As Chicago prepares to expand its vaccine eligibility, with hopes that additional supply becomes available, questions linger over the potential for additional vaccines.
Chicago Department of Public Health Commissioner addressed questions surrounding the potential for future vaccines in the U.S., including the AstraZeneca vaccine currently at the center of some scrutiny in Europe.
"AstraZeneca has been in the news a lot these last few days, related to decisions that were made, especially in Europe," Arwady said during a Facebook Live Tuesday. "They're wanting to look at some more safety related to the potential of blood clots. Wasn't seen in the trials, there's some follow up related to it."
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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."
Germany, France and Italy on Monday became the latest 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.
Arwady noted that there were early concerns the vaccine may not offer as much protection against the South African strain,
"AstraZeneca is also the vaccine that South Africa had decided not to move ahead with because they had seen some less protection related to the variant that first emerged in South Africa," Arwady said. "So I'd say it's a vaccine that in European settings is getting a lot of extra scrutiny, and certainly, you know, there have been the trials have been happening here in the U.S., like related to what does COVID look like here, what are the exposures like."
She added 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. I 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 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."
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.
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.