In my previous post, I suggested that while we’re pursuing Phase 3 testing of several promising Covid-19 vaccines, we could simultaneously offer those same, unapproved vaccines to a wider community of volunteers, as long as those volunteers were fully informed. The benefits of moving quickly, I argued, would outweigh the risks.
[Editor’s note: Steven Salzberg is a Bloomberg Distinguished Professor of Biomedical Engineering, Computer Science, and Biostatistics at Johns Hopkins University.]
I was wrong. After reading many of the responses to my article, some of them outlining the risks in greater detail, I have concluded that (1) the risks are greater than I presented them, and (2) the benefits are not as great as I had thought.
On point (1), there are several risks that I didn’t emphasize sufficiently. One is that although phase 1 and 2 trials establish safety, they don’t tell the whole story. Phase 3 also looks at safety, and because many more subjects are involved, Phase 3 can identify less-common side effects that might still be very bad. (One example is ADE, which can make a viral illness worse than it would otherwise be.) These less-common side effects are a big risk of moving too quickly.
Another risk is that of trust: as many people pointed out on Twitter, if we expand the distribution of vaccines too quickly, and then the vaccine doesn’t work, we may seriously undermine the public’s trust in any eventual vaccine that really does work. That in turn will reduce the number of people willing to be vaccinated, which could cause serious harm to public health.
One thing I’ve learned as a scientist is that if you get something wrong, you need to admit it, learn from the experience, and move on. I was wrong.