The mutated virus is becoming a problem for existing vaccines and therapeutics. Existing mRNA vaccines are based on short epitopes of viral proteins and have a severe limitation in preventing escape of mutant viruses from them. In the case of antibodies, they are made monoclonal and the problem is the same. Basically, the designs are becoming useless very soon after introduction. In the recent article by Wang et al in bioRxiv https://www.biorxiv.org/content/10.1101/2021.01.25.428137v2.full.pdf+html, the limitations were observed clearly for the South African variant SAdelta9 that was practically resistant to the Eli Lilly’s LY-CoV555 therapeutic antibody. The Moderna and Pfizer vaccines were also having problems with the new variants. Reconvalescent patients’ sera were about an order of magnitude less effective in neutralizing the mutated viruses.
In summary, the strategy of using short epitopes either in vaccines or monoclonal antibodies as the basis of vaccines/therapeutics has backfired. The result is not surprising as the strategy to have a successful therapeutic/vaccine has to be based on at least 3 targets. In this case, we have 1 target and 1 epitope.
We wish all researchers good luck in their efforts. The planners, however, should rethink the strategy to avoid chasing tails in the future.