(WXYZ) — Last month, we told you about Sheri Houghland, a local healthcare worker who came down with COVID even though she was vaccinated.
RELATED: Why data around 'breakthrough' cases can show the vaccine works
"I broke the CDC rules and got a little overly confident and ended up spending some time with a friend who was unvaccinated indoors, without masks," Houghland said.
She had only mild symptoms and recovered quickly.
While breakthrough cases can happen, they are incredibly rare. And so, a bigger question looms around Houghland's incident. Had she lost immunity?
"As a nurse, I’ve been vaccinated, really one of the first people in the community that’s been vaccinated," Houghland said. "I’ve been vaccinated since about November."
As of Tuesday, 45% of people in Michigan age 12 and over are fully vaccinated. The news comes as our state sees its COVID numbers — and deaths — finally drop. But we all want to know – when will we lose our immunity?
"If a large proportion of vaccinated individuals have a significant drop in the neutralizing antibody fighters — or the amount of immunity — they’re going to probably start recommending boosters," said Dr. Joel Fishbain, an infectious disease specialist at Beaumont Health.
A booster is a second — or third, or fourth, or fifth — shot after the original introduction of an antigen.
"After the immune system sees an antigen — an antigen is anything foreign to our body, whether it’s a vaccine, a medication, or any foreign particle, like pollen, or a bee sting etc — upon re-exposure the immune system has a more significant response because its already seen it before," said Dr. Leonard Johnson, an infectious disease specialist at Ascension St. John in Detroit.
Currently, the FDA has only approved two shots for Moderna and Pfizer and one for Johnson & Johnson.
That means you can’t just show up at a CVS and demand a third shot because you’re concerned about immunity.
But right now – each of the pharmaceutical companies are in the midst of studying those additional booster shots. Pfizer began testing third-shot boosters in February. Moderna says they hope to have a booster available in the fall. None have put in an emergency authorization application with the FDA.
"I know everybody wants answers, it’s too early and it’s sort of day-by-day, we get more information and that’s what we’re stuck with," said Fishbain.
Researchers still don’t know how long our protection against the virus lasts once we’re fully vaccinated, that’s why experts continue to encourage social distancing and other precautions.