The Third Vaccine, and Vaccine Choice

If the main concern is trying to ensure that you don't suffer from severe disease or risk of death... all three vaccines, while not perfect, seem to be effective. If your concern is around preventing symptomatic disease... the data we have today suggests that the Pfizer and Moderna vaccines are more effective [than Johnson & Johnson's] ... That said, they also seem to have slightly more adverse events associated with them. When I say 'adverse events,' it's fatigue or feeling crummy or pain, etc.

The reality is SARS-CoV-2 is not going away ... [It will] probably be endemic like influenza, like the flu. And we're already seeing efforts by the vaccine producers, like Moderna, that have announced that they are already developing an updated version of the vaccine for new emerging dangerous variants.

In any typical year, flu vaccines probably are anywhere between 40-60% effective. So the fact that we're in the 70s and 80s and 90s [with COVID-19 vaccines], we've already cleared a very high bar—and mind you, we did all of that within one year.

One thing that's really important to think about when you're comparing the Moderna and Pfizer vaccines to the Johnson & Johnson vaccine is that it is very difficult to directly compare their efficacy because the studies were set up to have a different endpoint.