Thread by @DrEricDing

Ummmm, a Hollywood movie right here—

15,000 minks were all infected with #COVID19 (100% antibody positive)

…then silence…

But 2 months later… ➡️ 75% of the minks were suddenly all #SARSCoV2 reinfected again.

(Study brought to you by: Denmark’s CDC).
biorxiv.org/content/10.110…

2) “genome sequencing showed that the virus circulating during this re-infection was most closely related to virus identified in the first outbreak on this farm but additional sequence changes had occurred.”

➡️ it was related to original (not some foreign variant), but mutated.

3) “Animals had much higher levels of anti-SARS-CoV-2 antibodies after re-infection than at free-testing.”

➡️ second infection boosted antibody levels.

4) “Thus, following recovery from an initial infection, seropositive mink rapidly became susceptible to re-infection by SARS-CoV-2.”

➡️ **rapidly became susceptible to reinfection** stood out. 👀

5) “Thus, viruses in farms infected after Farm 4… were nearly all derived from … Farm 4”

➡️ it was a variant that caused it, but a locally derived variant. Not even some variant from a faraway place.

6) Denmark CDC purposefully did not cull all the minks from Farm 4. They wanted to study Reinfection. Hence they tested antibodies and did PCR tests repeatedly to try to find infections. Antibodies prevalence stayed at 100% (it did not wane)… yet reinfection still occurred.

7) The Danish CDC authors separately noted that “Furthermore, only about 50% of people in Denmark, who were over 65 years of age and had been infected with SARS-CoV-2, were found to be protected against re-infection” in an earlier study. pubmed.ncbi.nlm.nih.gov/33743221/

8) I’ve mentioned this previous study before… Denmark studied reinfection in *4 million* people who were formerly confirmed positive. 80% protection overall, but only 47% protection from reinfection among age >=65.

https://twitter.com/drericding/status/1372647243560464385

9) To be clear— this Danish reinfection study was the largest study in the world, literally.

https://twitter.com/drericding/status/1372647251475116033

10) recurrent #COVID19 has been established in healthcare workers in Brazil 🇧🇷 as well. At least one was formally a reinfection (others didn’t have sequencing to determine the variant). And there was “enhanced severity”.

pubmed.ncbi.nlm.nih.gov/33589297/