Merck vaccines eliminate US rubella health threat

Rubella, or German measles, is a viral illness that is spread by sneezing and coughing. Up to 85% of unvaccinated women exposed to the virus in the first trimester of pregnancy pass the infection to the fetus, often causing a condition known as congenital rubella syndrome, or CRS.

The more common consequences of CRS are cataracts, heart defects, hearing impairment and developmental delay, but, in some cases, CRS can result in miscarriage and stillbirth.

Meruvax (rubella virus vaccine live), Merck’s first vaccine for rubella, was licensed in the US in 1969. In 1971, Merck introduced its combination vaccine against measles, mumps and rubella, MMR, and in 1979, Merck introduced MMR II, which replaced the original rubella strain with a new strain.

Due to widespread vaccination in the US, cases of rubella have steadily declined since the introduction of Meruvax in 1969. That year, nearly 60,000 cases of rubella were reported, but by 1972, reported cases dropped by more than half to 25,501 cases. By 1979, only 12,000 cases were reported, and by 2002, only 18 cases were reported.

“Achievement of the elimination of rubella as a public health threat in the US not only represents the absence of the scourge of congenital rubella in this country, but also demonstrates the feasibility of interrupting the transmission of rubella around the world using rubella vaccines,” said Dr Walter Orenstein, director of Emory University School of Medicine’s program for vaccine policy, and former director of the National Immunization Program at the Centers for Disease Control and Prevention.