Pause in Johnson & Johnson shots raises fears of new vaccine hesitancy

A decision by the Food and Drug Administration (FDA) and the Centers for Disease Control and Prevention (CDC) to pause administration of a coronavirus vaccine developed by Johnson & Johnson is raising concerns among public health experts that it will impede vaccine acceptance across the country.

In a statement Tuesday morning, top scientists at the FDA and CDC cited six cases of cerebral venous sinus thrombosis, developed in women between the ages of 18 and 48 years old between six and 13 days after they received the Johnson & Johnson vaccine.  

The CDC will convene its Advisory Committee on Immunization Practices on Wednesday to review the facts of the cases, and FDA will conduct its own review. But in the meantime, the two agencies recommended hitting the brakes on the shot “out of an abundance of caution.”

The decision is the second major setback for coronavirus vaccines that use an adenovirus structure to teach a body’s immune system to recognize and combat the SARS-CoV-2 virus that causes COVID-19.

It follows pauses of another adenovirus-based vaccine, developed by AstraZeneca and Oxford University, in the European Union and many of its member states. 

The European Union’s top drug regulator said last week it was looking into potential clots in four people who had received the Johnson & Johnson vaccine, clots similar to those in a few dozen people who received the AstraZeneca shot.

The Johnson & Johnson vaccine is one of three approved for emergency use in the United States, along with others from Moderna and Pfizer-BioNTech. Those two vaccines use a different technology, known as messenger RNA, and no serious side effects have been described in the tens of millions of Americans who have received those shots.

States that had planned to inoculate people using the Johnson & Johnson shot scrambled Tuesday to make alternate plans. New York Health Commissioner Howard Zucker said in a statement that those who had an appointment Tuesday to receive the Johnson & Johnson shot would instead get a Pfizer vaccine.

But the U.S. will soon run out of people who are willing to receive any coronavirus vaccine, as hesitancy over the inoculation remains stubbornly high among minority populations and among conservative Americans who still voice skepticism.

Any additional excuses for skepticism of the vaccine, experts worry, will lengthen the pandemic just as the end draws near.

“A global pause of the J&J vaccine seems excessive given the popular mythologies that are likely to arise from this statement for all vaccines,” said Prabhjot Singh, a physician and global health expert at the Icahn School of Medicine at Mount Sinai.

“That said, we are not privy to the deliberations about narrower restrictions considered by the FDA and CDC, or J&Js own corporate concerns for product safety and liability. I do trust that a range of options were thoroughly reviewed.”

The six adverse cases occurred among more than 6.8 million people who have received the vaccine in the United States so far — a rate of just 0.0000009 adverse cases per 100 doses administered.

The tiny rate of adverse reactions is still a sign that the Johnson & Johnson product is safe and effective across a broad swath of the general public, though experts said the caution and concern was warranted.

“I believe the Johnson & Johnson vaccine is exceedingly safe. These are very rare events,” Ashish Jha, dean of the Brown University School of Public Health, said Tuesday on Good Morning America. “But we don’t know if they’re linked to the vaccine and we don’t know if there are other cases we’ve missed. So it’s the right thing.”

Tuesday’s decision is the second major setback for Johnson & Johnson, which had been one of the first companies in the world to begin developing a coronavirus vaccine in March of last year. Last month, a subcontractor manufacturing the vaccine acknowledged it had spoiled 15 million doses on a production line in Baltimore.

Public health experts have been worried about the number of Americans who have expressed skepticism over the vaccines developed in the year since the coronavirus began spreading across the world. That hesitancy has declined in recent months as millions of Americans have received shots with no serious adverse reactions.  

A survey conducted by the Kaiser Family Foundation in late March showed 37 percent of Americans said they would not get a vaccine, would get one only if required or would wait and see before deciding whether to get a vaccine. That figure was down from 51 percent in January and 44 percent in March.

Republican voters and white evangelical Christians are most likely to say they will definitely not get the coronavirus vaccine. Younger Americans and Black adults were most likely to say they would wait and see whether to get a vaccine. 

“I anticipate this announcement is going to increase vaccine hesitancy beyond J&J. It underscores the importance of direct conversations with folks by trusted messengers about their fears, concerns and options to be safe amidst a pandemic. We still have a ways to go before all communities are in the clear,” he said. 

Public health experts have been deliberately evolving their strategies to assuage fears or concerns over the vaccines. They have begun to stress that the technology underlying both the mRNA and adenovirus vaccines has been in development and, in the case of the adenovirus-vectored vaccines, in use for decades. And they have stressed vaccine acceptance rates among doctors, which is far higher than the general public, as a way to build trust.

But the fallout is likely to have implications beyond American borders, especially because global public health officials expected the Johnson & Johnson and AstraZeneca vaccines to contribute substantially to vaccination efforts in the world’s poorest countries.

Peter Hotez, a leading coronavirus vaccinologist and dean of Baylor University’s National School of Tropical Medicine, said he worried that the pause would reverberate in low- and middle-income countries that were in line to use the adenovirus-based vaccines, which are easier to store and administer than the mRNA-based vaccines.

“In the U.S., we have other vaccine options,” Hotez said in an email. “I’m worried about the impact for [low- and middle-income countries] given that adenovirus-vectored vaccines … were supposed to be workhorses.”

Updated 12:43 p.m.