On we go with the CV-19 research, even though people generally consider the epidemic to be over.
This large study from Qatar compared protection from prior infection to that from vax. Adaptive immunity from infection was more durable and stronger than that from vax in regard to protection against a subsequent infection, but vax had an ongoing effectiveness against hospitalization and serious disease. (Medrxiv Study)
A third dose of mRNA vaccine restored neutralizing antibodies to post-early dose levels in people with no prior CV-19 infection, but not in those with a prior infection, suggesting a limit to how many doses will be helpful, particularly given the lessening effectiveness of earlier doses. The prior-infection group had a higher response to earlier doses than did the naive group. (Medrxiv Study)
According to this study, there was no difference in viral load in vaxed and unvaxed persons, including when accounting for symptom level. (JID Article)
The use of rapid antigen tests is widespread, but there has been some criticism of their potential for false negatives. This study looked at whether RAT negatives were associated with infectious persons. They almost never were, indicating that these tests are actually superior to PCR ones for purposes of managing the epidemic. They are far less likely to lead to unnecessary isolation. (Medrxiv Study)
For people who were infected early in the epidemic, antibodies were detected for up to 18 months post-infection, but the antibodies were less effective against recent variants. (JID Article)
Omicron cases appeared to have significantly shorter hospital lengths of stay across all age groups, according to this study from Australia. For some bizarre reason, however, the potential effect of vaccination was not included in the analysis. (Medrxiv Study)
This article claims that mobility rates were a significant factor in case spread during the Omicron wave, but shows really pretty minor impacts and the analysis fails to account for multiple substantial confounding factors. While it is probably true that less mobility means fewer contacts and that in turn could lead to less transmission, household transmission continues to be the single largest source of cases, so mobility likely has mixed effects. (Medrxiv Study)