FDA, CDC advisers say expect many questions about AstraZeneca Covid-19 vaccine

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Lots of questions.

In interviews with CNN, several vaccine advisors in the US government did not question whether the AstraZeneca vaccine would eventually obtain emergency FDA approval. However, they said the company’s application is likely to bring problems that did not arise when the three Covid-19 vaccines currently used in the United States – manufactured by Pfizer, Moderna and Johnson & Johnson – were considered for their own emergency use authorizations.

“Clearly, more questions have been raised about the AstraZeneca vaccine than any of the other vaccines that are now licensed in the United States,” said Dr. Arnold Monto, chairman of the FDA’s Advisory Committee on Vaccines and Biologicals. related, which analyzes the vaccine applications and advises the FDA on their authorization.

These advisers – who work at academic medical centers and not the government – said reports of blood clots after vaccination, which led more than a dozen Western European countries to suspend the use of the AstraZeneca vaccine, were not the only problem. Questions were also raised about other aspects of AstraZeneca efficacy and safety data.

“It feels different and it felt different even before the blood clots appeared,” said Dr. William Schaffner, a liaison member of the CDC’s Advisory Committee on Immunization Practices.

AstraZeneca is expected to ask the FDA to authorize its Covid-19 vaccine for emergency use in March or early April, sources with knowledge of the company’s ongoing clinical trial told Reuters.

Monto, Schaffner and other government advisers said they look forward to receiving the “dossier” of data on the safety and efficacy of a vaccine that the FDA publicly releases when a pharmaceutical company applies for emergency use authorization.

“I will bring an open mind to these deliberations,” said Dr. Ofer Levy, a member of the FDA’s vaccine advisory committee.

“I’m going where the data leads me,” said another member, Dr. H. Cody Meissner.

As more and more European countries have suspended the launch of the AstraZeneca vaccine, the company, as well as international health agencies, have defended the vaccine.

“Everyone’s safety is our first priority,” according to an AstraZeneca statement sent to CNN on Wednesday. “About 17 million people in the EU and the UK have now received our vaccine, and the number of blood clots reported in this group is less than the hundreds of cases that would be expected among the general population.”

The World Health Organization, UK health authorities and the European Medicines Agency have expressed support for the AstraZeneca vaccine, saying its benefits outweigh any risks.

Despite this support, several US government advisers have said they are worried that after months of hearing questions about the AstraZeneca vaccine, many Americans may perceive it as problematic and do not want to take it.

“It’s hard to ring the bell,” said Dr. Paul Offit, a member of the FDA’s advisory committee. “Once people get scared, it’s hard to disregard them.”

New report on blood clots

According to an EMA statement issued on Thursday, ” [AstraZeneca] the vaccine is not associated with an increased risk of general blood clots. ”

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The statement said that about 20 million people in the UK and the European Union, as well as Iceland, Liechtenstein and Norway, had received the AstraZeneca vaccine since March 16 and certain specific types of rare platelet-related clotting problems were reported. of blood.

The number of reports of those rare clotting problems “exceeds expectations and causation, although not confirmed, cannot be ruled out”, according to the statement, which states that the vaccine label will be updated to include more information about these events.

One type of clot is mesenteric venous thrombosis, which is a clot in one or more of the major veins that drains blood from the intestines. Another is cerebral venous sinus thrombosis, where a clot forms in the brain’s drainage system. A third is disseminated intravascular coagulation, which is blood clots in several blood vessels.

The EMA said that since March 16, it has looked at seven cases of disseminated intravascular coagulation and 18 cases of cerebral venous sinus thrombosis.

“One mistake after another”

The AstraZeneca vaccine, which was developed in partnership with Oxford University, began with a reputation for being one of the most promising Covid-19 vaccines in the world.

South Africa halts launch of AstraZeneca vaccine after study shows less protection against variants
Last spring and summer, Oxford researchers spoke of this as top-ranked, although later they would sometimes back down and warn against the over-promising.

