@Firefliess
That's an interesting article *@Em77*. Thanks. But where did you get the data from that that area's currently seeking a second wave? The area with the high antibody rates is only a small part of Brazil, so data from Brazil as a whole (a huge county) isn't really relevant.
Apologies, it was this NPR article:
“In Brazil's jungle metropolis of Manaus, nurse Francinete Simões thought she had seen the last COVID-19 death at the urgent care center where she works in July. Hospitals finally had space to take critical patients again after a violent initial wave of the virus left many of the city's dead in mass graves.
But in recent weeks, Simões says, hospitals are "filling up, and I'm seeing people die again." The state government has now ordered non-essential businesses to close between December 26 and January 10 as a virus containment measure for this city of 2.2 million.”
www.npr.org/sections/goatsandsoda/2020/12/24/949799132/the-worst-of-covid-should-be-over-for-one-hard-hit-brazilian-city-but-its-not
The interesting point I took from the Science mag article was the conclusion about herd immunity:
In conclusion, our data show that >70% of the population has been infected in Manaus approximately seven months after the virus first arrived in the city. This is above the theoretical herd immunity threshold. However, prior infection may not confer long-lasting immunity (30, 31). Indeed, we observed rapid antibody waning in Manaus, consistent with other reports that have shown signal waning on the Abbott IgG assay (14, 32). However, other commercial assays, with different designs or targeting different antigens, have more stable signal (14), and there is evidence for a robust neutralizing antibody response several months out from infection (33). Rare reports of reinfection have been confirmed (34), but the frequency of its occurrence remains an open question (35). Manaus represents a “sentinel” population, giving us a data-based indication of what may happen if SARS-CoV-2 is allowed to spread largely unmitigated.