Data from individuals infected with SARS-CoV-2 early in the pandemic add growing evidence to suggest that vaccination may help reduce the risk of long-term COVID-191.
Researchers in Israel report that individuals who have had both SARS-CoV-2 infection and doses of Pfizer-BioNTech vaccine were much less likely to report any of a range of common long-term COVID symptoms than individuals who were unvaccinated when they became infected. In fact, vaccinated humans were no more likely to report symptoms than people who had never captured SARS-CoV-2. The study has not yet been peer reviewed.
“Here’s another reason to get vaccinated if you needed one,” says co-author Michael Edelstein, an epidemiologist at Bar-Ilan University in Safed, Israel.
People with debilitating condition called long COVID continue to experience symptoms – such as fatigue, shortness of breath and even difficulty concentrating – weeks, months or years after SARS-CoV-2 infection. Some estimate that up to 30% of those infected, including many who were never hospitalized, have persistent symptoms.
Vaccination reduces the incidence of long-term COVIDs by preventing people from becoming infected in the first place. In theory, the shoots could also protect against the condition by minimizing the time the virus has free rein in the body during breakthrough infections. But so far, the few studies that have examined any Vaccines protect humans from prolonged COVID have had mixed results, says Akiko Iwasaki, a viral immunologist at the Yale School of Medicine in New Haven, Connecticut.
To investigate the long-term effects of the pandemic, between July and November 2021, Edelstein and his colleagues asked more than 3,000 people if they experienced the most common symptoms of prolonged COVID. All had been tested for SARS-CoV-2 between March 2020 and the study period.
The researchers compared the prevalence of each symptom with self-reported vaccination status and found that fully vaccinated participants who had also had COVID-19 were 54% less likely to report headaches, 64% less likely to report fatigue, and 68% less likely to report. muscle pain than their unvaccinated counterparts.
An attempt at long-distance covid?
Edelstein says his team’s study is the most “comprehensive and accurate” to date on vaccination and long-term COVID, and that the results reflect the results of other research, including a UK-based study2 from September last year, which showed that vaccination halved the risk of long-term COVID.
Claire Steves, a geriatrician at King’s College London, who led the British study, agrees that the Israeli data support previous findings. “It’s really good to see different study designs related to the same results,” she says.
Although the results of both British and Israeli studies show that vaccination reduces the risk of long-term COVID, she says that even fully vaccinated people are still at risk of developing the condition. And whether vaccination protects people against Omicron-induced long COVID is still unclear.
Either way, Iwasaki says these results are encouraging. “Long COVID is a terrible and debilitating disease. All the measures we can take to prevent long-term COVID are the key to limiting more suffering in the future,” she says. “Another reason to be vaccinated.”