Editor in Chief of this news organization Eric Topol, MD, founder and director of the Scripps Research Translational Institute in La Jolla, Calif., and professor of molecular medicine, has been closely following COVID-19 data since the pandemic began. He spoke with writer Miriam E. Tucker about the latest on SARS-CoV-2 variants and their impact on vaccine efficacy. The conversation serves as a follow-up to his April 13, 2021, New York Times opinion piece, in which he advised readers that “all variants are innocent until proven guilty.”
You have expressed overall confidence in the efficacy of the vaccines thus far despite the emergence of variants, with some caveats. How do you see the current situation?
The Centers for Disease Control and Prevention has designated five “variants of concern,” but only three of them are real concerns – B.1.1.7, first detected in the United Kingdom; P.1, in Brazil and Japan; and B.1.351, in South Africa. Yet, all three are susceptible to our current vaccines.
The U.K. B.1.1.7 is the worst variant of all because it’s hypertransmissible, so I call it a “superspreader strain.” It also causes more severe illness independent of the spread, so it’s a double whammy. It’s clear that it also causes more deaths. The only arguable point is whether it’s 30% or 50% more deaths, but regardless, it’s more lethal and more transmissible.
The B.1.1.7 is going to be the dominant strain worldwide. It could develop new mutations within it that could come back to haunt us. We must keep watch.
But for now, it’s fully responsive to all the vaccines, which is great because if we didn’t have them, we wouldn’t have gotten through this U.S. pandemic like we have, and neither would Israel and the United Kingdom and other countries that have been able to get out of the crisis. We met the enemy and put it in check.
As for the South Africa variant of concern, B.1.351, we just got some encouraging news showing that it›s very responsive to the Pfizer/BioNTech mRNA vaccine in large numbers of people. The study was conducted in Qatar following that country’s mass immunization campaign in which a total of 385,853 people had received at least one vaccine dose and 265,410 had completed the two doses as of March 31, 2021.
At 2 weeks past the second dose, the vaccine was 75% effective at preventing any documented infection with the B.1.351 variant and 89.5% effective against B.1.1.7. The vaccine’s effectiveness against severe, critical, or fatal COVID-19 was greater than 97.4% for all circulating strains in Qatar, where B.1.1.7 and B.1.351 are most prominent.
We also know that B.1.351 is very responsive to the Johnson & Johnson vaccine and the Novavax [vaccine in development] to a lesser degree. It is the most immune-evading variant we’ve seen thus far, with the highest likelihood of providing some vaccine resistance, yet not enough to interfere with vaccination campaigns. So that’s great news.
The caveats here are that you definitely need two doses of the mRNA vaccines to combat the B.1.351 variant. Also, the AstraZeneca vaccine failed to prevent it in South Africa. However, that study was hard to judge because it was underpowered for number of people with mild infections. So, it didn’t look as if it had any efficacy, but maybe it would if tested in a real trial.
The P.1 (Brazil) variant is the second-highest concern after B.1.1.7 because it’s the only one in the United States that’s still headed up. It seems to be competing a bit with B.1.1.7 here. We know it was associated with the crisis in Brazil, in Chile, and some other South American countries. It has some immune escape, but not as bad as B.1.351. It also appears to have somewhat greater transmissibility but not as much as B.1.1.7.
With P.1, we just don’t know enough yet. It was difficult to assess in Brazil because they were in the midst of a catastrophe – like India is now – and you don’t know how much of it is dragged by the catastrophe vs driving it.
We have to respond to P.1 carefully. There are some good data that it does respond to the Chinese vaccine Sinovac and the AstraZeneca vaccine, and it appears to respond to the others as well, based on serum studies. So it doesn’t look like vaccines will be the worry with this variant. Rather, it could be competing with B.1.1.7 and could lead to breakthrough infections in vaccinated people or reinfections in unvaccinated people who had COVID-19. We need several more weeks to sort it out.
Although the B.1.427 and B.1.429 variants initially seen in California remain on the CDC’s concern list, I’m not worried about them.