British researchers revealed that vaccination reduces the chances of suffering from symptoms of long COVID.

28,356 adults aged 18 to 69 who received at least one dose of adenovirus vector or mRNA vaccine after testing positive for SARS-CoV-2 were included in the study. The average age of the participants was 46, with a follow-up period of 141 days after the first vaccine dose and 67 days after the second dose. 

About a quarter of participants reported long COVID symptoms and approximately 17% of participants reported "difficulty of activities" minimum of once during the follow-up period. One dose of vaccine was linked with an initial 12.3% decrease (95% CI -19.5 to -4.5, P=0.003) in the odds of activity-limiting long COVID, and a second dose was associated with an initial 9.1% decrease (95% CI -15.6 to -2.1, P=0.01), followed by a 0.5% decrease per week until the end of follow-up.

Adults who were first infected with the virus and then received a COVID-19 vaccine showed an initial reduction of 12.8% (95% CI -18.6 to -6.6, P<0.001) in the odds of long COVID with the first dose of the vaccine, while an initial decline of 8.8% (95% CI -14.1 to -3.1, P=0.003) was observed with the second dose, followed by a 0.8 % reduction every week for the next 9 weeks.

Long COVID trajectories showed no significant difference between individuals who received the mRNA vaccine and those who were given the adenovirus vector vaccine.

The authors suggested that more research was needed to better understand the role of vaccination in the context of the Omicron variant, as well as to investigate the biological mechanisms involved in the improvement of Covid symptoms after vaccination, which could aid in the development of newer COVID therapeutics.

(MedPage Today May 18, 2022)