More data required on need for second booster shot against COVID-19, experts say

More data is needed before determining if healthy Americans will need a second dose of the COVID-19 booster to maintain immunity levels as the vaccine's effectiveness wanes over time, top Long Island medical officials said last week.

Last September, the Centers for Disease Control and Prevention recommended a booster shot at least six months after individuals had received their second dose of the original vaccine regimen to maintain strong protection against the virus. The CDC later lowered the waiting time to five months after completing the Pfizer or Moderna series and two months after taking the single dose Johnson & Johnson vaccine.

And a CDC report, released on Friday, found that the effectiveness of the booster to prevent COVID-19 began to wane four months after the shot.

Now nearly five months after booster shots were first approved, federal regulators have recommended a second round of shots only for the most severely immunocompromised individuals.

"The jury is still out on this question," said Dr. Bruce Farber, chief of public health and epidemiology for Northwell Health. "The limited data we have from Israel [on a second booster] demonstrates that these people make better antibodies for a period of time … But it's not clear how long those antibodies will last and how much more effective it is than people who did not get the [second] booster."

Boosters became a high priority for Long Islanders this winter as COVID-19 positivity rates surged to 27% amid the spread of the omicron variant. Positivity rates on the Island have since receded to below 5%.

More should get boosters

Although more than 80% of all New Yorkers have received at least one dose of the vaccine, only 45% have returned for a booster, despite data showing that the additional shot provides 90% protection against hospitalization, according to the CDC.

Dr. Sharon Nachman, chief of pediatric infectious diseases at Stony Brook Medicine, said she would like to see booster rates increase significantly before focusing on a second round of shots.

"Before we get to the fourth dose, it's going to be critical to bring the population up to getting their third or booster dose," she said.

In October, the CDC approved a third primary shot of the vaccine for immunocompromised individuals — including those in chemotherapy, with HIV or with organ transplants who take medication to suppress the immune system — that would be delivered at least 28 days after the second shot.

Three months after that third shot, these individuals would be eligible for their second booster, or fourth shot of the Pfizer or Moderna vaccine. The CDC encourages people with weakened immune systems who originally received the Johnson & Johnson vaccine to take two additional shots, instead of one.

Last month, Israel recommended a fourth shot for individuals 18 and older who were at least five months removed from their third dose. Several European nations also are considering a second booster.

White House Chief Medical Adviser Dr. Anthony Fauci said additional analysis was needed.

"We may need to boost again," Fauci told ABC News last month. "That's entirely conceivable."

Mikael Dolsten, Pfizer's chief scientific officer, told CBS News last month: "It is very likely that we will need a fourth booster, possibly already this spring, particularly if omicron continues to dominate."

Fewer hospitalizations, deaths

Dr. Aaron Glatt, chair of the Department of Medicine at Mount Sinai South Nassau hospital in Oceanside, said several factors could determine the need for a second booster, including whether cases spike back up, if a new, more potent, variant emerges and if drugmakers produce an omicron-specific vaccine, as they are now studying.

Although omicron has proved to be more contagious than previous variants, it's caused fewer hospitalizations and deaths nationwide, particularly among those fully vaccinated and boosted.

A decision on a second booster may "depend on what variant comes out or if you have natural immunity" from contracting the virus, Glatt said. " … But right now it's just too soon to know."

Farber said policymakers must first decide what the booster's goal should be before greenlighting another round.

"A lot of it will come down to what is the goal of the vaccination at that point of time," he said. "Is it to prevent hospitalization and people from dying and being sick or is to prevent COVID? And those are two separate questions that need to be answered because I'm not sure we're going to be giving boosters every six months to people to prevent mild COVID that doesn't cause a clinical illness much worse than a cold."

There is no precedent in modern medicine for administering a vaccine more than once a year, health professionals said. The flu shot is given annually.

With omicron creating fewer serious illnesses than the delta variant, it's difficult to predict if federal regulators will see the need for a second round of boosters so quickly, Nachman said.

"The question is: what is the harm," she said. "Is it on the side of giving the booster or is the harm on the side of having someone not adequately protected when they are at high risk of severe or moderate disease? That's why more information is needed."

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By Robert Brodsky

robert.brodsky@newsday.com@BrodskyRobert

Robert Brodsky is a breaking news reporter who has worked at Newsday since 2011. He is a Queens College and American University alum.