Too few irons in the fire or out of the frying pan?

By Rob Verkerk PhD; founder, executive & scientific director, ANH-Intl

Associate Professor of Health Sciences Adam MacNeil at Brock University, Canada and his PhD student Jeremia Coish were among the earliest to warn, last June, of the dangers of not looking very carefully at the possibility that vaccines might trigger antibody-dependent enhancement (ADE) of disease. This could mean that people who are vaccinated might, paradoxically, suffer more severe disease when exposed to the wild virus than if they hadn’t been vaccinated

In their aptly titled article, “Out of the frying pan and into the fire? Due diligence warranted for ADE in COVID-19,” published in the journal Microbes and Infection in June 2020, they argue that ADE is well known to be a risk for coronavirus-mediated infections, as well as dengue. For those not already familiar with ADE, it is the paradoxical immune response that makes a person who was previously exposed to the disease, or a vaccine targeting it, more – not less – susceptible in the event that they’re subsequently infected.

Proceed with caution

Seemingly countering this view, in August 2020, was viral epidemiologist Leah Katzelnick PhD, a dengue and zika specialist now in the employ of the National Institute for Allergy and Infectious Diseases (NIAID) headed by Dr Tony Fauci. Along with co-author Scott Halstead, Dr Katzelnick argued that ADE shouldn’t be something to be feared. Katzelnick and Halstead proposed that the fundamental differences between SARS-CoV-2 infection that can cause covid-19 and other diseases, for which ADE has been shown, meant that ADE would be highly unlikely. They supported their arguments with evidence from cases of classic, intrinsic ADE, notably infectious peritonitis (FIP), a coronavirus infection in cats, as well as from respiratory syncytial virus (RSV), dengue and SARS – suggesting significant differences in the pathology, epidemiology and immune responses involved in these diseases as compared with covid and SARS-CoV-2 infection.