A healthcare doctor prepares a dose of Johnson & Johnson’s Coronavirus Disease (COVID-19) vaccine for a commuter during the opening of MTA’s public vaccination program on the 179th Street subway station in the Queens borough of New York City in front. USA, May 12, 2021.

Shannon Stapleton | Reuters

The National Institutes of Health announced Tuesday that they had started an early-stage clinical trial looking into what happens when an adult fully vaccinated with a type of Covid-19 vaccine like Pfizer’s is boosted with another vaccination about three to four months later.

The study will enroll approximately 150 adults who have received any of the three Covid vaccination regimens currently available under the Food and Drug Administration’s emergency approval: Johnson & Johnsons, Moderna, or Pfizer.

Federal health officials said people who have not yet received an approved vaccine are also eligible to enroll in a separate group for the study. These volunteers will receive two doses of the vaccine from Moderna and will receive a booster dose of one of the three vaccines around 12 to 20 weeks later, officials said.

“Although the vaccines currently approved by the US Food and Drug Administration offer strong protection against COVID-19, we must prepare for the possibility that booster vaccinations will be required to counter declining immunity and step up with a developing virus hold, “said Dr. Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases, an NIH agency.

“The results of this study are intended to inform public health policy decisions about the potential use of mixed vaccination schedules in the event that booster doses are indicated,” he added.

The study is taking place as drug makers and some scientists are now saying that people will likely need a booster dose of Covid-19 vaccines and possibly additional vaccinations every year, just like they would with seasonal flu.

Pfizer and Moderna’s Covid-19 vaccines currently require two doses three to four weeks apart, while Johnson & Johnson vaccines only require one prick. All three vaccines have been shown to be highly effective against Covid, although company executives now expect this strong protection to wear off over time.

Dr. Peter Marks, director of the FDA’s Center for Biologics Evaluation and Research, said last month that Covid-19 booster vaccinations could be required for fully vaccinated individuals within a year. The current versions of the Pfizer-BioNTech and Moderna vaccines are highly effective in preventing Covid and also appear to protect against the variants circulating in the United States, he said.

“So, hopefully, you know, it would be nice if it turned out it would be a year before someone needed a refresher,” said Marks on the 18th of school and junior journalists.

“But we still don’t know,” he added. “It could be more, it could be a little less, but … that’s just something we need to find out over time.”

Each vaccine group in the NIH study will enroll about 25 people ages 18 to 55 and about 25 people ages 56 and older.

Twelve to 20 weeks after their initial vaccination, participants in the study will receive a single booster dose of the Moderna vaccine.