Pascal Soriot knows how to make a headline. The AstraZeneca PLC chief executive officer gave a rare interview to the BBC to mark the opening of a £1 billion ($1.3 billion) research facility in Cambridge. But he couldn’t resist a little plug for his vaccine, too.
“If you look at the U.K., there was a big peak of infections but not so many hospitalizations relative to Europe,” he said. His suggestion — made in dulcet tones and bracketed with the caveat that more research needs to be done — is that the AstraZeneca vaccine offers more longer-term effectiveness against serious illness than rival jabs produced by Pfizer Inc. and Moderna Inc. In other words, Britain’s home-grown jab is the reason the country is faring better with the latest COVID-19 wave than Europe.
Only it’s not that simple.
AstraZeneca’s vaccine has been shown to provide lower levels of protection against COVID-19 infection than the Pfizer vaccine. Never mind that, Soriot says. Antibodies aren’t the only criteria by which we should judge a vaccine’s worth. “What I’m saying is that T cells do matter,” Soriot said “and this vaccine has been shown to stimulate T cells to a higher degree in older people.”
He’s certainly got a point. Adenovirus vaccines are designed to get a T-cell immune response, which is considered longer lasting than the B cells, which produce antibodies. University of Birmingham clinical lecturer Helen Parry and colleagues tested blood samples from 165 people aged over 80 who received a single dose of either the Pfizer or the AstraZeneca COVID-19 vaccine. While antibody responses to the two vaccines were equal five weeks after being vaccinated with a single dose, they found a more enhanced T-cell response in those who received the AstraZeneca vaccine.
A paper published last week in the New England Journal of Medicine compares the immune responses in the Johnson & Johnson vaccine (also an adenovirus vaccine) and the two mRNA vaccines from Pfizer and Moderna, and found the J&J jab produced a T-cell response that was eight times the mRNA’s.
Beyond that, though, things go fuzzy. The mRNA vaccines also stimulate cellular immunity and it’s not easy to say whether the differentials that have been found would make a real difference in terms of serious illness.
There is a question as to whether T-cell immunity is sufficient to make up for the waning of antibodies. Bloomberg Intelligence pharmaceutical analyst Sam Fazeli reported last week on a study showing that initial antibody levels for Pfizer’s vaccine were nine times higher than AstraZeneca’s.
AstraZeneca’s vaccine effectiveness fell to 47.3% from 62.7% after 20 weeks, compared to 69.7% from 92.4% for Pfizer. Comparisons of hospitalization and deaths among those who have taken AstraZeneca and Pfizer show a bigger drop in protection with the AstraZeneca vaccine from about 15 weeks.
There are many complex explanations for the current wave of infections in both Europe and parts of the U.S. But it is largely a crisis of the unvaccinated. Distrust of federal authority, high levels of vaccine hesitancy in certain regions, among immigrant communities and undocumented migrants, all seem to have played a role.
And while the U.K.’s National Health Service did an excellent job of pulling in people to get vaccinated early on, more fragmented health care delivery systems, or those that depend on people being more proactive, left greater pockets of the unvaccinated where infections could take seed and spread.
How easy it is to forget too that the U.K. had its own worrying surge of infections after the summer. Rates of hospitalization and death were higher than in many European countries. I noted at the time that the situation could soon be reversed as the U.K. booster program picks up and a spate of infections among school children burns out. This pandemic has taught us a lot about the perils of jumping to conclusions.
So why would Soriot float a theory that entails several large logical leaps for which there is little hard evidence? One can only speculate.
The CEO had already presided over a number of commercial successes at AstraZeneca since he took over in 2012, but the collaboration with Oxford University that produced the first approved COVID-19 vaccine, and made it available at no profit in Britain and globally, was a triumph of science, but also of goal-setting and obstacle-clearing. And yet the company’s early missteps created confusion and annoyed regulators. (The FDA still hasn’t approved the AstraZeneca vaccine.) The vaccine nationalism, with AstraZeneca caught in the middle, didn’t help. It’s been a long year, and maybe Soriot was looking for a little more credit.
As likely, he has his eye on what lies ahead. The company is creating a dedicated unit for its vaccines and antibody therapies and has signed a series of for-profit agreements. While the vaccine will continue to be supplied at cost to poorer countries, Soriot says the disease is now becoming endemic and so the company should feel free to earn something on its vaccine as its competitors do. A little horn-blowing probably felt justified and also expedient. And for the fact-checkers listening, Soriot was careful to add, “there’s no proof of anything.”
Asked what he thought about the T-cell theory later on the same radio program, former Health Secretary Jeremy Hunt couldn’t pass judgment. But AstraZeneca, he said, had a lot to be proud of. Soriot, said Hunt, is “a Frenchman who is more proudly British than most Brits.”
Therese Raphael is a columnist for Bloomberg Opinion.