The risk of developing long COVID decreased as the pandemic unfolded, in part due to vaccination, according to US research. The study, which tracked almost half a million people infected with COVID-19 in the US, found that rates of long COVID decreased as the dominant virus strains changed from the original strain, through to delta and omicron, and they were also lower in vaccinated people. The research found there were 5.23 fewer instances of long COVID for every 100 people during the omicron era than during the pre-delta and delta eras combined. They found that 72% of the drop in long COVID was due to vaccination. The authors point out that while the risks decreased during the pandemic, the risk of long COVID remained substantial even among vaccinated people infected during the omicron era.
