I'm sure most of you are familiar with ADE by now since it was one of the main problems pointed out during the development of a SARS vaccine. The basic premise is that the antibodies produced by the immune system are protective against infection as long as their titre is high enough in the body. However, over time the antibodies start to decline and at some point their titre drops low enough to promote ADE, which leads to much more serious infections when challenged by the same or similar virus.

A recent article in Nature discussed this problem in relation to the development of a safe and effective SARS-CoV-2 vaccine:

"Defining the titres of neutralizing antibodies that are protective, ensuring that COVID-19 vaccines can achieve these titres and avoiding waning of antibodies to subneutralizing levels through frequent boosting will be important to minimize the possibility of ADE"

Jeyanathan, M., Afkhami, S., Smaill, F. et al. Immunological considerations for COVID-19 vaccine strategies. Nat Rev Immunol 20, 615–632 (2020). [link to doi.org (secure)]

There you have it! You can start to see how this is going to play out. After people start getting vaccinated we will continue to see spikes in deaths due to ADE kicking in as antibodies start waning in people. That is when the scientists and media will tell people that ADE is the problem and that the solution requires two things: 1) continued booster shots and 2) elimination of the virus circulating in the population which means that all of the anti-vaxxers will be put firmly in the crosshairs.

This IS the game plan. Its success completely depends on how many people take the FIRST shot.