In the year a combination vaccine for measles, mumps, rubella and varicella became available

In the year 2015 a combination...

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The MMRV vaccine combines the attenuated virus MMR (measles, mumps, rubella) vaccine with the addition of chickenpox vaccine or varicella vaccine (V stands for varicella).

Several companies supply MMRV vaccines. ProQuad is marketed by Merck and was approved in 2005 for use in the United Statesby the Food and Drug Administration for children ages twelve months through twelve years. 

Hello userthe correct answer is b.)because marburg virus causes marburg virus disease in humans and nonhuman primates, a form of viral hemorrhagic fever hope this : )