Experts say U.S. vaccination efforts aren't likely to be significantly affected after the U.S. Food and Drug Administration (FDA) and U.S. Centers for Disease Control and Prevention (CDC) halted use of Johnson & Johnson's (JNJ) vaccine Tuesday due to concerns of a rare side effect.
The FDA and CDC said in a joint statement that out of more than 6.8 million doses administered of the J&J vaccine, there were six reports, including one fatality, of a rare blood clot in the brain — known as cerebral venous sinus thrombosis.
"All six cases occurred among women between the ages of 18 and 48, and symptoms occurred 6 to 13 days after vaccination," according to the statement.
"We are recommending a pause in the use of this vaccine out of an abundance of caution," the two health agencies added.
New York and New Jersey announced Tuesday they would pause administering the vaccine, as a result, and pharmacies Walgreens (WBA) and CVS (CVS) have said they, too, will heed the advice.
"We are immediately suspending the administration of the J&J vaccine at our stores and off-site clinics and are awaiting further guidance. We are reaching out to patients with scheduled appointments and rescheduling vaccinations from other manufacturers, as supply allows," Walgreens said in a statement.
CVS, while adhering to the pause, is not shifting to a different vaccine.
"Due to this pause, we are emailing all customers who have a scheduled appointment to receive a Johnson & Johnson COVID-19 vaccine at CVS Pharmacy to inform them that their appointment is being cancelled," a spokesperson told Yahoo Finance Tuesday.
Pharmacy sites have been viewed as key to President Joe Biden's target to vaccinate 200 million individuals in the first 100 days. But a pause of the vaccine for a few days to a few weeks, as anticipated by the health agencies, is unlikely to impact U.S. vaccination efforts, officials said Tuesday.
White House COVID-19 Response Team coordinator, Jeff Zients, said in a statement that the vaccine accounts for "less than 5% of the recorded shots in arms in the United States to date."
The recommendation to pause is not a mandate, according to health officials, who said during a media briefing Tuesday that doctors and vaccine administrators can use their own judgement on the risks against the benefits of the vaccine.
Dr. Peter Marks, director of the Center for Biologics Evaluation and Research (CBER) at FDA, said the fact sheet provided to health professionals will be updated to include the information about the blood clots.
Marks and FDA interim director Dr. Janet Woodcock said during a media briefing that the occurrence remains very rare, and a probable cause is yet unknown.
"This is an immune response that occurs very, very rarely after some people receive the vaccine," Marks said.
When asked if, based on the cases involving women aged 18-48 there is a possible link to oral contraceptives, officials said the answer remains unclear.
Dr. Anand Swaminathan, assistant clinical professor of emergency medicine at St. Joseph's Hospital in New Jersey, told Yahoo Finance that it is going to be interesting to see if there is a link, and if so, to simply advise women to pause using the contraceptives for a month to determine the effect.
Woodcock noted the information is "going to be very concerning to Americans" but the agencies will be providing an update in the coming days.
For now, anyone who received the vaccine over a month ago is at low risk, and anyone who received it in recent weeks should remain alert for any symptoms, including severe headaches, abdominal pain, leg pain or shortness of breath, officials said.
Déjà vu
Dr. Paul Offit, director of the Vaccine Education Center at the Children's Hospital of Philadelphia and one of the independent experts on the FDA's vaccine advisory committee, told Yahoo Finance the move by the health agencies to recommend the vaccine's halt is not unexpected after similar reports with AstraZeneca's (AZN) vaccine in Europe.
"Now we're finding, it is a class effect" among the viral vector vaccine platforms, Offit said.
He added that the J&J pause is unlikely to affect the U.S. rollout as both mRNA vaccines comprise a vast majority of the committed doses the country has purchase — 300 million in total from both Moderna (MRNA) and Pfizer (PFE)/ BioNTech (BNTX).
"I don't think we necessarily need to rely on the Johnson & Johnson vaccine," Offit said, adding that between the mRNA options, "We are going to be able to vaccinate all Americans by mid-summer."
It is unclear as of Tuesday if, as in in some European countries, younger women will be excluded among the recommended recipients of the J&J vaccine.
The concerns have prompted questions about other COVID-19 vaccines. In a statement Tuesday, Moderna proactively addressed the issue, noting that there has been no link between the specific blood clots — occurring in the brain— and its vaccine.
In a statement Tuesday, J&J said it was proactively delaying its vaccine rollout in Europe.
"We are aware of an extremely rare disorder involving people with blood clots in combination with low platelets in a small number of individuals who have received our COVID-19 vaccine," the company said, adding, "We have been reviewing these cases with European health authorities."
The CDC will convene its vaccine advisory committee Wednesday to review the cases and "assess their potential significance."
The FDA will further review the reports as well, recommending a pause in the use of the vaccine until the process concludes.
