READ THIS NEXT: Boosters Won’t Protect You Against Omicron If You’ve Done This, Study Finds.ae0fcc31ae342fd3a1346ebb1f342fcb The COVID vaccines have shown themselves to be remarkably effective, particularly when it comes to preventing hospitalization and death. But experts have also said that vaccines have protective powers beyond that. According to the CDC, unvaccinated people might also be more at risk of developing symptoms that don’t go away than those who have received their shots. This persisting problem is known as long COVID and covers a wide range of long-term health problems, including fatigue, fever, and brain fog, but researchers are still working to understand the full scope of the condition. The U.S. Government Accountability Office (GAO) says it is estimated that anywhere from 7 to 23 million people in the country have already developed long COVID. The number is hard to pinpoint, as long COVID is not easy to diagnose. “There is no test to diagnose post-COVID conditions, and people may have a wide variety of symptoms that could come from other health problems. This can make it difficult for healthcare providers to recognize post-COVID conditions,” the CDC explains. But while it was believed that vaccines did provide significant protection against long COVID, new research is now casting doubt. A study from the Department of Veteran Affairs shows that vaccines may not offer substantial protection against post-COVID conditions. The researchers for the study, which was published May 25 in the Nature Medicine journal, looked at nearly 34,000 vaccinated individuals who had had a breakthrough COVID infection in 2021 and compared them to around 113,000 people who had been infected but not vaccinated, and more than 13 million people who had not been infected at all. According to the study, the previous COVID shots for those with breakthrough infections only offered “partial protection” against long COVID, cutting the likelihood of long-term symptoms by just 15 percent. “We’re literally solely reliant, now almost exclusively, on the vaccine to protect us and to protect the public,” Ziyad Al-Aly, MD, lead author and chief of research and development service at the Veteran Affairs’ St. Louis Health Care System, told Nature. “Now we’re saying it’s only going to protect you 15 percent. You remain vulnerable, and extraordinarily so.” The researchers also compared lingering symptoms like brain fog and fatigue in vaccinated and unvaccinated people for up to six months after they were initially diagnosed. According to the study, there was no difference in the severity of those symptoms between either group. RELATED: For more up-to-date information, sign up for our daily newsletter. There were limitations to Veteran Affairs study, however—including the fact that researchers did not analyze breakthrough infections during the Omicron surge. “We have no data on whether Omicron causes long COVID,” Steven Deeks, MD, an HIV researcher at the University of California, San Francisco, told Nature, adding that the findings “apply to a pandemic that has changed dramatically.” But overall, the researchers for the study say that “reliance on [vaccination] as a sole mitigation strategy may not optimally reduce long-term health consequences of SARS-CoV-2 infection.” Fortunately, health experts are already looking toward other solutions. As Reuters reported in March, leading drugmakers such as GlaxoSmithKline, Vir Biotechnology, and Humanigen have already started looking at the possibility of developing treatments that target long COVID. Scientists are also trying to uncover the underlying cause of long COVID, which could help move the development of treatments along. “We are getting to the stage where we are getting traction, and for people suffering, we are getting treatments tested,” David Strain, a University of Exeter Medical School lecturer, told Reuters. “Hopefully we will have things we can we offer them to get their lives back to normal in the near future.” READ THIS NEXT: Dr. Fauci Just Issued This Major Warning About Long COVID.