Science
Related: About this forumOne of The First Covid Hotspots Outside of Asia Shows Promising Long-Term Immunity
Along with mass testing campaigns in February and March of 2020, scientists tested the majority of Vo's population for SARS-CoV-2 antibodies again in May 2020. They found that around 3.5 percent of the population (around 100 people) had been infected at some point in the past.
In November 2020 they followed up again, and they asked all those who had tested positive to either the antibody or swab test to get another antibody test to see who still had antibodies to the virus.
The team found that 98.8 percent of the people who had tested positive in May 2020 still reacted to at least one type of antigen in November, meaning that antibodies were sticking around for at least six months more likely closer to nine from when they were first infected.
https://www.sciencealert.com/study-of-italian-village-suggests-antibodies-probably-persist-at-least-9-months-after-infection
Great news for those of us who survived the bugger and most likely applies to the vaccines, also.
Pobeka
(4,999 posts)That area in Brazil had about 76% (!) of the population infected in the first wave. Didn't prevent them from being reinfected in a second wave for the most part.
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I do think I recall a study showing that the mRNA vaccines showed good levels of antibodies 6 (or 9?) months after the injection.
Warpy
(111,255 posts)Were these second cases severe, mild, or detectable only via PCR?
Vaccinated people are getting breakthrough symptoms from Delta. They're just not dying from it and most aren't ill enough to go to the hospital.
With no immunity to the virus, an infected person will take about 2 weeks to mount an effective immune response, enough time to kill some people who are infected. With immunity, that is cut down to days. We're seeing breakthrough mild infections because the Delta variant tends to hit people so quickly. The rapid immune response just means it won't hit them very hard unless there are massive underlying health conditions and/or a poor immune response.
Pobeka
(4,999 posts)The paper doesn't go into the details of the severity, but as I recall from news reports about it the second wave was just as bad as the first in terms of hospitals being overrun. It was clearly the poster child for natural immunity not being effective against a new variant.
Warpy
(111,255 posts)to the extent that the immune response takes days rather than two weeks to mount an effective response, meaning fewer people will be hospitalized or dead from the Delta variant, no matter how they developed immunity to it.
That' is why incomplete reporting like this is so infuriating. It gives ammunition to the "vaccines don't work, so why bother?" crowd, and that is the last thing we need.
I expect better of The Lancet, even if they did get conned by Wakefield years ago.