AstraZeneca CEO questions mRNA vaccine superiority, raising theory that his company's shot offers longer-lasting protection

Pascal Soriot
The heightened T-cell immunity afforded by the AstraZeneca vaccine works more effectively on those who contract the virus, CEO Pascal Soriot told the BBC on Tuesday. (AstraZeneca)

AstraZeneca’s chief executive Pascal Soriot is challenging the notion that his company's vaccine is inferior to the mRNA vaccines from Moderna and Pfizer.

In fact, he’s claiming that differing hospitalization rates between the U.K. and the rest of Europe suggest that the AZ vaccine may provide longer-lasting protection against severe disease in the elderly than the blockbuster mRNA shots.

Still, Soriot admitted that there was no data to support his claim.

In speaking to BBC, Soriot said Tuesday that the heightened T-cell immunity afforded by the AZ vaccine may last longer than the antibody protection offered by the mRNA vaccines.

“Everybody’s focused on antibodies but you see them decline over time," Soriot told BBC 4 Radio, as quoted by the Guardian. "What remains very important is the T-cell response. As soon as the virus attacks you, they wake up and they come to the rescue and they defend you. But it takes them a little while.”

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Soriot points to the anecdotal example of the U.K., where uptake of the vaccine was high among the elderly in the initial months of the rollout. Soriot says this explains why the hospitalization rate has remained low in the U.K., while the infection rate remains high.

This effect is not evident through the rest of Europe, Soriot claims, largely because much of the continent shunned the vaccine after Germany recommended against providing it to those 65 and older in January, citing lower efficacy. Several other European countries followed suit, though they have since reversed their decisions as more reliable long-term data has emerged,

“I’m not saying there was any mistake done by anybody,” Soriot told the BBC. “I’m just saying that there’s a lot of data that still need to be made available that we don’t have.”  

Europe’s relationship with the AZ vaccine has been checkered. In addition to the confusion over its efficacy in the elderly, there were concerns over rare and severe blood clots, which convinced many countries to temporarily suspend its use among younger people.  

More drama ensued when AZ ran into manufacturing delays and failed to meet supply pledges, prompting the European Union to sue. The bloc then declined to renew a supply agreement with AZ, opting instead to buy nearly 2 billion doses from Pfizer-BioNTech.

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As AZ tries to drum up future business for its vaccine, expect the company to preach the T-cell mantra.

“What I’m saying is that T-cells do matter and in particular it relates to the durability of the response, especially in older people, and this vaccine has been shown to stimulate T-cells to a higher degree in older people,” Soriot said.

As of last week, more than two billion doses of the vaccine have been delivered globally, AZ said.