Why I am less nervous: these same concerning anecdotes were present during the Beta surge (Beta South African B.1.351). South African sources echoed quite loudly on the subject:
- There was much talk of reinfection cases.
- There was in vitro reduced neutralizing activity studies that had people up in arms.
- There was great concern of vaccine escape.
So what actually happened since the world didn't end?
- No epidemiologically meaningful reinfection data was ever shown.
- The in vitro experiments didn't transfer over to in vivo and epidemiologically significant effects for pandemic control.
- The vaccine concerns ended up being that the AZ vaccine used in SA was subpar in VEI realworld performance, but still protected extremely well against severe disease.
Beta was not the "Omega strain" feared, nor was its equally supposedly-fearsome cousin Gamma (P.1 Brazil) a terror outside of its emergent region which had the same fears, anecdotes, and in vitro data as Beta. Lambda and Mu were going to do us in as well. Alpha (UK B.1.17), the less fearsome though still more virulent and contagious than Wild Type, ended up being the worldwide dominant strain until Delta (India B.1.617) decisively outcompeted every other strain across the globe.
Will New "Nu" (Botswana/South Africa B.1.1.529) be the immunity escaping Omega strain?
Why I am nervous: concerning anecdotes from SA about immune escape and presumed high seroprevalence in the region, maybe 40% maybe 70% while vaccine uptake is just over 20%. South Africa had it bad, about as bad as anywhere and the situations in their hospitals were just gut wrenching for patients and staff. The issue is of course that there are localized bursts in incidence that follow a mutation of better reproductive fitness which could be similar to Alpha and Delta, but not necessarily immune escape, or it could mean some level of immune escape. We have alterations in areas of the spike protein that could compromise previous infection immunity, vaccine response, and even multicompartment immunity... but will eyeballing a protein/sequence and computer simulation equal reduced activity in vitro? In vivo? Meaningfully so? For those previously infected? For those vaccinated? How about for those boosted? We won't know for 2-4 weeks.
When 1918 H1N1 Paninfluenza went around the world in several waves over the 2+ years of that pandemic, it mutated into more strains than SARS-CoV-2. There was no vaccine, or even real understanding that it was a virus. People were reinfected because the new strains were mutated to the point of immune escape because that is what Influenza virus does best, much better than COVID. But the immune memory was not truly blind. The people who were infected previously had a much milder course and the second time around, and that wasn't simply regression to mean virulence through mutation.
What is clear is that like Delta, "Nu" emerged in a low vaccination region. Mutations come from replications. The only way to cut replications is to prevent infections. The only way to prevent infections long term is vaccinations. Luckily, with mRNA technology, Moderna and Biontech could start the production of a tuned up booster shot next week. If we treat approval as we do seasonal influenza shots, deployment could be faster than the virus moving forward.
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