Thursday, May 14, 2020

A human-challenge study for a COVID-19 vaccine is a challenge

This news took me aback somewhat. There are people out there - lots of people, indeed, to the tune of over 16,000 (now 20,000, last I checked) - who have expressed a willingess, nay, an enthusiasm, to be deliberately infected with the COVID-19 virus in order to act as guinea pigs for a potential vaccine.
Welcome to the 1 Day Sooner campaign, a project that grew out of a scholarly article by a groups of bioethicists and epidemiologists in the Journal of Infectious Diseases in mid-April. The signees to the 1 Day Sooner registry are mainly young, idealistic people and, yes, young people are somewhat less likely to catch the virus, less likely to suffer the more extreme symptoms, and less likely to die. But they are not immune from the virus, and a serious illness or even death IS a risk. But the potential benefits of cutting down the time needed to test a vaccine by many months or even years in this way can be measured in terms of THOUSANDS of potential lives saved.
This kind of "human-challenge study" could cut down the numbers of test subjects needed to as little as 100, rather than many thousands, because researchers can be assured of ALL 100 catching the disease, which would be deliberately administered by nasal drop. Then, rather than waiting several months in the "hope" that test subjects will catch the virus out in the community, results would be in in a matter of a few weeks.
It's an extraordinary idea, and it blows me away that so many young people are willing to run such high risks for the greater good. But it's a medical ethicist's nightmare. The benefits are huge, but the risks are very real, and COVID-19 has already proven itself to be an unpredictable and highly dangerous adversary. However, with four-and-a-half million cases and over three hundred thousand deaths (and counting), some scientists are starting to think that a riskier-than-normal approach may be justified. And some argue that the risks can be minimized, or at least managed, leaving the resulting risk profile within the bounds of what we already routinely approve.  The World Health Organization is already giving the idea serious consideration (although it would also require sign-off by a national health authority, such as the Food and Drug Administration in the USA, and probably a whole lot of legal work).
Apprently, the idea is not new - arguably, it goes all the way back to Edward Jenner and the very first vaccine in the 18th century, and more recently it has been used for vaccines for malaria, flu, dengue, cholera and typhoid - but it is new to me. And COVID-19 presents some unique challenges that were not present in those other human-challenge studies, not least the fact that there are currently absolutely NO treatments available. And, because the novel coronavirus is so unpredictable and still so little understood, it is difficult to give volunteers an accurate sense of the risks involved, a sine qua non of any vaccine test. But, hey, what if we could get a vaccine within weeks?
It did occur to me to wonder whether we couldn't use those anti-lockdown protesters (the first of whom are already starting to show up in infection spikes) as vaccine test subjects. They don't seem to mind mixing and mingling with all and sundry. But then I realized: most of them are probably anti-vaxxers too...

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