To Speed Vaccine Development, Infect Me With the Coronavirus
This week, I joined a rapidly growing group of 14,183 people via the organization 1 Day Sooner in volunteering for human challenge trials (HCTs) to test promising vaccines against the novel coronavirus. If selected, I would be administered a candidate vaccine or a placebo vaccine then deliberately exposed to the SARS-CoV-2 coronavirus.
I did not sign up for this endeavor seeking heroism or notoriety, but because I weighed my own personal risks against the benefits to global society. In this calculation, there is an overwhelming net benefit. As a white, healthy, physically active 32-year-old with no underlying health conditions, my risk of death from COVID-19 could be as high as 1 in 1,200, but more likely as low as .014 percent, roughly 1 in 7,400. Participants in HCTs would be given small, controlled doses of virus and quarantined with excellent medical care, so that rate could be even lower. Still, we can estimate that if 20,000 people took part in HCTs, between two and seventeen participants could die.
In the absence of HCTs, thousands of participants would be given experimental vaccines or placebos in phase III trials then asked to go about their lives so they can potentially be exposed to the novel coronavirus. These trials last many months to ensure adequate infection numbers and sample sizes to ascertain efficacy. HCTs could attain more accurate results in a fraction of the time. Roughly 5,000 people are currently dying every day from COVID-19. That number could swell this winter in the event of a predicted second wave. If three months could be shaved off the estimated 12 to 18 months needed to produce an effective vaccine, hundreds of thousands of lives could be saved. Millions more could safely return to livelihoods, visit quarantined loved ones (particularly the elderly), and resume abandoned pastimes that much sooner.
There is presently a debate over whether or not human challenge trials for COVID-19 should be permitted. That debate will grow more pressing as phase I and II trials – meant to gauge safety and preliminary efficacy – for some of the dozens of vaccine candidates near completion this summer. The two main arguments against HCTs are ethical and practical. Ethically, given that we still know comparatively little about SARS-CoV-2, can there truly be informed consent for trial volunteers?
Practically, HCTs may not cut enough time off the vaccine development process to make them worthwhile. Before an HCT can be carried out, a study must be conducted to determine a proper dose of virus to administer to trial participants. This, too, involves volunteers and can itself take four to ten weeks to complete. Moreover, Moderna, the leading U.S. company producing a vaccine, estimates that they can have a phase III trial up and running by early summer, with vaccine approval (if the data looks good) as early as the first quarter of 2021. Oxford University's timeline for their vaccine candidate is even more optimistic: a phase III trial starting in late May with approval by September. Tal Zaks, the chief medical officer of Moderna, is skeptical that HCTs will be necessary.
There's no guarantee that Moderna and Oxford's rosy forecasts will come to fruition, however. In the past, HCTs have been successfully deployed against dengue fever, typhoid fever, malaria, cholera, and influenza, so there is historical precedent for present action. As one of the thousands of HCT volunteers, I write now to say that we understand and accept the risks, and, if called upon, are ready to do our part to rid humanity of the infectious scourge of COVID-19.