Is the Delta variant the result of antibody dependent enhancement?

What is Antibody Dependent Enhancement (ADE)?

Antibodies bind to pathogens, like the virus that causes COVID; that’s how antibodies stop viruses from making you sick. However, very rarely, antibodies can do the opposite and help pathogens make you ill. This is known as “antibody dependent enhancement”. The classic example of this is Dengue Fever. Infection with one type of Dengue virus produces antibodies which can make you even sicker if you get infected with another type of Dengue.

Is the Delta variant the result of antibody dependent enhancement?

There is no evidence of antibody dependent enhancement in COVID-19, including infection by the Delta variant. Antibody dependent enhancement can cause more severe symptoms, but it does not result in the development of new variants. The Delta variant was caused by a change in the virus itself. 

How do we monitor for antibody dependent enhancement due to vaccines?

The large COVID vaccine clinical trials were designed to identify adverse events, including rare events, like antibody dependent enhancement. If there is any evidence of antibody dependent enhancement during clinical trials, the vaccines are not approved and are not used.

Do the COVID-19 vaccines cause ADE?

There is also no evidence of antibody dependent enhancement in people vaccinated against COVID-19 in animal studies or human clinical trials. Additionally, now we have hundreds of millions of people around the world who were vaccinated and then exposed to the Delta variant with no increase in severe symptoms or disease. In fact, the opposite is true: vaccinated people are less likely to be infected with the Delta variant and less likely to develop severe symptoms, be hospitalized, or die of COVID-19. 

Last update: December 17, 2021   11:00am EST

Science review: GSN