One of the recurring arguments about the coronavirus vaccines is that they’re being “undersold” — that public discussion of them is emphasizing caution too much and inadvertently fueling vaccine skepticism. As the New York Times wrote a few weeks ago:
. . . the 95 percent number understates the effectiveness, because it counts anyone who came down with a mild case of Covid-19 as a failure. But turning Covid into a typical flu — as the vaccines evidently did for most of the remaining 5 percent — is actually a success. Of the 32,000 people who received the Moderna or Pfizer vaccine in a research trial, do you want to guess how many contracted a severe Covid case? One.
The decision by the South African government to halt the use of the AstraZeneca vaccine because of its perceived ineffectiveness against the local variant appears to continue this trend. Yes, it would be preferable if the AstraZeneca vaccine, which doesn’t have the refrigeration issues that the Pfizer and Moderna vaccines have, worked as effectively.
In the aftermath of the South African government’s decision, you’re seeing headlines like, “shots fail against new variant.” Except the study didn’t prove that the vaccine fails against the South African variant. The study showed that the vaccine didn’t do much to stop mild and moderate infections in a small sample of mostly young people . . . which is not really the biggest problem facing the world from this pandemic:
The number of cases evaluated as part of the studies outlined by South African scientists on Sunday were low, making it difficult to pinpoint just how effective or not the vaccine might be against the variant.
And because the clinical trial participants who were evaluated were relatively young and unlikely to become severely ill, it was impossible for the scientists to determine if the variant interfered with the AstraZeneca-Oxford vaccine’s ability to protect against severe Covid-19, hospitalizations or deaths.
The scientists said, however, that they believed the vaccine might protect against more severe cases, based on the immune responses detected in blood samples from people who were given it. If further studies show that to be the case, South African health officials will consider resuming use of the AstraZeneca-Oxford vaccine, they said.
You know what we laymen would call a novel virus that only caused flu-like symptoms? The flu. If we could wave a magic wand and turn SARS-CoV-2 into a virus that could only cause mild or moderate infection, we would be dancing in the streets. We can deal with mild or moderate infection that doesn’t require hospitalization. Every year, lots of people catch the flu, miss some days of work or school, drink lots of fluids, run a fever, and fully recover. (A lot fewer this year.) What we really want to avoid are mass hospitalizations and elderly and immunocompromised people dying from the virus.
Now, if the AstraZeneca vaccine doesn’t work at all to stop hospitalization and death among older and immunocompromised people, then the decision to halt its use makes perfect sense. It would be a bit surprising, though, as previous trials — including one in South Africa — found it prevented hospitalization and death.