Long COVID
This paper from Italy found that people continue to recover taste and smell for at least three years after losing it due to COVID-19 infection.
This paper from USA said that children under 5 years old who had been infected with COVID-19 were 40% more likely to get RSV than controls.
Vaccines
Intranasal vaccines again look good! This paper from USA boosted some monkeys (who had already gotten two intramuscular doses of Moderna bivalent Classic/BA.5) with an experimental bivalent Classic/BA.5 adenovirus vaccine (like the AZ vaccine, and maybe even the actual AZ vaccine — they used a name which was really close but not quite the same as AZ’s research name). Some of the monkeys got an mucosal booster (either via nasal spray or via a nebulizer), and some got an intramuscular injection of Moderna bivalent. After fifteen weeks, the monkeys were given a hefty dose of XBB1.6. The monkeys which got the mucosal boosters did much better than the ones who got an intramuscular booster. The nebulized cohort had essentially no virus in the lungs; the nasal spray cohort had essentially no virus in the nose.
This paper from USA found that getting flu and COVID-19 shots at the same time was just as effective as getting them at different times.
COVID-Related Excess Death and Sickness
This paper from Italy found that people who had COVID-19 infections had a 65% greater risk of hypertension.
Pathology
This paper from UK found that first-episode psychosis diagnoses went up by 45% during the first year (approximately) of the pandemic.
This paper from Canada found that 42% of people with PTSD got better during the pandemic, while only 6% got worse.
This paper from USA found that transplanted kidneys from COVID-19-infected donors were pretty much just as good as kidneys from uninfected donors iff the donor did not die of COVID-19. If the donor died of COVID-19 (instead of with), then the Estimated Glomerular Filtration Rate was significantly lower.
Interestingly, they saw zero cases of the recipient catching COVID-19 from the donor kidney.
This paper from USA using UK data found that people who self-reported having childhood adversity were 23% more likely to be hospitalized with COVID-19 and 25% more likely to die from COVID-19.
Transmission
This paper from Costa Rica found that the infected person wearing a mask reduced the risk of passing COVID-19 onto a household member by 67%, while putting the infected person in their own bedroom dropped the risk by 78%.
Recommended Reading
This article summarizes all the bad things that a COVID-19 infection can do to you. (I actually have seen papers which found much more pessimistic odds of various Bad Things. As mentioned before, this spreadsheet lists hundreds of papers detailing long-term effects.)