They’re known as the Johnson & Johnson 16 million.

That is the number of Americans who received the one-shot vaccine as their first COVID-19 dose and are now in the gray zone. While health officials encourage those who have received the double-dose Pfizer-BioNTech or Moderna series to receive a third shot, J&J recipients are only eligible for their original shot and a single booster.

According to the Centers for Disease Control and Prevention, approximately 3.5 million of the 16.3 million people who received the J&J vaccine as their first dose have been boosted. But they can’t go any further.

“I suspect there are thousands of J&J recipients like me who are questioning our safety,” said Donna Alston, 61, of Philadelphia. “Last week, I went to my pharmacy to see if I could sign up, and they said no.” I’m not allowed to get any more vaccines unless the CDC gives me specific instructions.”

On February 27, the Food and Drug Administration approved the J&J vaccine. The agency didn’t allow a booster dose of the vaccine for adults 18 and older until Oct. 20, at least two months after their initial dose. A third dose has not been approved.

This is due in part to the fact that so few J&J doses have been administered compared to the 190 million people who have been fully vaccinated with a two-dose series of either Pfizer or Moderna.

That’s a significant data gap, according to Dr. Kelly Moore, CEO of, which educates health care professionals about U.S. vaccine recommendations.

“The mRNA vaccines went into widespread use at least three months earlier and established a far larger market share,” Moore said, adding that US regulators must make decisions based on evidence, not assumptions, which takes time to gather.

He told reporters on a conference call Monday that there was strong evidence that an adenovirus vector vaccine, such as J&J’s, followed by an mRNA vaccine produced a very good immune response. The agency is now assessing how long that response will last. He anticipates receiving information within the next few weeks to months.

“As we collect data, we’ll analyze it and potentially make recommendations,” Marks explained. Until data showed that the vaccine’s protection could fade over time. Then there was the ultra-infectious omicron variant, and suddenly two shots weren’t enough. She’d like another boost right now.

The J&J vaccine’s coverage does wane over time, according to Dr. William Schaffner, an infectious disease expert at Vanderbilt University Medical Center. However, the level of protection it provides against severe illness and death remains high, according to him.

“I can understand some of those people feeling a little forlorn and at a disadvantage as a result of all the talk about three shots,” he said. “I’d just comfort them and tell them that J&J followed by one of the mRNAs elicits a massive antibody response.”

Emily Moore, 50, of Denver, received a booster dose of Pfizer vaccine in addition to her original J&J. She’s a diabetic, and she’d like a third now, but she’s been turned down by her pharmacy, which is awaiting further booster guidance.

Even for those willing to skirt the truth, it appears that sneaking extra doses is becoming more difficult than it was previously. Oliver said she had several friends in Boulder who got J&J as their first shot and then went in for a second without mentioning their first.

For the time being, J&J recipients are playing a waiting game in the hopes of receiving another immune system boost.