The data
By these measures, all five vaccines – from Pfizer, Moderna, AstraZeneca, Novavax and Johnson & Johnson – look extremely good. Of the roughly 75,000 people who received any of the five in a research trial, not one died from Covid, and only a few people appear to have been hospitalized. None of them remained hospitalized 28 days after receiving an injection.
To put this in perspective, it’s helpful to reflect on what Covid has done so far to a representative group of 75,000 American adults: it has killed around 150 and sent several hundred more to hospital. . Vaccines reduce those numbers to zero and almost zero, based on research trials.
Zero is not even the most relevant reference. A typical influenza season in the United States kills between 5 and 15 in 75,000 adults and hospitalizes more than 100.
I guess you would agree that any vaccine that turns Covid into something much milder than a typical flu deserves to be called effective. But that’s not the scientific definition. When you read that the Johnson & Johnson vaccine was 66% effective or the Novavax vaccine was 89% effective, those numbers refer to the prevention of all diseases. They view the mild symptoms as failure.
“When it comes to serious outcomes, which is what we really care about, the news is fantastic,” said Dr. Aaron Richterman, infectious disease specialist at the University of Pennsylvania.
The variants
What about the highly contagious new virus variants that have emerged in Britain, Brazil and South Africa? The South African variant appears to make vaccines less effective at clearing infections.
Fortunately, there is no indication yet that this increases the number of deaths among those vaccinated. Two of the five vaccines – from Johnson & Johnson and Novavax – reported results from South Africa, and none of the people who received a vaccine died from Covid. “People are still not seriously ill. They still don’t die, ”Dr. Rebecca Wurtz of the University of Minnesota School of Public Health told me.