Antibody dependent enhancement (ADE) explained by Biologist Josh Mitteldorf

Vaccines, convalescent plasma, and monoclonal antibodies for covid-19

BMJ 2020; 370 doi: (Published 09 July 2020) Cite this as: BMJ 2020;370:m2722


We know this "vaccine" is a new technology, and we have have every reason to think it has long-term effects on the body's immune system. In the past, we have gauged those long-term effects before licensing vaccines, even when they are not based on new technologies, and we have found some positive long-term effects and some negative long-term effects. In the case of the COVID vaccines, we have rushed them out to hundreds of millions of people without any idea what the long-term effects are. By any standard of medical practice pre-2020, this would be considered irresponsible, dangerous, some would say criminal. Is COVID19 really such a threat that it justifies massive experimentation with human lives at stake?

The COVID virus is usually gone from the patient within a few days. What gets people into the hospital and sometimes kills them is called a cytokine storm. The body is overreacting with inflammation so strong that it can be suicidal. This is how people die of COVID. The virus doesn't kill them directly.

   Fast-forward to the vaccine. Vaccines have the function of prepping the body, ensuring a stronger immune response the next time the pathogen appears. If all goes well, the virus appears, the body is ready for it, and the immune system wipes out the virus quickly, before it can take hold. No further action is needed, and the patient doesn't become sick. But when things go badly, the virus appears and the body reacts TOO strongly, going quickly into cytokine storm mode. The virus can be MORE deadly to people who have had the vaccine. This is called "pathogenic priming", and it is not just a theoretical possibility. It happened repeatedly in ferrets during testing of earlier coronavirus vaccines, and that's why we haven't had coronavirus vaccines until this last year.

   The current crop of vaccines have been confirmed to provoke an immune response in humans. The question is, how often will the response be appropriate, and how often will it be in the regime of pathogenic priming? In other words, how many people will avoid the disease because they have been vaccinated, and how many will have a MORE SEVERE CASE because they've been vaccinated? The abbreviated vaccine trials were not designed to answer this question, but there are now millions of people who have been vaccinated, and it will be important to watch them and see.

- Josh