“The CDC and the FDA are taking these concerns about blood clots and the J&J vaccine seriously and are diligently gathering the data,” the official said.
An expert outside the government familiar with the situation admitted that health officials were taking the issue seriously.
“The CDC is very concerned and they are working very hard on this and are monitoring this closely,” said the expert, who spoke on condition of anonymity due to the sensitive nature of the matter.
The concern in the United States is not just about the Johnson & Johnson shooting per se. At a time when U.S. health officials are urging Americans to get vaccinated as soon as they can, there are concerns that media coverage of the clots studied in connection with Johnson & Johnson’s vaccine may make some Americans more hesitant to get vaccinated against Covid-19.
Vaccine reluctance is already a problem in the United States, and officials from the United States Centers for Disease Control and Prevention and the United States Food and Drug Administration “are considering how to communicate about the problem without giving the impression that something is wrong with the [Johnson & Johnson] vaccine, ”said the federal health official.
Another expert familiar with the situation said it was the right approach, stressing the importance of communicating without scaring people.
“I hope the HHS is having a discussion about this right now,” the expert said, referring to the US Department of Health and Human Services.
In a statement, Johnson & Johnson said its tracking of side effects revealed “a small number of very rare events after vaccination. To date, no clear causal relationship has been established between these rare events and the [Johnson & Johson] Vaccine against covid19. ”
The FDA issued a statement last week that it was aware of reports of “serious thromboembolic events” in the United States occurring “in a few people after receiving the drug. [Johnson & Johnson] COVID-19 vaccines ”and that“ for the moment, we have not found a cause and effect relationship with the vaccination ”.
J&J study participant’s illness revealed
What the FDA scientists pointed out, however, is that in the trial, about the same number of people were given a placebo – a dose of saline that does nothing – as the vaccine. However, when comparing the two groups, more study participants developed clots after receiving the vaccine than the placebo.
Calling it a “slight numerical imbalance,” the FDA noted that there were 15 events in 14 participants who received the vaccine, compared to 10 events in 10 participants who received the placebo.
The FDA report concluded that given this imbalance, “the vaccine cannot be ruled out as a contributing factor” and that the FDA would recommend “monitoring” for blood clots once the vaccine is deployed.
Against this backdrop, Andy Slavitt, White House senior advisor on Covid-19, told a press briefing on Monday that the United States is still on track to meet its Covid-19 vaccination goals even without additional doses of Johnson & Johnson.
Examining blood clots
This is not the first time that blood clots have appeared in connection with a Covid-19 vaccine.
The AstraZeneca vaccine, which has not been authorized in the United States, has been authorized in more than 70 countries. The J&J vaccine and the AstraZeneca vaccines are similar – they both use adenovirus vectors to make them work.
In March, doctors in several European countries had started noticing “very rare” cases of unusual blood clots in people who received the AstraZeneca vaccine.
The agency noted that its safety committee reviewed 62 cases of cerebral venous sinus thrombosis and 24 cases of splanchnic vein thrombosis, a type of blood clot in the abdomen, including 18 fatalities. The cases were reported at a time when 25 million people in Europe and the UK had received the vaccine.
The European agency concluded that unusual blood clots with low blood platelet counts should be listed as ‘very rare side effects’ of the AstraZeneca vaccine. While advising the public to look for signs of clots, regulators said the benefits of the shot were always worth the risk.
The European Union cleared the J&J vaccine last month, and it is expected to be rolled out there in the coming weeks.
A ‘vaccine-induced’ condition
Hematologists say it’s not the first time they’ve seen unusual blood clots with low platelet counts. Sometimes people who are given a very common blood thinner called heparin can develop the disease.
But the people who received the AstraZeneca vaccine and developed the clots had not taken heparin.
“It’s actually very interesting,” said Dr. Peter Kouides, past president of the Thrombosis and Hemostasis Societies of North America. “The risk is very, very low, but it appears to be a real vaccine-triggered disorder.”
He said there are treatments for this “very serious disease”, but they don’t always work.
“When you have [this] happen, all bets are off, “said Dr Hanny Al-Samkari, hematologist and instructor at Harvard Medical School.” You can get clots anywhere. You can have them in your brain, in your belly, in your extremities, in your heart – it doesn’t matter. They can occur just about anywhere and this is obviously often problematic and / or fatal. ”
Harsh words for Johnson & Johnson
Part of J&J’s statement angered a prominent FDA vaccine adviser, as it appeared to say that Pfizer and Moderna’s vaccines also raised similar safety concerns – which it said he stated, is just not true.
“We are aware that thromboembolic events, including those with thrombocytopenia, have been reported with all COVID-19 vaccines,” according to the Johnson & Johnson statement.
Given that this is such a large number, it is no surprise that some members of this group suffer from thrombocytopenia, a condition characterized by low levels of platelets in the blood, said committee member Dr Paul Offit. FDA Advisory on Vaccines and Related Biologics. The question, he said, is whether this number of people has exceeded what one would expect if they had not been vaccinated.
“It’s a really irresponsible thing to say,” Offit said, referring to J&J’s statement. “It will frighten people unnecessarily about Moderna and Pfizer when not only is there no evidence that it is a problem – there is evidence that there is no problem,” Offit added. .
A spokesperson for J&J declined to comment on Offit’s criticisms.
CNN’s Lauren Mascarenhas, Michelle Watson and Jacqueline Howard contributed to this report.