Being vaccinated against Covid-19 halves the risk of developing long Covid, a large study by UK researchers has concluded.

A meta-analysis of 41 studies involving more than 860,000 patients from all over the world found that two doses of Covid-19 vaccine was associated with a significant 43% reduction in the risk of developing a ‘post Covid-19 condition’.

By contrast an increased risk of long Covid was among females, those over the age of 40, those with a high BMI and smokers, the paper in JAMA Internal Medicine said.

And co-morbidities such as asthma, COPD, type 2 diabetes, coronary heart disease, immunosuppression, anxiety and depression were also associated with increased risk, the team from the University of East Anglia reported.

Patients who were hospitalised during their acute long Covid infection are also at higher risk of having ongoing persistent symptoms, the analysis found.

Data suggests long Covid – defined as symptoms lasting 12 weeks or more – still affects some two million people in the UK.

Study lead Professor Vassilios Vassiliou, a consultant cardiologist at the Norfolk and Norwich University Hospital, said long Covid was a complex condition.

‘It affects people in different ways. Breathlessness, a cough, heart palpitations, headaches, and severe fatigue are among the most prevalent symptoms.

‘Other symptoms may include chest pain or tightness, brain fog, insomnia, dizziness, joint pain, depression and anxiety, tinnitus, loss of appetite, headaches, and changes to sense of smell or taste.’

He said in their analysis of what might make people more susceptible to having ongoing symptoms, it was ‘reassuring’ to see the impact of vaccination.

‘People who had been vaccinated had significantly less risk – almost half the risk – of developing long Covid compared to unvaccinated participants.

‘These findings are important because they enable us to better understand who may develop long Covid and also advocate for the benefit of vaccination.’

Co-author Dr Eleana Ntatsaki added said the findings would help teams to ‘better understand and serve this population with long term care planning, support for Long Covid clinics and increase awareness of the prevalence and impact of the condition.’

The Covid-19 Infection Survey, set up in April 2020 to provide weekly data on rates of circulating virus and new variants as well as the prevalence of long Covid, will be paused at the end of the month.

Plans on what surveillance system will replace the survey are yet to be announced.

This article first appeared on our sister publication, Pulse.