and immune responses than the South African variant.” The agents would have a similar effect to the British variant.
Another study that has not yet been assessed comes to a different conclusion: Compared to P.1, the effectiveness of the Biontech and Moderna agents is significantly lower.
Even if it turns out that the previous vaccines offer at least some protection, the escalating corona situation in Brazil harbors further dangers: Because the number of infections is high, the virus has many opportunities to change again. Experts fear that a kind of supervirus will develop against which none of the known vaccines could actually help.