New variants concern health officials as factors impacting booster shots evolve

TAMPA, Fla. - Doctors are working out how to get FDA-authorized third doses into immuno-compromised people to protect them against COVID-19, as the federal government considers booster shots for the rest of the general public in an evolving pandemic.  

"We are waiting to find out more information about exactly when that third booster would become available," said Dr. Jason Wilson, an emergency room physician at Tampa General Hospital and USF Health. "What we would expect to see is the most vulnerable patients would first eligible and then it would kind of open up to the rest of the population after that, so very similar to the first vaccine rollouts we saw."

TGH is among many hospital systems working on a plan for people who got organ transplants, cancer patients and others with auto-immune conditions. The delta variant sparked federal health officials to act fast to bump up their protection.

"We clearly know that those folks respond and they do really well, but we want them to get as good as everybody else. So getting the third dose is important for them," said Dr. Michael Lauzardo, the deputy director at the Emerging Pathogens Institute at the University of Florida.

MORE: As officials discuss boosters, confidence in vaccines varies across Bay Area

But whether you’re immunocompromised or not, doctors are quick to point out, talk of a third dose does not mean the current vaccines don’t work.

"I know people hear it's 95% effective against the first variant and then variably effective against other variants. It's still the most effective vaccine we've ever had," said Dr. Peggy Duggan, TGH’s chief medical officer. "So no one should be discouraged if the numbers drop a little as far as effectiveness, it's incredibly impactful."

Even though virus mutation is natural, there are still enough unvaccinated people out there for the virus to have more chances to mutate for even longer.

"Because we couldn't finish getting everybody vaccinated, people were hesitant for a variety of different reasons. We gave an opening to the virus. So in other words, we ended up allowing that virus to kind of mutate and develop and then kind of spread to other people," said Lauzardo.

RELATED: COVID-19 booster vaccine: FDA approves 3rd shot for immunocompromised

USF Health virologist Dr. Michael Teng said scientists are tracking several emerging strains, like the lambda variant. He shared what information current studies are finding in vaccinated people.

"It seems to show that the lambda variant is neutralized, at least to the same extent as the Delta variant. So there's not really a difference in terms of immune evasion. Right now, that's not really a concern that the variants seem to be at least covered mostly by the current vaccines," said Teng. "Pfizer and Moderna have both developed vaccines to that have the mutations in some of the variants in them and they're testing those. So when it does come to a point that maybe we get another variant at some point that has a lot more immune evasion, we can pretty quickly pivot to a variant-specific vaccine."

So while third doses roll out of vulnerable groups, public health experts want the general vaccinated public to know one important factor.

"I think an important thing to remember is that for the average person who is healthy, who's been vaccinated to protect themselves from getting COVID or getting a serious form of COVID, two vaccines is probably enough based on what we know now," said Lauzardo.

Doctors and public health scientists said the virus is constantly changing so there are no absolute answers. Doctors said the vaccines protect people, so they say that will continue to be their message to the public.