On the latest episode of the Social Distance podcast, James Hamblin and Katherine Wells ask the infectious-disease expert Stephen Thomas to explain the medical and ethical issues involved in developing a new vaccine.
Listen to the episode here:
What follows is an edited and condensed transcript of their conversation.
Katherine Wells: I don’t actually understand how vaccines are developed on any sort of granular level.
James Hamblin: How do you go from this tiny prototype in eight people where they didn’t seem to be harmed, to a billion people with a needle in their arm? It is a technical process that could go a few different ways, depending on our capacity or willingness to incur risk. We can play it really safe and do it really slow, but lots of people are dying every day of this disease. There are incentives right now to take risks that usually vaccine-development people wouldn’t take.
An idea that is being discussed in vaccine circles is “human challenge trials,” which we’ve done for some other viruses, but they are not being done right now for this coronavirus. They involve giving people one of these test vaccines and then purposefully exposing them, in a standardized way, to the virus. When you have a disease like this, you have to get a huge number of people with the test vaccine and then see what percentage gets sick and what percentage doesn’t. But [with a regular trial] you don’t really know who is actually exposed [to the virus]. How many of those people who didn’t get sick just didn’t get sick because they were staying at home with their huge bag of Purell?