US Food and Drug Administration (FDA) issued a statement in follow up to the May 7, 2010 Vaccine and Related Biological Products Advisory Committee meeting where available results from testing for the presence of porcine circovirus (PCV) in rotavirus vaccines were presented. The US FDA recommended that health care professionals resume the use of Rotarix and continue the use of Rotateq (Rotavirus Vaccine, Live, Oral, Pentavalent). Merck is fully committed to working closely with the US FDA, and regulatory agencies throughout the world, to continue to conduct and share comprehensive research related to the detection of DNA from PCV1 and PCV2 in Rotateq and to take appropriate action.

The US FDA stated that they have no evidence that PCV1 or PCV2 poses a safety risk in humans, and neither is known to cause infection or illness in humans. The US FDA also noted that the benefits of rotavirus vaccines are substantial and that these benefits outweigh the risk, which is theoretical.

In March 2010, an independent research team and the US FDA tested for PCV DNA in rotavirus vaccines; at that time, PCV DNA was not detected in Rotateq by the assays that were used initially. Subsequently, Merck initiated PCV testing of Rotateq using highly sensitive assays. Merck's testing detected low levels of DNA from PCV1 and PCV2 in Rotateq. Merck immediately shared these results with the US FDA and other regulatory agencies.

Merck will also work with scientific experts and regulatory authorities throughout the world to further understand current and emerging technologies and evaluate how they may supplement our current methods of quality assurance.

Merck is confident in the safety profile and quality of Rotateq. Rotateq was studied in nearly 70,000 infants in one of the largest pre-licensure vaccine clinical trials ever conducted. The safety profile of the vaccine has been and continues to be extensively evaluated by the FDA, the U.S. Centers for Disease Control (CDC), other worldwide regulatory agencies, and Merck.

An estimated 37 million doses of Rotateq have been distributed worldwide. In the US, Rotateq is indicated for the prevention of rotavirus gastroenteritis in infants and children caused by serotypes G1, G2, G3 and G4 when administered as a three-dose series to infants between the ages of 6 to 32 weeks. The first dose should be administered between 6 and 12 weeks of age, with the subsequent doses administered at 4 to 10 week intervals. The third dose should not be given after 32 weeks of age.

Rotavirus is a leading cause of severe acute gastroenteritis in infants and young children. Rotavirus is highly prevalent and highly contagious, infecting nearly all children by age 5, many more than once, in both developed and developing countries.