Researchers at King’s College London found that a double dose of the antidote in adults can halve the odds of developing long COVID, if they should become infected. Severity of symptoms was also reduced by nearly a third, at 31%.
People aged 60 and over saw perhaps the more crucial benefits, as those who had two shots were more likely to report no symptoms at all compared to unvaccinated seniors.
Published on Wednesday in the Lancet, researchers analyzed health data from more than 2 million patients between December 2020 and July 2021, as part of the UK Zoe COVID Symptom Study initiative, which allows participants to report on their condition via smartphone app.
Research lead Dr. Claire Steves, of King’s College, suggested that "double vaccination significantly reduces the risk of both catching the virus and, if you do, developing long-standing symptoms."
Steves added in a statement, "Among our frail, older adults and those living in deprived areas the risk is still significant and they should be urgently prioritized for second and booster vaccinations."
Results showed that approximately 6,030 app users reported testing positive for coronavirus at least 14 days after their first dose, and 2,370 became sick at seven days or more after their second.
Vaccinated study participants were also half as likely to develop multiple symptoms associated with the virus, such as cough, fever, headache, fatigue and loss of smell, to name a few, and those who did reported milder effects than unvaccinated patients.
Notably, they found sneezing was the only symptom more common in infected people with one dose of the vaccine, compared to those with none.
"Vaccinations are massively reducing the chances of people getting long Covid in two ways," said King’s College professor Tim Spector, one of the study’s authors. "Firstly, by reducing the risk of any symptoms by eight- to 10-fold, and then by halving the chances of any infection turning into long Covid, if it does happen.
"Whatever the duration of symptoms, we are seeing that infections after two vaccinations are also much milder, so vaccines are really changing the disease and for the better. We are encouraging people to get their second jab as soon as they can," Spector added.
Their study did not include data from children, who are not yet approved for the vaccine in the UK nor here in the US — though they are expected to become available to those 12 and under by mid-winter. Cases surged five-fold within the demographic during the past month, climbing from 38,000 the week ending July 22 to nearly 204,000 as of Aug. 26, according to the American Academy of Pediatrics.
The Centers for Disease Control and Prevention has said they are monitoring potential cases of long-haul COVID in kids, even among those who experienced only mild symptoms during infection. "We are seeing long COVID symptoms [in children], mostly fatigue and headache," said CDC director Dr. Rochelle Walensky earlier this month.
As of one week ago, nearly 4.8 million children in the US have tested positive for COVID-19 since the pandemic began, out of a total case load of 39.5 million — and counting.