S. Food and Drug Administration (FDA) has approved its lower-dose Covid-19 vaccine for adults aged 65 and older, as well as individuals aged 12 to 64 who have at least one medical condition that heightens their risk of severe Covid-19. This FDA approval, granted on a recent Friday, is targeted at those who have already received a previous Covid-19 vaccine.

According to Moderna's press release issued on Saturday, the newly approved vaccine, known as mNEXSPIKE, is expected to be available in the United States for the 2025-26 respiratory virus season beginning in the fall. In addition to this new vaccine, Moderna is updating its original vaccine to target the LP.8.1 variant, with an application submitted to the FDA for this updated formula in May.

The mNEXSPIKE vaccine comprises only one-fifth of the original Covid vaccine dose, Spikevax, providing an alternative for those seeking a lower-dose option. However, it's important to note that this new vaccine is not intended to replace the existing Covid vaccines. Despite the inclusion of young, healthy adults in Moderna's clinical trials, they will not be eligible to receive this new vaccine.

The approval process mirrors the limitations the FDA imposed on Novavax's Covid vaccine last month, restricting its use primarily to older adults and those with underlying medical conditions. This recent approval marks the first sanction by the FDA since the Trump administration called for more stringent restrictions on vaccine eligibility and approvals.

In line with recent directions, the FDA will focus its approval of updated Covid vaccines on older adults and younger people with underlying health conditions. Additionally, Health and Human Services Secretary Robert F. Kennedy Jr. announced that the Centers for Disease Control and Prevention (CDC) would cease recommending Covid vaccines for healthy children and pregnant women. Nonetheless, the CDC's website indicates that parents may consult a doctor if considering the Covid vaccine for children aged six months and older.

Moderna's new vaccine, mNEXSPIKE, was tested using an "active comparator" method, a generally more ethical approach than using an inert placebo. According to Moderna, the trial involved about 11,400 participants aged 12 and older. The results showed that the new vaccine generated higher antibody levels compared to the company's original Covid shot. Furthermore, the new vaccine caused fewer local reactions like redness or swelling at the injection site, while systemic reactions such as fever, headaches, or chills were comparable between the two vaccines.

Key side effects reported for mNEXSPIKE include pain at the injection site, fatigue, headache, and muscle pain. The approval of this new lower-dose vaccine marks a significant step towards providing targeted Covid-19 protection for vulnerable segments of the population.