Dr. Adrian Hill, one of Oxford’s leading scientists, has sometimes insulted even other vaccine manufacturers, for example by calling Modern’a Covid-19 vaccine technology “strange” and “unproven.”

But it is fast advancing a year and AstraZeneca is facing challenges. He twice put his clinical trials on hold when participants who received the vaccine became ill – twice he was restarted when it was determined that the diseases were not related to the vaccine.
Then, in November, questions arose about the company’s efficacy data and it was revealed that a mistake had been made in the study and some participants received the wrong dose. Oxford then told CNN that a “difference in the manufacturing process” had led to error.
“We’ve done a lot of vaccine clinical trials in the last two decades, and that’s never happened,” said Meissner, a member of the FDA’s vaccine advisory committee. “I read in their Lancet how they explained it, but it was a little torturous.”

Menelas Pangalos, executive vice president of biopharmaceutical research and development at AstraZeneca, told the Wall Street Journal in November that “the mistake was in fact irrelevant” and that the vaccine “meets the approval threshold with a vaccine more than 60% effective.”

Then, last month, South Africa stopped launching the AstraZeneca vaccine after a study showed that it offered less protection against the coronavirus variant that was first identified there. The study, published later in the New England Journal of Medicine, found that the AstraZeneca vaccine “did not show protection against mild to moderate Covid-19” due to the variant.
Biden administration finalizes plans to send millions of doses of AstraZeneca vaccine to Canada and Mexico

Currently, more than a dozen European countries have suspended the use of the vaccine due to concerns about blood clots.

“It’s so ironic – last summer there were these usually quite reluctant British donuts beating their drums – ‘We’ll be the first, we’ll be the best’ – and this is the vaccine that had one glitch after another,” he said. Schaffner.

An AstraZeneca spokesman told CNN in a January Lancet study that found the vaccine had “an acceptable safety profile and was shown to be effective against symptomatic COVID-19.”

An AstraZeneca press release said on Sunday that out of 17 million people who received the vaccine in the European Union and the UK, there were 15 events of deep vein thrombosis and 22 events of pulmonary embolism, based on information received by the company in March. 8.

“This is much lower than would be expected to occur naturally in a general population of this size,” according to the company, which added that there is no evidence of an increased risk of pulmonary embolism, venous thrombosis. (DVT) or thrombocytopenia, in any age group, gender, group or country. ”

The statement did not mention the rare types of coagulation events discussed on Thursday by European regulators.

Agreements for 300 million doses of AstraZeneca

AstraZeneca already has agreements with the US government to deliver 300 million doses, according to prepared remarks sent to Congress by the company last month.

While government advisers said more vaccine is better, they say it is unclear what role AstraZeneca would play if its vaccine is authorized.

There will be more than enough vaccine from Pfizer, Moderna and Johnson & Johnson to vaccinate every American adult by the end of May, White House coordinator Covid Jeff Zients said earlier this month.

Government advisers with whom CNN spoke said that if the AstraZeneca vaccine is distributed in the United States, they worry that Americans may perceive it as inferior to the three that are already distributed.

“I’m very worried that there will be a lot of people who will say ‘thank you very much but not’ AstraZeneca because of this publicity,” said Schaffner, a CDC adviser.

He said that if there is not enough demand for it, the US could donate part of its AstraZeneca offering to developing countries, where it would be particularly useful because it is easier to transport and store than Pfizer or Moderna vaccines. .

The Biden administration has already announced plans to ship several million doses of AstraZeneca to other countries.

“I can confirm that we have 7 million available doses of AstraZeneca available,” White House Press Secretary Jen Psaki said at Thursday’s White House news conference. “2.5 million of them are working to complete the loan plans for Mexico and 1.5 million for Canada.”

“We could be like Solomon and cut the baby in half and say we contracted to buy these doses and use a third of them and give the rest of the developing countries and do a little vaccine diplomacy,” A said Schaffner. – That’s a possibility.

Ryan Prior, Samira Said, Michael Nedelman and Casey Hicks contributed to this report.

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