CDC says Moderna and Pfizer COVID-19 vaccines are preferred over Johnson & Johnson. What it means for you.

An advisory panel to the Centers for Disease Control and Prevention expressed their preference for Pfizer-BioNTech and Moderna’s mRNA COVID-19 vaccines over Johnson & Johnson’s jab.

Members of the Advisory Committee on Immunization Practices said they were persuaded by new data showing that while blood clots linked to J&J’s vaccine remain very rare, they’re still occurring, and not just in younger women as originally thought.

The CDC quickly endorsed the panel’s recommendation Thursday and released a statement saying the updated guidance followed similar recommendations from other countries, including Canada and the U.K.

J&J said in a statement it's confident the benefits of its vaccine outweigh the risks, and it remains an “important choice” for Americans who can’t or won’t return for multiple vaccinations.

“The safety and well-being of those who use the Johnson & Johnson vaccine continues to be our No. 1 priority,” said Dr. Mathai Mammen, global head of Janssen Research & Developing at J&J. “We appreciate (Thursday’s) discussion and look forward to working with the CDC on next steps.”

Latest news on the Johnson & Johnson vaccine

Until now, the U.S. has treated all three COVID-19 vaccines available to Americans as an equal choice, since large studies found they all offered strong protection and early supplies were limited.

J&J's vaccine initially was welcomed as a single-dose option that could be especially important for hard-to-reach groups who might not get the needed second dose of the Pfizer or Moderna options.

However, people who received the single-dose vaccine were then encouraged by health officials to receive a second dose of the J&J vaccine at least two months after their initial dose to bring their protection up to the same level as those who received two-dose vaccines.

Now, the CDC prefers Americans over the age of 18 get an mRNA booster, as studies showed those vaccines provide more protection against COVID-19 and more cases of blood clots were reported in people who got the J&J vaccine. 

Out of approximately 17 million people in the United States who have gotten the J&J vaccine, there have been 54 cases of the condition called thrombosis with thrombocytopenia and nine deaths.

"This is not a failure of our system, this is actually a success of the very rigorous vaccine safety monitoring and evaluation we have in the U.S.," said Dr. Bill Moss, executive director of the International Vaccine Access Center at the Johns Hopkins Coronavirus Resource Center. "This is really our safety system at work." 

Among those who died from the condition after receiving the J&J vaccine, the median age was 45. There were seven women and two men, all non-Hispanic whites. Seven were obese, three had hypertension and two had diabetes. Two of the patients had no known medical condition.

The cases of TTS have been reported in a wide range of individuals 18 years and older. The highest reporting rate was among women ages 30 to 49, where it was one case per 100,000 doses administered. Overall, 15% of TTS cases have been fatal, the Food and Drug Administration said.

What is thrombosis with thrombocytopenia?

Thrombosis with thrombocytopenia, also known as vaccine-induced thrombatic thrombocytopenia, is the combination of a blood clot with low platelet count. The blood clots form in unusual places, such as veins that drain blood from the brain.

Studies have shown the risks of developing a blood clot from COVID-19 is still far greater than from the vaccines, and the benefits of getting vaccinated continue to outweigh the risks.

How long after getting the J&J vaccine can blood clots occur?

This condition can occur four to 42 days after vaccination.

Symptoms may include a severe headache, visual changes, abdominal pain, nausea and vomiting, back pain, shortness of breath, leg pain or swelling, the appearance of round brown-purple spots, easy bruising, or bleeding, according to the American Society of Hematology.

Is the CDC pulling the COVID vaccine?

No, the CDC has not made any recommendations to pull J&J’s COVID-19 vaccine or any of the vaccines FDA has authorized or approved in the U.S.

The CDC reiterates that getting any vaccine is better than being unvaccinated, and says individuals unable or unwilling to receive an mRNA vaccine will continue to have access to J&J’s vaccine.

The FDA has showed no signs of withdrawing the vaccine from the market or issuing a recall, but they have done this with vaccines before, said Jodie Guest, professor and vice chair of the department of epidemiology at Emory University’s Rollins School of Public Health.

Americans should take comfort knowing the agency is poised to do this if data indicates the vaccine is doing more harm than good, she said.

“There’s an entire regulatory board that reviews the data constantly looking for early warning signals,” Guest said. “The encouraging part for everyone to know is that because that can happen, if it’s needed, it would happen. … But that’s not where we are with Johnson & Johnson.”

What does the CDC recommendation mean? How does it impact boosters?

The CDC’s announcement is a response to the compiling data that show Moderna and Pfizer’s mRNA COVID-19 vaccines are more effective and safer than the J&J vaccine, Guest said.

“We’re still in the middle of an active pandemic and we’re still constantly learning,” she said. “Every time we learn more about how to better protect people and move forward in this pandemic, we owe it to everyone to talk about it.”

As per CDC recommendations, health experts advise J&J vaccine recipients to get a booster of the Moderna or Pfizer-BioNTech vaccine.

This doesn’t mean starting over the vaccination series and getting two doses of an mRNA vaccine, Guests said. Data from mixing-and-matching trials show one dose of an mRNA vaccine produces a robust immune response in someone who’s been vaccinated with J&J.

For proactive folks who have already gotten two doses of the J&J vaccine, health experts advise against getting a third shot of mRNA booster. But these recommendations may change as more data becomes available.

Experts urge those who are still unvaccinated to start their two-dose series of either Pfizer or Moderna’s COVID-19 vaccine. If an mRNA vaccine isn’t immediately available, they recommend getting vaccinated with J&J now and get boosted with an mRNA vaccine later.

“The J&J vaccine is still preferred to no vaccine,” Guest said.

How will this impact underserved communities?

One of the vaccine’s benefits was that it didn’t require follow-up for a second shot, Guest said, which helped people in vulnerable communities with inconsistent or little access to health care get fully vaccinated.

But that's changed with the emergence of highly transmissible variants and boosters, she said.

“We are very specifically going back to all the locations where we did vaccinations with the one dose J&J to make sure that everyone is boosted,” she said.

As Guest returned to these communities with more vaccines in hand, she found people were more receptive to the boosters than they were to the first doses. By visiting them often, her team had built a trusting relationship.

“That’s my entire goal by continually going back,” she said. “Every single conversation you have is a step forward. That’s time well-spent, that’s trust being earned and it shows commitment.”

Contributing: Elizabeth Weise and Karen Weintraub, USA TODAY; Associated Press. Follow Adrianna Rodriguez on Twitter: @AdriannaUSAT. 

Health and patient safety coverage at USA TODAY is made possible in part by a grant from the Masimo Foundation for Ethics, Innovation and Competition in Healthcare. The Masimo Foundation does not provide editorial input.