The data confirms the large body of research showing that vaccination significantly reduces the risk of death or serious illness. But there was more ambiguity regarding long Covid.
Six months after their initial diagnosis of Covid, the vaccinated people in the study had only a slightly reduced risk of long-term illness from Covid – a total of 15 percent. The greatest benefit seemed to be in reducing blood clotting and lung complications. However, there was no difference between vaccinated and unvaccinated when it came to long-term risks of neurological problems, gastrointestinal symptoms, kidney failure and other conditions.
“That was disappointing,” said Ziyad Al-Aly, lead author and director of research and development services at VA Saint Louis Health Care System. “I was hoping to see vaccines offer more protection, especially given that vaccines are our only line of defense these days.”
“Long covid” refers to the constellation of symptoms that many people have reported months after their initial infections. At the beginning of the pandemic, some patients complaining of persistent symptoms were dismissed by doctors who thought the manifestations might be psychological. But the condition has since become a major concern for the medical community.
The World Health Organization has defined post-Covid syndrome as symptoms that last at least two months and cannot be explained by alternative diagnoses. It cited evidence suggesting that up to 20 percent of the half billion people worldwide estimated to be infected with coronavirus could experience medium- and long-term effects.
This week, the Centers for Disease Control and Prevention released new estimates of the number of episodes from the syndrome in the United States, suggesting that it affects one in five adults under the age of 65 who have Covid and one in four those over the age of 65 is. People in both age groups were twice as likely as uninfected people to develop respiratory symptoms and lung problems, including pulmonary embolism, the CDC found. Those in the older age group had a higher risk of developing kidney failure, type 2 diabetes, neurological disorders, and mental health problems.
The Veterans Affairs study, believed to be the largest medical record-based peer-reviewed analysis in the United States of long-Covid, looked at patients receiving either two doses of the Moderna or Pfizer-BioNTech vaccines or a dose of the Johnson & Johnson vaccine. The effects of booster shots have not been evaluated. While the study population included a wide range of ages and racial and ethnic backgrounds, it was older, whiter, and more male than the United States as a whole.
The VA study also had no way of saying how different variants might alter the risk of a long covid. For example, these breakthrough infections occurred at a time when alpha, delta, and earlier variants were at high levels in the United States. It does not cover the period when the Omicron variant and its subvariants entered circulation in late 2021.
How long is Covid accelerating a revolution in medical research?
The findings add to the debate similar analyzes from the UK, Israel and other countries, which have shown conflicting results regarding whether vaccines protect against long-term Covid.
For example, a British study published in the medical journal Lancet, based on self-reported data from an app, showed a 50 percent reduction in risk in those who were vaccinated. On the other hand, a paper by Oxford University researchers, based on electronic records from the United States, found that vaccination did not appear to reduce the risk of long covid for most symptoms.
The question of vaccines and long Covid has been crucial for doctors. Some patients have claimed a vaccine cured them, while others have avoided the shots for fear of triggering symptoms.
Igor Koralnik, Northwestern Medicine’s chief of neuroinfectious diseases, said recent research suggests neither is true. In an article published Tuesday in the Annals of Clinical and Translational Neurology, Koralnik and his colleagues found that 77 percent of the 52 patients with long-term Covid follow them had been vaccinated against the coronavirus, but the vaccinations did not appear to have any positive or negative effects on cognitive function or fatigue.
“There is a neutral effect of vaccination. It didn’t cure Covid for long. It didn’t make Covid worse for long,” Koralnik said.
At Dartmouth Hitchcock Medical Center’s Post-Acute COVID Syndrome Clinic, Christina Martin, a nurse beforehand, said her staff have noticed a “worrying trend” of vaccinated people with breakthrough infections and the development of a long Covid since November.
When the clinic started a year ago, she said, they expected fewer new patients to be treated at that point as more people were getting vaccinated. Unfortunately, they have seen the opposite, with increasing patient numbers.
“We now have the feeling that Covid will stay here for a long time. … This will have a profound impact on our healthcare system and resources,” Martin said.
David Putrino, a longtime Covid researcher who serves as director of rehabilitation innovation at Mount Sinai Health System in New York, shares these concerns. He fears that public health leaders are not taking the current surge seriously enough because they are not taking into account the risks of a long Covid.
Putrino said demand for appointments at his medical center’s long Covid clinic continues to increase and he doesn’t expect a slowdown any time soon. The clinic has treated approximately 2,500 patients since opening in May 2020.
“We have failed in our health message that death is not the only serious consequence of Covid-19 infection,” Putrino said. “. . . I am very concerned that this will lead us to a continuation of this mass-disabling event that we have been witnessing for a long time.”