Thread by @Marc_Veld

Good pre-print!

Viral kinetics of sequential SARS-CoV-2 infections

Comparing primary infection with secondary infection. Is the second one less, more or similarly dangerous?

medrxiv.org/content/10.110…

94,812 longitudinal RT-qPCR measurements from anterior nares and oropharyngeal swabs. Compared the SARS-CoV-2 viral kinetics of first vs. second infections, adjusting for viral variant, vaccination status, and age.

#immunology101 would strongly suggest that relative to first infections, second infections have reduced pathogen burden, faster clearance, especially in those who received a vaccine dose in addition. But some have contributed near magical properties to SARS-CoV-2.Wee

Not unexpectedly: the secondary SARS-CoV-2 infection shows less viral burden, and is reduced in time in the upper respiratory tract.

If a person was also vaccinated between first and second infection; the clearance was even quicker:

If you are genetically predisposed to clear a virus more quickly, you are likely to do so as well a second time. Also that makes sense.

What we see is what is expected; our immune system works as it should: providing protection against SC2, generating and responding with a quicker memory response.
The quicker resolution will mean shorter transmission period, less likely to get ill, less duration of symptoms.

What would be nice to see is also dissemination data: In primary infection the virus is more likely to escape immune control and affect more tissues, this should be much curtailed upon subsequent infections.

A large part of the quick clearance correlates strongly with activated T cells. Those not in the blood but already at the site of infection will even enhance this response.

https://twitter.com/Marc_Veld/status/1630598165735829505?s=20