Vaccination after SARS-CoV-2 infection linked to a decrease in long COVID symptoms

Vaccination after an infection with SARS-CoV-2, the virus answerable for COVID-19, is related to a lower within the probability of lengthy COVID signs, finds a big examine of UK adults revealed by The BMJ at this time.

They stress that causality can’t be inferred from this observational proof, however say vaccination “might contribute to a discount within the population health burden of lengthy COVID, no less than within the first few months after vaccination.”

Vaccines in opposition to COVID-19 are efficient at decreasing charges of coronavirus an infection, transmission, hospital admission, and loss of life. Proof additionally means that lengthy COVID is diminished in those that are contaminated after vaccination, however the effectiveness of vaccination on pre-existing lengthy COVID is much less clear.

The most recent survey by the UK’s Workplace for Nationwide Statistics (ONS) exhibits that 44% of people that report lengthy COVID have had signs for no less than one yr, two thirds of whom report signs extreme sufficient to restrict their day-to-day actions.

So a crew of researchers got down to estimate associations between COVID-19 vaccination and lengthy COVID signs in adults with SARS-CoV-2 an infection earlier than vaccination.

They drew on ONS knowledge for 28,356 adults aged 18-69 years (common age 46; 56% girls; 89% white) who acquired no less than one COVID-19 vaccine dose after testing optimistic for SARS-CoV-2 an infection.

They then tracked the presence of lengthy COVID signs over a seven month follow-up interval (February to September 2021).

Lengthy COVID signs of any severity have been reported by 6,729 members (24%) no less than as soon as throughout follow-up.

Earlier than vaccination, the percentages of experiencing lengthy COVID modified little over time.

A primary vaccine dose was related to an preliminary 13% lower within the odds of lengthy COVID, however it’s unclear from the info whether or not this enchancment was sustained over the next 12 weeks, till a second vaccine dose was given.

Receiving a second vaccine dose was related to an additional 9% lower within the odds of lengthy COVID, and this enchancment was sustained no less than over a median follow-up of 9 weeks.

Related outcomes have been additionally discovered when the main focus was on lengthy COVID extreme sufficient to lead to limitation of day-to-day actions.

Because of the examine’s observational design, causality can’t be inferred, nor can the researchers rule out the chance that different unmeasured elements, equivalent to these associated to take-up of a second vaccine dose, might have affected their outcomes.

Nevertheless, outcomes have been constant after taking account of sociodemographic traits, well being associated elements, vaccine sort, or length from an infection to vaccination, suggesting that they stand up to scrutiny.

As such, the researchers say: “Our outcomes recommend that vaccination of individuals beforehand contaminated could also be related to a discount within the burden of lengthy COVID on inhabitants well being, no less than within the first few months after vaccination.”

They name for additional analysis into the long run relationship between vaccination and lengthy COVID, and research “to know the organic mechanisms underpinning any enhancements in signs after vaccination, which can contribute to the event of therapeutics for lengthy COVID.”

Are vaccines a possible therapy for lengthy COVID, ask researchers in a linked editorial?

They acknowledge that advantages are potential in some people not all, and say the mechanisms underpinning modifications in lengthy COVID signs after vaccination are nonetheless not absolutely understood.

Till a transparent clarification is discovered, they are saying vaccination to scale back threat of reinfection stays vital for folks with lengthy COVID, and proof thus far means that advantages are more likely to outweigh any harms.

“Sadly, many unknowns stay about the long run prognosis of lengthy COVID, together with the impact of booster vaccines or recurrent COVID-19,” they write, and so they name for extra analysis “earlier than we are able to hope to foretell the consequences of vaccination on people.”