Watch: Long Covid chances almost halved by double vaccination, study finds
Over the past 18 months, the world's scientists have discovered enough about COVID-19 and the novel coronavirus it causes to create effective vaccines, and understand the characteristics of the highly infectious airborne disease.
But while many lives have been saved, and many who catch COVID recover within four weeks, some endure debilitating symptoms for months. This condition is known as Long Covid, and can occur even when symptoms were originally mild, or the person is otherwise healthy.
Now, new research from King's College London has found that being fully vaccinated with both jabs dramatically lessens the chances of developing Long Covid, as well as offering protection from very serious illness.
Those who had been double-vaccinated had 50% less chance of developing symptoms lasting longer than four weeks.
To date, 78.9% of over-16s in the UK have had both vaccinations.
The research was published in The Lancet Infectious Diseases, and concluded, "To minimise SARS-CoV-2 infection, at-risk populations must be targeted in efforts to boost vaccine effectiveness and infection control measures."
The researchers also suggest that the findings 'might support caution' over relaxing physical distancing measures, particularly around older or frail people, even if they are vaccinated.
The study analysed data from the UK's ZOE Covid study app, which tracks self-reported symptoms, tests and vaccines. Between Dec 2020 and July 2021 it tracked the health of 1.2 million adults who had received one coronavirus jab and 971,504 who had two jabs during the period.
Only 0.2% of double-jabbed people said they had a Covid infection after vaccination (2,370 cases)
Of the 592 fully vaccinated people with Covid, 31 (5%) developed Long Covid - but in the unvaccinated group it was more than double the number, at 11%.
It's another piece of proof - if any were needed - that vaccines genuinely ease symptoms.
In July, according to the Office for National Statistics, around 945 000 people in the UK (1·5% of the population) had self-reported long COVID, including 34 000 children aged 2–16.
"Prevalence was greatest in people aged 35–69 years, girls and women, people living in the most deprived areas, those working in health or social care, and those with another activity-limiting health condition or disability," said the researchers.
Long Covid isn't just a matter of feeling a bit ill, either, they point out.
"At one year, COVID-19 survivors had more mobility problems, pain or discomfort, and anxiety or depression than control participants" they wrote.
The most frequently reported symptoms of Long Covid were fatigue or muscle weakness, while just under 50% reported having at least one symptom, "such as sleep difficulties, palpitations, joint pain, or chest pain, at 12 months.
"The study shows that for many patients, full recovery from COVID-19 will take more than one year, and raises important issues for health services and research."
The study also found a low number of sufferers (0.4%) had participated in any kid of professional rehabilitation programme. The researchers cited the possibility of 'poor recognition' of the condition by medics, and a lack of obvious referral pathways to offer support.
As yet, the causes of Long Covid have not been pinpointed.
It has been mooted that the symptoms are caused by the live virus reactivating in the body, or that it's an autoimmune problem - the body attacking itself to repel the invasive virus.
Others think it could be cause by an under-active immune system - but to date, there is no consensus.
Until the causes - and cures - of Long Covid are clearer, it's evident that the best way to protect yourself and those around you is to have both vaccinations and keep using protective methods such as masks in crowded areas, alongside social distancing.
Watch: 'I wish I'd got my jab as soon as it was offered.'