Antibodies created during a first-time infection could, under very specific circumstances, end up enhancing the disease rather than protecting against subsequent infections. Researchers called this “antibody-dependent enhancement,” or ADE.
…
For SARS-CoV-2, it’s unclear if any forms of immune enhancement could play a role in infections or vaccines under development, but there is no evidence so far. “[It’s just] a theoretical risk, but people are being extremely careful to make sure that this risk is not becoming a reality,” notes [immunologist] Paul-Henri Lambert.
…
“With COVID-19, we have a disease which in eighty percent of people is selectively mild. So what you would not like is to give a vaccine that would not protect well and in a certain percentage of people make the disease worse,” [Lambert said.]
…
As long as it’s a good vaccine with a specific target that induces a strong neutralizing antibody response, it’s unlikely we’ll see ADE, “certainly not commonly,” [immunologist James] Crowe says. “It’s only when you have an ineffective vaccine or antibody that you might see [ADE]. And no one wants to move those [candidates] forward anyway, so that’s why I’m optimistic.”
