The U.S. Centers for Disease Control and Prevention on Wednesday recommended GlaxoSmithKline Plc’s Rotarix vaccine to prevent rotavirus in children, an infection that causes gastroenteritis (vomiting and diarrhea) in infants and children.

The vaccine, known as Rotarix, was approved by the U.S. Food and Drug Administration in April to be given in a two-dose series to infants from 6 to 24 weeks of age to protect them against rotavirus gastroenteritis caused by G1, G3, G4 and G9 strains of rotavirus.

The federal advisory panel concluded that Rotarix should be added to the recommended vaccines for infants as well as Merck and Co.’s rotavirus vaccine Rotateq approved in 2006 for kids aged 2 months, 4 months, and 6 months.

Rotateq is usually given in three doses over the course of six months, being Merck’s second best selling vaccine last year with revenue of $525 million.

Both vaccines are considered equally efficient, the single difference consisting in the number of doses.

According to CDC data, rotavirus activity was delayed by about three months during the ongoing season compared with the start for the previous 15 years. The season began at the end of February instead of November, the usual start time, and the season peaked at the end of April instead of March, the usual peak time. This delay may have to do with the efficiency of Merck’s vaccine. That’s why the CDC wants Glaxo’s new vaccine on the list of recommended vaccine for children.

Rotavirus infection usually hits children before age five, causing about 2.7 million cases in the US every year – about 55,000 to 70,000 of those require hospitalization. The infection also causes between 20 and 60 death per year. Worldwide, it kills an estimated 500,000 children a year, mostly in developing countries. Frequent hand washing is the best way to limit the spread of rotavirus infection.

Merck and Glaxo’s rotavirus vaccines do not have serious side effects. In 1998, a rotavirus vaccine was licensed for use in the United States, but in 1999, the manufacturer withdrew it after it was discovered that the vaccine might have contributed to an increased risk for bowel obstruction.