Were you boosted, got Omicron, and still felt like death warmed over twice? It happens, and it’s no secret that endless boosting with the original vaccine won’t prevent infection with future strains and won’t prevent viral transmission as SARS-CoV-2 continues to evolve. So what are scientists doing to make the vaccine more effective?
According to the BMJ, “The changing face of the novel coronavirus has challenged scientists to modify existing vaccines to better tackle the changing characteristics of SARS-CoV-2. Yet, despite much talk of modified vaccines for variants, the world is still using largely the same original vaccines for initial rollouts and booster doses.”
Paul Bieniasz, a virologist at the Rockefeller University, New York, explains that existing vaccines are being updated. This means that new vaccines will better match the currently circulating COVID strains around the world.
This approach is used for updating the flu vaccine every year. With COVID, however, variants so far have emerged and spread faster, which limits the amount of time scientists have to identify the most important variants, modify vaccines, check their efficacy, and approve them.
Perhaps a multivalent vaccine, or pancoronavirus vaccine, may be more useful. This type of vaccine would contain a mixture of strains that could provide a broader immune response against potential future strains.
Experimental multivalent vaccines against COVID are in development. Bieniasz, whose lab is currently working on a pan-coronavirus, states these are meant to protect more broadly against sarbecoviruses, the group of viruses that SARS-CoV-2 and the original SARS-CoV derived from. These vaccines contain mixtures of parts of the spike proteins from various sarbecoviruses. An early multivalent vaccine trial shows neutralizing antibodies in response to this vaccine are produced at a similar rate to those elicited by the current mRNA vaccines.
Although the idea of a pancoronavirus vaccine sounds good, it may not be as easy or as effective as it sounds. After all, like Penny Ward, a visiting professor in pharmaceutical medicine at King’s College, London, pointed out, scientists have been working on a pan-influenza vaccine for the past 80 years yet it still doesn’t exist. No pan-virus vaccine currently exists, period.
Sources: BMJ
