US FDA Approves GSK’s Priorix Measles, Mumps, and Rubella Vaccine

Earlier this month, the FDA approved GSK’s Priorix measles, mumps, and rubella (MMR) vaccine in the United States for individuals 12 months and older.

MMR vaccines are recommended in a two-dose series, the first at 12–15 months and the second between ages 4 and 6.

Although Priorix has been on the market for 25 years and is available in more than 100 countries, including all of Europe, its new availability in the US provides another MMR vaccine option that will directly compete with Merck’s M-M-R II vaccine.

“Outbreaks of measles in recent years demonstrate how quickly diseases can return without widespread immunization,” said GSK's Temi Folaranmi, VP of US Medical Affairs for Vaccines, in a press release. “Missed vaccinations during the pandemic make children even more vulnerable to vaccine-preventable diseases like measles.”

Globally, more than 400,000 cases of measles were reported in 2019, reversing decades of progress toward eradicating this disease. The World Health Organization reported that cases from January and February this year increased by 79% compared to the same period a year ago, declaring it a "worrying sign of a heightened risk for the spread of vaccine-preventable diseases."

Additionally, a recent CDC report displays a 10% drop in MMR vaccine orders in the US through its program, which immunizes roughly 50% of the country’s children and notes that 400,000 fewer US children entered kindergarten in the 2020­­–2021 school year than expected, suggesting those children may not be up to date on their vaccinations.

The approval of Priorix is based on six studies comprising 12,151 people, with more than half in the US, and 4,418 children aged 12–15 months, and the study showed comparable efficacy and side effects to Merck’s M-M-R II vaccine.