MMRV vaccine

The MMRV vaccine is a combination vaccine which combines the attenuated virus measles, mumps, rubella (German measles), and varicella (chickenpox). The MMRV vaccine has similar immunogenicity and overall safety profiles to the MMR vaccine administered with or without the varicella vaccine. The MMRV vaccine is typically given to children between one and two years of age.

Several companies supply MMRV vaccines. Proquad is marketed by Merck and was approved in 2005, for use in the United States by the Food and Drug Administration (FDA) for children ages twelve months through twelve years. An MMRV vaccine called Priorix Tetra by GlaxoSmithKline has been approved in Germany and Australia.

Recommendations
The MMRV vaccine, a combined MMR and varicella vaccine, simplifies administration of the vaccines. One 2008 study indicated a rate of febrile seizures of 9 per 10,000 vaccinations with MMRV, as opposed to 4 per 10,000 for separate MMR and varicella shots; U.S. health officials known as the ACIP therefore do not express a preference for use of MMRV vaccine over separate injections.

Adverse events
Rare but serious adverse events reported following Proquad vaccination include allergic reactions, including swelling of the lips, tongue, or face; difficulty breathing or closing of the throat; hives; paleness; weakness; dizziness; a fast heart beat; deafness; long-term seizures, coma, or lowered consciousness; seizures (jerking or staring) caused by fever; or temporary low platelet count.

For children age two and younger, the MMRV vaccine is associated with significantly more adverse events compared to separate administration of MMR and varicella vaccinations on the same day. There are 4.3 additional febrile seizures per 10,000 vaccinated children (95% CI 2.6–5.6), 7.5 additional mostly mild fever episodes per 100 vaccinated children (95% CI, 5.4–9.4) and 1.1 additional measles-like rash per 100 children (95% CI, 0.2–1.8). Febrile seizures caused by the MMRV vaccine occur 7 to 10 days after vaccination. In children age 4–6, there is no evidence for an increased risk in febrile seizures after the administration of Proquad compared to the separate administration of MMR and Varicella vaccines.

Legal status
Proquad was approved for medical use in the United States in September 2005, in the European Union in April 2006, in Australia in February 2007, and in Canada in May 2014.

Priorix Tetra was approved for medical use in Australia in November 2005, and in Canada in June 2008.