Current Recommendations on MMRV combination vaccine in India
Keywords:
Immunization, MMRV vaccine, Immunogenicity, Seroconversion rate, Advisory Committee on Immunization Practices (ACIP).Abstract
Two MMRV vaccines have been available since 2000. ProQuad (Merck & Co., Inc, West Point, PA; Merck) and Priorix-Tetra (GlaxoSmithKline Biologicals, Rixensart, Belgium; GSK). Both have been widely used in USA, Australia, Canada, and many European countries. The MMRV vaccine was developed based on the existing MMR and varicella vaccines 1,2. Licensed ProQuad and Priorix-Tetra have different measles virus strains (Edmonston strain and Schwarz strain, respectively) with the same titer ( > 10 3.0 tissue culture 50% infective dose, TCID50). Mumps virus strain in Priorix-Tetra (RIT 4385 strain, titer > 10 4.4 TCID50) is derived from what is used in ProQuad (Jeryl Lynn strain, titer > 10 4.3 TCID50). ProQuad and Priorix-Tetra have same rubella virus strain (Wistar RA 27/3 strain) and titer (>10 3.0 TCID50). They also have same varicella virus strain (Oka strain), but with different titers (> 10 3.99 and > 10 3.3 plaque-forming units, respectively).