On Thursday, the World Health Organization (WHO) expert panel proposed that this years COVID-19 booster doses should be adjusted to target one of the presently prevalent XBB strains. According to the advisory group, new formulations should attempt to induce antibody responses to the XBB.1.5 or XBB.1.16 variations, but alternative formulations or platforms that yield neutralizing antibody responses to XBB lineages should also be studied.

Based on data showing that the original virus was no longer circulating in humans and that shots targeting the strain produce "undetectable or very low levels of neutralizing antibodies" against currently circulating variants, the group proposed that the original COVID-19 strain be removed from future vaccines.

At present, pharma giants Pfizer/BioNtech (PFE.N), Moderna Inc. (MRNA.O), and Novavax Inc. (NVAX.O) are already developing COVID-19 vaccines that target XBB.1.5 and other presently circulating strains.

WHOs advisory panel, which proposes modifications to the composition of future COVID-19 doses, stated that existing licensed vaccinations should be used in line with the agencys recommendations. The most recent recommendations came approximately two weeks after WHO lifted the worldwide emergency designation for COVID-19. 

(Source: https://www.reuters.com/business/healthcare-pharmaceuticals/who-recommends-new-covid-shots-should-target-only-xbb-variants-2023-05-18/ )