GSK scores FDA endorsement for Priorix, providing vaccine to defend kids against measles

Measles is making a comeback. Chalk it up to the coronavirus pandemic and the disruption it has brought to routine doctors’ visits and the immunization schedules of children.

So the timing is right for the FDA’s approval of GSK’s Priorix vaccine for measles, mumps and rubella (MMR).

Kids age 1 and older are eligible for the shot. MMR vaccines are recommended in a two-dose series—one at 12 to 15 months and the other between ages 4 and 6.

Priorix has been on the market for 25 years, first in Germany and now in more than 100 countries including all of Europe. With its availability in the United States, it will compete with Merck’s M-M-R II vaccine.

“Outbreaks of measles in recent years demonstrate how quickly diseases can return without widespread immunization,” GSK's Temi Folaranmi, VP of U.S. medical affairs for vaccines, said in a statement. “Missed vaccinations during the pandemic makes children even more vulnerable to vaccine-preventable diseases like measles.”

In 2019, more than 400,000 cases of measles were reported around the world, reversing decades of progress toward stamping out the virus. In April, the World Health Organization said that cases from January and February were up by 79% compared to the same period a year ago and called it a "worrying sign of a heightened risk for the spread of vaccine-preventable diseases."

In addition, a recent report from the CDC shows a 10% drop in MRR vaccine orders in the U.S. through its program which immunizes roughly half of the country’s children. The report noted that 400,000 fewer children entered kindergarten in the 2020-2021 school year than expected in the U.S., meaning those children may not be up to date on their shots.

GSK’s approval is based on six studies involving 12,151 people, with more than half in the U.S., including 4,418 children between the ages of 12 and 15 months. In the studies, Priorix showed comparable efficacy and side effects to M-M-R II.


Vaccines for children aren’t traditionally big earners. Merck reported sales of $509 million last year for its battery of kids shots including M-M-R II, Varivax for chickenpox and ProQuad, for MMR and chickenpox.

Meanwhile, GSK reported sales of 260 million euros ($279 million) for its trio of Priorix, Varilrix, which defends against chickenpox, and Priorix Tetra, which protects against MMR and chickenpox.