P.1

        The city of Manaus in Brazil lies alongside the Amazon River. Like many of the cities and villages connected by this life source, the COVID pandemic hit the people swiftly and with might. At the peak of the pandemic, people were dying at unprecedented rates and the city was forced to cut down swaths of forest to create more gravesites. While the toll has been large, health experts were hopeful when a drop in incidence corresponding with a greater than two thirds seropositivity rate among people in Manaus appeared. They thought Manaus had reached a point where enough people had been infected that the spread was slowing. 

But soon, cases began to rise again and researchers didn’t know why. Meanwhile, across the world reports of new SARS-CoV-2 variants began popping up. Suspecting the worst, one Brazillian doctor began doing genetic sequencing of the virus that was being isolated from sick patients in Manaus and found that there were mutations of the receptor binding domain of the spike protein in this strain of SARS-CoV-2. 

Mutations in the receptor binding domain of the spike protein are the most dangerous. Antibodies that protect us during the course of an infection do so in part by preventing the virus from being able to bind to and enter its target cells. Antibodies that bind to and directly block the receptor binding domain of the virus are the best at offering protection from infection. Mutations in this region by the virus may allow them to escape recognition by both vaccine-induced and naturally produced antibodies. 

When the researchers back traced the rise of this variant in Manaus, they found that while it had initially only caused about 20% of the COVID cases, it gradually rose to become the dominant form of the virus active right now. What’s worse, researchers suspect that 60-70% of those who currently have COVID in Manaus have actually been re-infected by the new variant. Their studies found that convalescent serum of previously naturally infected people was six-fold less potent at neutralizing the new variant, named P.1. 

As P.1 has begun to spread to other places in the world, people are rightly becoming concerned. As public health officials are saying, it is important that we continue to use all the means we have to fight back against the virus’ spread including social distancing and mask wearing. Settling into a new normal of life with the pandemic still requires a degree of vigilance.

- Renata

References

NYT: Virus Variant in Brazil Infected Many Who Had Already Recovered from COVID-19, March 2021, accessed March 1, 2021

NYT: The Amazon, Giver of Life, Unleashes the Pandemic, July 25 2020, accessed March 1, 2021

Souza et al., Levels of SARS-CoV-2 lineage P.1 neutralization by antibodies elicited after natural infection and vaccination, The Lancet (Preprint), March 2021