Sharp Decrease in Long Covid Symptoms for COVID-19 Patients

Vaccination after infection of SARS-CoV-2, the virus responsible for COVID-19, is associated with a decrease in long covid symptoms, and finds a large study of UK adults published today by The BMJ.

They told that causality cannot be inferred from this observational evidence, but say that vaccination “may contribute to a reduction in the population health burden of long covid, at least in the first few months after vaccination.”

Link Between COVID-19 Vaccination and Long Covid Symptoms

Vaccines against COVID-19 are effective in reducing the rates of infection, transmission, hospitalization, and death. Evidence also suggests that long covid is reduced in those who were infected after vaccination, but the effectiveness of vaccination on pre-existing long covid is less clear.

‘Evidence also suggests that long covid is reduced in those who were infected after vaccination, but the effectiveness of vaccination on pre-existing long covid is less clear.’

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The latest UK Office for National Statistics (ONS) survey shows that 44% of long covid reporters have had symptoms for at least a year, two-thirds of whom report symptoms severe enough to limit your daily activities.

So a team of researchers set out to estimate associations between COVID-19 vaccination and long covid symptoms in adults with COVID-19 infection before vaccination.

They were based on ONS data for 28,356 adults aged 18 to 69 years (mean age 46; 56% women; 89% white) who received at least one dose of COVID-19 vaccine dose after testing positive for the infection.

They then tracked the presence of long covid symptoms during a seven-month follow-up period (February to September 2021). Long covid symptoms of any severity 6,729 participants (24%) reported by at least once during follow-up. Before vaccination, the odds of experiencing long covid changed a little over time.

A first vaccine was associated with an initial 13% decrease in the odds of long covid, but it is unclear from the data whether this improvement was sustained over the next 12 weeks, until a second dose of vaccine was given.

Receiving a second dose of the vaccine was associated with an additional 9% decrease in the odds of long covid, and this improvement was maintained at least over a median follow-up of nine weeks.

Similar results were also found when the focus was on long covid severe enough to result in limitation of daily activities.

Findings of the Research

Due to the observational design of the study, causality cannot be inferred, nor can the investigators rule out the possibility that other unmeasured factors, such as those related to starting a second dose of vaccine, may have affected their results.

However, the results were consistent after accounting for sociodemographic characteristics, health-related factors, vaccine type, or duration from infection to vaccination, suggesting that they stand up to scrutiny.

As such, the researchers say, "Our results suggest that vaccination of previously infected people may be associated with a reduction in the prolonged covid burden on population health, at least in the first few months after vaccination."

They call for more research into the long-term relationship between COVID-19 vaccination and long covid, and studies "to understand the biological mechanisms that underlie any improvement in symptoms after vaccination, which may contribute to the development of therapies for prolonged COVID." .

Researchers ask the question that are vaccines a potential treatment for prolonged covid. They have also acknowledged that benefits are possible in some individuals, not all, and say that the mechanisms underpinning changes in long-lasting COVID symptoms after vaccination are not yet fully understood.

Until a clear explanation is found, they say vaccination to reduce the risk of reinfection remains important for people with prolonged covid, and the evidence so far suggests the benefits are likely to outweigh any harm.

“Unfortunately, many unknowns remain about the long term prognosis of long covid, including the effect of booster vaccines or recurrent covid-19,” they write, and they call for more research “before we can hope to predict the effects of vaccination on individuals.”

Source-Medindia