LOS ANGELES (KABC) -- It can be very frustrating for people who experience lingering symptoms months after they were initially diagnosed with COVID-19. For these long-haulers, as they're called, not knowing when those symptoms will subside is what's most troubling.
But now, some people are getting relief after getting the coronavirus vaccine.
Juliana Shain of Simi Valley came down with COVID-19 before Christmas. Since then, brain fog and fatigue plagued her - but even more serious symptoms have cropped up
"I developed something called POTS , which is where anytime you go to stand up, your blood pressure is so low, it can't get up to the top of your head in time. So you start to pass out," she said. "When there's no end in sight and you start to think like this could be my life, it's very, very depressing."
Shain is a veterinary care worker who put off getting the vaccine because of her symptoms. But six days ago, she got her first dose. Then three days later she said, "I had a spring in my step. My mood was better and I had energy!"
Similar COVID long-haulers have reported a lessening of symptoms. Cedars-Sinai infectious disease expert Dr. Priya Soni has some theories as to why.
"One theory is that there might be some leftover viral fragments causing the immune system to be in a somewhat inflammatory state," she said.
Another possibility is that old viruses that stayed dormant in the body may have become active after a COVID infection. Soni said the only way to know if a vaccine helps is to do randomized, controlled studies to rule out the placebo effect.
"Without doing the clinical trials, we may be missing out on the true reason why this is happening," she said.
Soni said the important message is that everyone -- including long-haulers -- should get vaccinated.
"We know that there are some folks that are getting re-infected with the virus," she said. "And so it's really important that if you're able to go ahead and get vaccinated."
"As we keep going, those of us who are getting better will have stories and we'll have advice. And it sounds like there is light at the end of the tunnel. That's the most important thing to know," Shain said.
Understanding the link between COVID-19 and its long-term effects may unlock treatments to other post-viral and auto-immune syndromes. These findings may help science in ways beyond the pandemic.
WATCH | What is a COVID-19 long hauler?