Michelle Chason, a reiki master in Tallahassee, Florida, was diagnosed with COVID-19 on June 15, 2020. First, she developed dry mouth. Then came the nasty vertigo spells that led to spinning rooms and blackouts.

Chason tested negative a month later, but she still didnt feel right. The left side of her face tingled. She felt chest pain, had debilitating brain fog, and started experiencing short-term memory problems. Four months after her initial diagnosis, in October, Chasons physician told her she was suffering from long COVID.

When the vaccines started to roll out, Chason planned to wait and see how other long-haulers reacted before rolling up her sleeve. But on Feb. 10, her doctor offered her the Pfizer vaccine and she got the shot.

Four days after the first dose, Chason said, the symptoms vertigo, nausea, loss of appetite, chills hit like a lightning bolt. I went through every single thing I had been dealing with since I had COVID, Chason said.

A few days later, the vast majority of her long COVID symptoms the brain fog, chest pain and face tingling cleared up. Im better, I feel better. Im not 100% to pre-COVID days, but Im close, Chason told HuffPost.

Around the world, many other people with long-haul symptoms a condition now clinically defined as post-acute sequelae of SARS-CoV-2, or PASC have reported similar experiences after getting a vaccine.

A recent informal poll from Survivor Corps, a Facebook community of COVID-19 survivors, found that 36% of people with long-haul symptoms noticed improvements in their condition after vaccination. About 50% remained the same. Other unofficial surveys have also estimated that about a third of patients with long COVID feel better after getting a vaccine.

At the same time, many others with PASC are hesitant about getting vaccinated , concerned the shot could exacerbate long-haul symptoms. They worry about being hit with side effects on top of the devastating long COVID pain.

In general, the vaccines dont seem to worsen long COVID symptoms. The Johnson & Johnson trials enrolled several people who previously had COVID-19, and those people did not have a re-inflammatory reaction or particularly worse effect, according to F. Perry Wilson , a Yale Medicine physician and researcher at Yale School of Medicine.

But doctors know very little about PASC and how those with the condition might respond to a vaccine. So while it seems like the shot could improve long COVID symptoms in a small group of people, so much of what we currently know is based off anecdotes.