said Thursday that the Food and Drug Administration has agreed to review an experimental vaccine designed to deal with four childhood diseases in a single vaccination.
The company said it expects the FDA to act by July on the vaccine called Proquad, which provides protection for measles, mumps, rubella (German measles) and varicella (chicken pox). The vaccine is designed for children in the age range of 12 months to 12 years.
Proquad combines two existing Merck vaccines, Varivax for chicken pox and M-M-R II for the three other diseases. Merck submitted the application for Proquad on Aug. 31 and received notification of the FDA's acceptance of the application this week.
Merck shares fell 46 cents, or 1.6%, to $27.41. Investors remain concerned about the company's exposure to lawsuits over its painkiller Vioxx, which the company recalled for safety reasons after several years on the market.