I remain skeptical of the chances for a vaccine against SARS-CoV-2 this year. I was skeptical when we would “have a vaccine by September” and little has happened to change that.

The New England Journal of Medicine has been publishing a number of well-reasoned, scientifically-based reports on vaccine development, and it is probably a good source to follow. However, they published an odd editorial on why we should trust the safety of a new SARS-CoV-2 vaccine (in case you have lost track of the alphabet soup, “SARS-CoV-2” is the name of the virus, “COVID-19” is the name of the disease caused by the virus). The article falls into three parts.

The first part reassures us by citing the historical safety of vaccines in the US—and that safety record is impressive. The author attributes much of the impressive safety numbers to our system of doing extended “Phase-III” trials before releasing vaccines.

The third part of the editorial explains why a future SARS-CoV-2 vaccine would likely be safe, and again credits the power of strong Phase-III trials for assuring our safety.

It’s the middle part of the article, which seems oddly disconnected from the first and third parts, that’s disturbing. It points out that the Phase-III process for SARS-CoV-2 vaccines has been subverted with unprecedented shortcuts. So in the end, the piece reads:

  • Historically, vaccines in the US have been incredibly safe because of our rigorous Phase-III testing procedures!
  • We’re abandoning our rigorous Phase-III testing procedures for SARS-CoV-2 vaccines.
  • SARS-CoV-2 vaccines will be safe because of our rigorous Phase-III testing procedures!

It left me with a strong sense of the surreal.

Another short NEJM piece did leave me with a real sense of hope. If you’ll recall from my explainer on zoonotic infections, viruses that move to human hosts are sometimes quite deadly at first, but drift toward less virulence over time. We just don’t know how long that time is. Well, researchers have now identified a number of genetic variants of SARS-CoV-2 that are less virulent than the wild type virus. Even back in January–March 2020, 22% of study patients (in Singapore) had a variant that was far less virulent. Folks who got that variant were significantly less likely to develop hypoxia (which is what leads to ICU admission, ventilator support, and death). Less virulent strains are already out there, they’re in a large proportion of the infected population, and, for the reasons I’ve already given (mostly that they don’t kill their hosts), will likely overwhelm the wild-type virus in the coming months.

Still, this is not the time to grow complacent! We’re just seeing the beginnings of this. Keep wearing your masks. Stay home whenever you can. Wash your hands and keep them off your face. Stay safe!