Sarah Travers
The U.S. Food and Drug Administration (FDA) has given the green light to new Covid-19 vaccines from Pfizer and Moderna, paving the way for their widespread availability in the coming days. This approval arrives as the United States grapples with a summer surge in Covid-19 cases, highlighting the ongoing need for updated vaccines to combat the virus’s evolving strains.
These new vaccines are designed to target the KP.2 strain, a descendant of the highly transmissible Omicron subvariant JN.1, which was prevalent earlier in the year. Although KP.2 accounted for the majority of cases in May, it now represents just about 3% of current infections in the U.S., based on the latest data from the Centers for Disease Control and Prevention (CDC). Nevertheless, Pfizer and Moderna report that their vaccines aimed at KP.2 can produce more robust immune responses against other circulating JN.1 subvariants, such as KP.3 and LB.1, compared to last year’s vaccines, which targeted the XBB.1.5 Omicron strain.
The FDA emphasized the importance of these updated vaccines, citing the decline in immunity from past Covid-19 infections and vaccinations. Consequently, the CDC recommends that everyone aged six months and older receive the updated Covid-19 vaccine along with their annual flu shot. The newly approved vaccines from Pfizer and Moderna are designated for individuals aged 12 and older, while emergency use authorization covers children aged six months through 11 years.
Pfizer has stated it will begin distributing its updated vaccine immediately, with availability in pharmacies, hospitals, and clinics nationwide anticipated within days. Moderna expects a similar distribution timeline for its vaccine. Both companies stress that staying current with Covid-19 vaccinations is among the most effective measures to prevent severe illness.
This year’s approval of updated vaccines by the FDA comes earlier than last year’s, which was issued on September 11. The sooner availability of these vaccines may provide reassurance to the public during this summer’s notable increase in Covid-19 cases. CDC data indicates that high levels of the virus are present in wastewater samples from nearly every state, offering insight into its prevalence as traditional testing has decreased.
Although Covid-19 test positivity rates and hospitalizations are rising, they remain well below the peak levels observed during the pandemic. Recent reports show that test positivity rates climbed to 18.3% in early August, slightly up from 17.9% the week before. Hospitalization rates have also risen, with approximately four Covid-19 hospitalizations per 100,000 people, compared to just one per 100,000 in May.
There is uncertainty about whether the current wave of Covid-19 will diminish by the time the new vaccines become fully effective, which typically takes about two weeks post-administration. Federal health officials have long suggested that annual updates to Covid-19 vaccinations may be necessary, given the virus’s propensity to mutate and evade immunity from previous infections or vaccinations. This strategy mirrors the yearly release of flu vaccines.
Despite the push for updated Covid-19 vaccines, it remains uncertain how many Americans will choose to receive them. Last fall, only around 22.5% of U.S. adults received the most recent Covid-19 booster. Common reasons for skipping the booster included a perceived lack of concern about the virus and busy schedules.
While Pfizer and Moderna’s vaccines utilize mRNA technology, which facilitates rapid updates to combat new virus strains, Novavax is also seeking FDA approval for its new vaccine. Novavax’s product uses protein-based technology, a well-established method applied in other common vaccines. The company is currently collaborating with the FDA to complete the review process and aims to secure authorization in time for the primary vaccination season.
As Pfizer and Moderna’s updated vaccines become available, the hope is that these new shots will provide stronger protection against the ever-changing Covid-19 virus, helping to mitigate the spread and impact of infections in the months to come.
