https://www.cnbc.com/2021/04/07/covid-vaccine-long-haulers-report-symptoms-easing-after-getting-shot.html

The hypothesis is that viral reservoirs are behind long-haulers' lingering health issues and getting the vaccine may clear these reservoirs out.  Reminds me of apabetalone's MOA on the HIV virus. 

Perhaps apabetalone would have multiple actions on Covid;  cell entry blocking, virus replication inhibition, inflammation control, viral reservoir clearing by preferential cell apoptosis. 
From this study: 
""Furthermore, we showed that apabetalone (10-30 μmol/L) caused dose-dependent cell cycle arrest at the G1/G0 phase in ACH2 cells, and thereby induced the preferential apoptosis of HIV-1 latent cells to promote the death of reactivated reservoir cells."