On Oct. 5, 2021, Moderna announced that the European Medicines Agency (EMA) had authorized a third dose of the Moderna COVID-19 vaccine (Spikevax) given at least 28 days after the second dose to severely immunocompromised individuals 12 years of age or older.

A growing number of studies have shown the benefit of a third dose of COVID-19 vaccine in immunocompromised subjects. In particular, a recent double-blind, randomized controlled trial of 120 individuals who had undergone solid organ transplant procedures (heart, kidney, kidney-pancreas, liver, lung, pancreas) demonstrated that a third dose of the Moderna COVID-19 vaccine improved immune response compared to placebo. In the study, the third dose was generally well tolerated.

Spikevax (formerly known as COVID-19 Vaccine Moderna) is an mRNA vaccine against COVID-19 encoding for a prefusion stabilized form of the Spike (S) protein. On December 18, 2020, the U.S. FDA authorized the emergency use of the Moderna COVID-19 Vaccine in individuals 18 years of age or older. Moderna had received emergency (or other conditional, interim or provisional) authorization for use of its COVID-19 vaccine in adults from health agencies in more than 50 countries and an Emergency Use Listing (EUL) from the World Health Organization (WHO).