Johnson & Johnson's COVID shot could return by late this week with some extra safety warnings: Fauci

Fauci
One safety recommendation being considered for J&J's COVID-19 vaccine? Not treating patients who have clotting symptoms with the popular blood thinner heparin, the FDA says. (NIAID)

Less than a week after U.S. officials halted Johnson & Johnson's COVID-19 vaccine rollout, they're now poised to recommend that vaccinations resume, potentially with new guidance or restrictions, NIAID chief Anthony Fauci said over the weekend.

The U.S. should know by Friday when Johnson & Johnson's COVID-19 vaccine will be back on the menu—though it could come with new restrictions or safety warnings, Fauci, who also serves as chief medical advisor to the president, told CNN's Dana Bash on Sunday. 

The news comes after the CDC and FDA called for a halt to J&J's vaccine rollout last week, citing an "abundance of caution" amid a safety probe into rare blood clots after vaccinations.

Of the more than 7 million people who'd received the shot since its authorization in late February, six recipients—all women between the ages of 18 and 48—were diagnosed with rare blood clots afterward, according to the FDA. 

"I don't want to get ahead of the CDC and the FDA and the advisory committee, but I would imagine that what we will say is: that it would come back and it would come back in some sort of either warning or restriction," Fauci told Bash. 

The CDC's Advisory Committee on Immunization Practices will meet Friday to discuss recommendations for the vaccine. The committee also met last week but didn't reach any conclusions.

Johnson & Johnson, for its part, did not immediately reply to Fierce Pharma's request for comment. 

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Fauci supported the pause last week, drawing links between J&J's side effects and the clotting concerns that have plagued AstraZeneca's vaccine in Europe. 

Those reports "went beyond just women," Fauci noted on CNN. "[T]here's some with some men involved. There was also a great display of the ages."

After a safety probe that started in mid-March, the European Medicines Agency earlier this month recommended that unusual blood clots with low blood platelets should be listed as a “very rare” side effect of AstraZeneca's COVID-19 vaccine. 

AstraZeneca said it would join forces with regulators to update its label, adding that it was “working to understand the individual cases, epidemiology and possible mechanisms that could explain these extremely rare events.”

As with AstraZeneca's shot, health experts have stressed that the J&J side effects are rare—and that both vaccines will remain crucial in the fight to end the pandemic.

Likely accompanying a potential return to the market for J&J's vaccine will be treatment guidelines for doctors that come across the rare clots, experts told Reuters. After the pause, doctors may have a better sense of what to look out for, and which meds to tap for treatment.

"We should say: ‘Listen the side effects are rare, but there is a potential for you to get them and these are what you should look out for... We are talking about headaches, abdominal pain, confusion," Rishi Mehta, an associate medical director at Keck Hospital at the University of Southern California in Los Angeles, told the publication. 

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For example, the FDA has cautioned against using the popular blood thinner heparin in patients who show clotting symptoms after getting the J&J vaccine. Giving heparin to those patients could "make matters worse," Fauci told the news service.

Meanwhile, J&J recently contacted pandemic rivals including AstraZeneca, Pfizer and Moderna to unite on the investigation of clotting side effects, The Wall Street Journal first reported. The alliance's goal would have been to communicate the vaccines' benefits and risks and quell fears among the public. Unfortunately for J&J, at least two of those drugmakers—Moderna and Pfizer—rebuffed the offer, according to WSJ.