When Will a Johnson & Johnson Booster Shot Be Available?

Earlier this week, the Food and Drug Administration officially gave the green light for recipients of the Pfizer-BioNTech or Moderna COVID-19 vaccines to get booster shots roughly eight months post-second dose. Now, odds are the nearly 14 million Americans who received the single-shot Johnson & Johnson vaccine are wondering when they, too, can expect news about COVID booster shots. (

And while, so far, there's no official timeline as for when a Johnson & Johnson booster shot will be available, it seems quite likely that it'll be authorized by health officials soon. On Wednesday, U.S. Surgeon General, Vivek Murthy, M.D., confirmed that officials "expect" boosters for the J & J vaccine will be needed in the future and that more information on the potential shot should be just around the corner.

"For those who got the J&J vaccine: We do expect that boosters will be needed in the future and we are expecting more data in the coming weeks that will help us make recommendations for people who got J&J," tweeted Dr. Murthy.

Why Isn't There a J & J Booster Shot Yet?

There are a few key factors as to why Pfizer and Moderna have been authorized for boosters while Johnson & Johnson is still waiting in the wings, according to Vivek Cherian, M.D., an internal medicine physician affiliated with the University of Maryland Medical System. "First of all, the J & J vaccine clinical trials started after [in late September] those for Pfizer and Moderna," says Dr. Cherian. Moderna and Pfizer had, respectively, already published the results of their initial trials in July and August. Thus, "the J & J vaccine was authorized later than the Moderna and Pfizer vaccines. Because of this, there have been far fewer doses of the J&J vaccine administered in this country, and the Centers for Disease Control and Prevention is waiting for more data/studies that would allow for a second dose recommendation," he explains. (

Additionally, the Johnson & Johnson vaccinations were temporarily paused in the U.S. while health officials investigated reports of a rare blood clotting condition that occurred in some individuals after receiving the one-dose vaccine. The vaccine faced another setback in April 2021 when roughly 60 million J & J doses had to be discarded after an ingredient mix-up at a manufacturing plant. Combined, these delays and issues can help to explain why more than 150 million Americans have gotten Pfizer or Moderna, compared to the roughly 14 million who've received the single-dose Johnson & Johnson, according to the CDC.

It's also important to note that the Johnson & Johnson vaccine works differently than its double-dose counterparts. As mRNA vaccines, the Pfizer and Moderna shots work by encoding a part of the spike protein (the part of the virus that attaches to cells in your body) found on the surface of the SARS-CoV-2 virus (the virus that causes COVID-19). The two vaccines use those encoded pieces from SARs-CoV-2 to prompt an immune response from your body and develop antibodies to ultimately protect against the virus, infectious disease expert Amesh A. Adalja, M.D., senior scholar at the Johns Hopkins Center for Health Security, previously told Shape.

Johnson & Johnson on the other hand is an adenovector vaccine, as Brittany Busse, M.D., associate medical director at WorkCare previously told Shape. That means it uses an inactivated virus (adenovirus, known to cause symptoms of the common cold) as a vector to deliver those spike proteins from the SARS-CoV-2. Your body will recognize these proteins as a threat and create antibodies, protecting you against the virus as well. (FYI: The flu shot works similarly.)

Will the Booster Be Another Johnson & Johnson Shot?

If the end goal of all three vaccines is to develop antibodies for protection, then why can't you just mix and match shots? "Research is currently ongoing for boosting with a different vaccine," says Dr. Cherian. "My guess is ultimately individuals who got the J & J vaccine will be approved to get boosted with an mRNA vaccine. Other countries have actually already started advising individuals to go ahead with this strategy," he notes, sharing that Germany, Canada, and Thailand have already authorized a "mix-and-match" approach.

Though the waiting period might feel frustrating, heeding the guidance of health officials and waiting for approval to get your booster — whether it's Johnson & Johnson or otherwise — is the best course of action. "Our J & J patients have not been overlooked or neglected. It's just the way the data are coming in," as William Schaffner, M.D., professor in the Division of Infectious Diseases at Vanderbilt University Medical Center, told CNN. "You can't make good recommendations without the data." (

Bottom Line On a J & J Booster Shot

No matter where you are in your vaccine process, you can feel confident knowing that all three vaccines are "highly effective at protecting against the worst outcomes of COVID-19," says Dr. Cherian. "Meaning if you are fully vaccinated, you are well protected against severe disease and hospitalization." And when the time comes to snag a booster, doing so will seemingly only further your protection level. "Preliminary trials/data have suggested that individuals boosted with an mRNA vaccine are not only safe but also have elicited a stronger immune response, and you can be sure the CDC is monitoring this data as it comes in on a daily basis," he explains.

Johnson & Johnson hive, this counts for you as well. "You can be reassured that if you've received the J & J vaccine you are very well protected, including from the Delta variant," says Dr. Cherian. "Regardless of which vaccine you've already received, you can continue protecting yourself by wearing masks indoors and continuing to exercise caution."

The information in this story is accurate as of press time. As updates about coronavirus COVID-19 continue to evolve, it's possible that some information and recommendations in this story have changed since initial publication. We encourage you to check in regularly with resources such as the CDC, the WHO, and your local public health department for the most up-to-date data and recommendations.