BALTIMORE (WMAR) — Nearly 55 percent of eligible Marylanders have gotten at least one dose of a COVID-19 vaccine but the daily average of shots administered has started declining.
Health experts say that could increase the likelihood of needing booster shots in the future.
"If you’re trying to prevent a forest fire, and you can spray something onto a tree that keeps it from burning, you have to spray more than one every 10 trees to really prevent the fire from spreading," said Dr. Andrea Cox, Infectious Disease Specialist at Johns Hopkins Hospital.
Cox said that’s an easy way to think of what’s happening now, with vaccinations during the continued spread of COVID-19 and highly transmissible variants.
"The more people the virus infects, the more opportunities it has to try to find different ways to win the fight and we don’t want to give it that opportunity," said Cox.
While the vaccines have been very effective at preventing hospitalization and death, data from Pfizer shows it’s reduced against the South African variant so Cox said the slower people get vaccinated, the more likely it is that booster shots will be needed.
Pfizer and Moderna are both exploring updated booster shots. The cutting edge MRNA technology makes that easy.
"You can think of it like computer code essentially. It's just telling cells 'Make this spike protein' and you can change that code very subtly," said Dr. Kirsten Lyke, a Professor of Medicine at the University of Maryland School of Medicine Center for Vaccine Development.
The University of Maryland School of Medicine participated in the Pfizer phase one clinical trial, and are now using some of those volunteers for the booster study.
"We’ve already given them a booster and we are following them and sending samples to Pfizer so that they can look at the immune response," said Lyke.
Health experts say it's possible people will need to get vaccinated against the coronavirus annually, like the flu.
"We can do the science now so that we can make plans for, say next autumn, if we need boosters," said Lyke.
It's still unknown how long the vaccines protect fully vaccinated people but Pfizer and Moderna data has shown efficacy after six months continues to be very strong.