In a bid to stay ahead of the relentless evolution of the COVID-19 virus, U.S. government advisors declared on Wednesday that it was time to revise the formula for its intended fall vaccine, focusing on a strain known as JN.1. These discussions are drawing on the lessons from the past as we brace for future surges of the virus.
Though the relatively placid flow of cases paints an optimistic picture today, it obscures the inevitability of future outbreaks, against which manufacturers need ample time to craft effective defenses. Three eminent players in the vaccine field, Moderna, Pfizer, and Novavax, have already conducted trials using doses tailored to stave off the JN.1 variant, a formidable adversary which took center stage last winter.
However, mere months later, an array of offshoots from JN.1 are gaining traction, spurring Moderna and Pfizer to experiment with a subtly altered vaccine formula devised to counter the most prevalent subtype in the U.S, referred to as KP.2.
This rise of this new contender has put FDA officials in something of a quandary when it comes to choosing the ultimate formula for the fall vaccine. In an advisory meeting held on Wednesday, FDA officials elected for the next vaccine to be rooted in the JN.1 “lineage”. Nonetheless, FDA Vaccines Chief, Dr. Peter Marks, challenged his committee to fine-tune their verdict, and consider whether KP.2 might be the more sound selection for the autumn vaccine. Drawing an analogy to his grocery shopping habits, Marks questioned, “if this evolves further in the fall, will we regret not having been a little bit closer?”
While positing KP.2 as a potential threat, the panel wasn’t convinced that it would remain a significant threat by autumn. Hence, given the current situation, they favored the progenitor JN.1 variant over predicting which of its descendents might become dominant in the ensuing months.
One of the advisors, Dr. Melinda Wharton from CDC, aptly put it: “Having a vaccine that’s the trunk of the tree rather than the branches makes sense to me”. This would lend cross-protection against any additional subtypes sprouting over time.
Americans have been prepped to anticipate annual updates to their COVID-19 vaccines, paralleling the common practice of receiving updated flu shots each fall to effectively combat the prevailing strains. With the virus’s knack for spawning new, resistant varieties and the waning immunity from earlier vaccines or infections, these updates are crucial to maintaining strong defenses.
The vaccine that was deployed last fall had targeted a different segment of the coronavirus family tree. Despite public anxiety around COVID-19 having lessened, recent examination of data from the Veterans Affairs hospitalizations this past winter showcased that COVID-19 still outpaced the flu in direness.
According to Moderna, Pfizer, and Novavax, JN.1-specific vaccines should be available by fall, though the specific quantities have yet to be disclosed. As has been the norm, the CDC will advise on the rollout of these updated vaccine shots, indicating who should receive them and when.
