AstraZeneca released new data on its U.S. trial Monday as the company prepares to submit its findings to the U.S. Food and Drug Administration for emergency use authorization.
The findings of a large U.S. trial showed that the coronavirus vaccine developed by AstraZeneca and the University of Oxford is 79% effective in preventing symptomatic illness and 100% effective against severe disease and hospitalization, according to CNBC. The analysis, published Monday, came from data on 32,449 participants at 88 trial centers in the U.S., Peru and Chile.
AstraZeneca reportedly plans to submit its U.S. trial analysis to the FDA for emergency use authorization in the coming weeks.
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AstraZeneca has been eyeing a spring approval in the U.S. for its COVID vaccine, even as the shot sits at the center of concerns in Europe, with countries divided over how to handle the rollout.
Germany, France and Italy were among the recent countries to suspend use of AstraZeneca’s COVID-19 vaccine over reports of dangerous blood clots in some recipients, though the company and European regulators have said there is no evidence the shot is to blame.
AstraZeneca said on its website that there have been 37 reports of blood clots out of more than 17 million people vaccinated in the 27-country European Union and Britain. The drugmaker said there is no evidence the vaccine carries an increased risk of clots.
In fact, it said the incidence of clots is much lower than would be expected to occur naturally in a general population of this size and is similar to that of other licensed COVID-19 vaccines.
The European Medicines Agency and the World Health Organization have also said that the data does not suggest the vaccine caused the clots and that people should continue to be immunized.
The European Medicines Agency said "there is currently no indication that vaccination has caused these conditions, which are not listed as side effects with this vaccine."
"The position of EMA’s safety committee PRAC is that the vaccine’s benefits continue to outweigh its risks and the vaccine can continue to be administered while investigation of cases of thromboembolic events is ongoing," the agency stated.
Denmark was the first to temporarily halt use of the AstraZeneca vaccine Thursday after reports of blood clots in some people. Norway, Iceland and Bulgaria followed suit and suspended use of the vaccine.
Thailand and Congo have also delayed use of the vaccine, pending an investigation, while Italy and Romania stopped using shots from one particular batch. Austria has also halted use of doses from a single, but different, batch.
France, Poland and Nigeria, meanwhile, said they would continue using the AstraZeneca shot even as national regulators investigate.
The blood clots aren't the only concern to arise with the AstraZeneca vaccine, however.
Chicago's top doctor said earlier this month that the COVID-19 vaccine developed by AstraZeneca and the University of Oxford "has performed well broadly," but there were concerns it may not be as effective against the coronavirus variant that emerged in South Africa.
"There's been some extra attention sort of looking at looking at the vaccine in that context, but it has generally also been a very good vaccine," Arwady said.
Concerns over vaccine effectiveness with newer variants of the virus, particularly the South African variant, have also been raised with other vaccines.
The variant from South Africa, for example, reduced Pfizer-BioNTech's antibody protection by two-thirds, according to CNBC, citing a February study. Meanwhile, Moderna's neutralizing antibodies dropped six-fold, according to the report.
Arwady has said the vaccine could appear before the U.S. Food and Drug Administration sometime in April.
"The FDA, the CDC, as you know, everybody would be looking really at the details of that. I would really, really like to get another vaccine available," Arwady said. "Certainly getting a lot of people vaccinated here is good. If any of this is substantiated, related to that there's actually a significantly increased risk of bleeding or there's other safety concerns, the FDA would not approve this vaccine, like just to be clear on that. But if that's not something that's seen in any of the studies, and if the efficacy continues to look good against the strains that we're seeing broadly here in the U.S., I would certainly welcome another vaccine."
Arwady, along with other medical experts, have noted that no link between the vaccine and blood clots has so far been identified.
"I want to be really clear that, based on everything I've seen, there's not been a clear link at this point related to blood clots and AstraZeneca" Arwady said. "But there have been, you know, decisions made by some countries to sort of put that that particular vaccine on hold, or to not offer it at this time if they've got another vaccine available while they're looking into that some more."
To compare each of the three coronavirus vaccines currently available to Illinois residents, click here.
The AstraZeneca shot has become a key tool in European countries’ efforts to vaccinate their citizens against COVID-19. But Pfizer's and Moderna's vaccines are also used on the continent, and Johnson & Johnson's one-shot vaccine has been authorized but not yet delivered.
In the U.S., which relies on the Pfizer and Moderna vaccines, AstraZeneca is expected to apply any day now for authorization.