Why purposely infect people with COVID-19?

Even as much focus has been on vaccination rollout and progress of COVID-19 variants, some researchers are undertaking a study to understand aspects of the virus’ activity. The concept, according to U.K. researchers, is to infect up to 90 people with the SARS-CoV-19 virus in a research setting, determine the minimal amount of virus necessary to infect someone, then monitor the progression of the infection in real-time. It is hoped that early aspects of COVID-19 disease in humans can be better monitored by this approach rather than by simply examining individuals who have had natural infections.

One problem with this concept is that the the amount of virus needed to infect is likely to be different in every individual. This is due to variations in size, nasal anatomy, and immunity. Therefore, to really understand the early kinetics and human immune response in COVID-19 illness you would have to infect a large number of people to get generalized immune response data. This is well beyond the “dozens” of persons the investigators propose.

The investigators also plan to only infect young, healthy people, ages 19-30, who will presumably only develop mild or most likely asymptomatic illness. This does not tell us anything about older individuals or those with pre-existing conditions — the groups most likely to develop severe illness from COVID-19 and most important to understand.

Early screening for virus could allow studies like the investigators propose without purposeful infection

Paradoxically, we are now identifying people early in the COVID-19 illness cycle due to increased, asymptomatic screening. Using SARS-CoV-2 virus PCR and antigen testing we can identify individuals within days of infection. Therefore, it is unlikely that infecting a young, healthy individual under observation will actually yield information that cannot be achieved with intensive monitoring of people who were accidentally infected.

While there is possibly some value in characterizing immune protection from COVID-19 vaccines by purposeful infecting immunized individuals, this is something the investigators will do only later in their work. Also, given the differences in immunity in humans and the fact they are not examining vulnerable individuals, it seems hard to believe they will get more information on vaccine immunity than has been obtained in the clinical trials of over 100,000 individuals that have already been conducted.

I worry that given the extensive publicity around this announcement this proposal is more of a stunt than a worthwhile investigation.

Published by jbakerjrblog

Immunologist, former Army MD, former head of allergy and clinical immunology at University of Michigan, vaccine developer and opinionated guy.

7 thoughts on “Why purposely infect people with COVID-19?

  1. This is interesting. I suppose that while I can understand why they would take this approach, it also seems to be a bit reckless. As you say, it’s likely that inter-individual variation in the amount of virus it takes to produce an infection is a serious confounding variable; I don’t know how one would sort out the factors involved in that and whether it is worth the risk.

    Still, we know for certain that once a person develops COVID-19, men are much more likely to die from COVID-19 than are women. This is true across all racial, ethnic and age groups, hence, I would be interested to know if men are more likely to be infected as well given that men have more ACE-2 binding sites than do women. This could help elucidate the mechanism involved with infection as well.


      1. You make a great point re. the sampling population, and you’re correct: population-based studies where one could try to develop a matched-pair data set with a large enough N to provide decent statistical power for the analyses would be a much better way to control for potential confounding variables, etc. Plus, the very questionable ethics involved in the study design that you and Dr. Fogarty raise are a no-brainer vis-a-vis spiking this study.

        Liked by 1 person

  2. I question the ethics of this study. Infecting a person with an infection for which there is no therapy and which has the potential for serious illness, death and long term sequelae is unethical. The study director said tht the fact that the participants were being paid justified the experiment. It is shameful that any physician would take part in this study.
    Your comments on the questionable design of the study make it even more reprehensible (if that is possible).
    William M. Fogarty, Jr., MD, MACP

    Liked by 1 person

    1. Paying them is inherently coercive. Absurd justification. There is this conundrum to their entire goal; if they use young people who can be safely challenged then they won’t get ill from the infection so they cannot study the illness.


  3. I am somewhat amazed that educated researchers could possibly propose and even begin such a harebrained proposal for all the reasons mentioned above. This would have received an intense loud negative response if proposed here in the US. It would be interesting for you to summarize some of the reactions to this proposal in Great Britain.

    Liked by 1 person

    1. Reactions have been mixed but the UK has circled the wagons and drunk the Kool-Aid on COVID. I saw an article that many people are waiting to get vaccinated until they can get the “British” vaccine (AstraZeneca instead of Pfizer)!


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