[Image courtesy of Production Perig/Adobe Stock]
Against the backdrop of a nearly 16% spike in COVID-19 hospitalizations in late August, according to CDC data, federal authorities are gearing up to greenlight updated boosters. Moderna announced that its latest COVID vaccine is effective against this new strain. Meanwhile, Pfizer revealed positive preclinical data for its vaccine, developed in collaboration with BioNTech.
In late August, Novavax also announced that its updated protein-based XBB COVID vaccine candidate retained neutralizing antibody responses to several emerging subvariants, including EG.5.1 and XBB.1.16.6. Unlike the mRNA-based boosters from Pfizer and Moderna, Novavax’s COVID vaccine would be the sole protein-based non-mRNA vaccine option available for the upcoming fall season.
The following visualization, based on CDC data, highlights the top SARS-CoV-2 variants for August and September 2023. The BA.2.86 (Pirola) variant, which Moderna and Pfizer highlight as a concern given its potential to break through existing immunity, did not appear among the top 10 for this period. Health authorities have found it in a handful of states.
While the BA.2.86 omicron subvariant possesses a high mutation count, recent findings from the Barouch Lab at Harvard found that neutralizing antibody (NAb) responses to BA.2.86 were lower than to BA.2, an omicron subvariant that surged in 2022. Yet, that response is in line with, or even superior to, reactions to other currently circulating variants.
Compared to related strains, the BA.2.86 variant exhibits over 30 mutations in its spike protein. Experts say BA.2.86 is unlikely to fuel outbreaks in line with the early Omicron waves, according to an article in Nature. Jesse Bloom, a viral evolutionary biologist quoted in that article, posits that such extensive mutations in the spike protein appear to stem from chronic SARS-CoV-2 infections.
COVID vaccines such as Pfizer’s Comirnaty and Moderna’s Spikevax drove huge pharmaceutical revenues in 2022, with Comirnaty topping the best-seller list at $55.92 billion and Spikevax at $18.43 billion.
But the financial outlook for COVID-19 vaccines has shifted as the pandemic progresses. Moderna’s stock has down almost 40% year-to-date, Pfizer’s has fallen 33% and BioNTech has seen a 20% dip over the same period. While Novavax’s stock remains relatively stable this year, its share price has fallen far from its $290-high in early February 2021.