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.
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.