Data gap threatens to complicate Johnson & Johnson vaccine pause

Yet that effort has not lessened the immense pressure on the Biden administration to find a way forward — quickly. The administration has for months worked to reduce vaccine hesitancy nationwide and any prolonged pause in use of the Johnson & Johnson shot could undermine that effort. Frustration is also growing among governors who say the J&J vaccine — the only one-shot option available in the U.S. — is crucial for inoculating vulnerable groups like the people experiencing homelessness, homebound seniors and prisoners.

“The longer the pause is, the longer it’s going to take for us to convince people that this particular vaccine is safe again,” Arkansas Gov. Asa Hutchinson, a Republican, told POLITICO.

Already, conspiracy theorists and anti-vaccine proponents are using the Johnson & Johnson setback to fuel hesitancy and mistrust through social media.

“It’s a setback — no question about it,” said Peter Hotez, a vaccine expert at Baylor College of Medicine. “When you have this kind of anti-vaccine aggression out there, it changes the equation. This will be exploited.”

The White House did not respond to a request for comment. HHS did not comment on the record for this story.

Federal officials have said they called for a pause, rather than just issuing a warning to the public and clinicians, because of unusual aspects of the clots now under investigation. Known as cerebral venous sinus thromboses, they develop in blood vessels leading to the brain. Several of the women who developed the condition after vaccination also had low levels of platelets, which help form clots. Health experts believe the strange pairing could be the byproduct of an immune reaction to the vaccine.

The fact that the pairing can be worsened by the blood thinner heparin was of particular concern to Biden administration officials, because the drug is a standard treatment for most types of blood clots.

The six known cases were reported to J&J directly or to the CDC through its Vaccine Adverse Event Reporting System (VAERS), which relies on health care providers to flag when an individual experiences a reaction to any vaccine.

Federal officials are now urging doctors to report any cases that have so far flown under their radar to guide both the CDC vaccine advisory panel’s recommendations and a separate but parallel probe by the FDA, which authorized the J&J vaccine in March.