<prompt> Virus which has more than one serotypes -MeaslesMumpsRubellaInfluenza  <response>: Ans. is d i.e., Influenzao Influenza virus is an enveloped RNA virus containing 8 pieces 8 segments of single stranded RNA.o There are three viral subtypes : i Type A causes all pandemics and most epidemics; ii Type B: and iii Type C not circulating currently.o Currently the influenza viruses circulating in the world are : H1 N1 of type A causes swine flu; H2N2 of type A; H3 N2 of type A; H5N1 of type A causes birdflu or avian influenza; H7 N9 of type A caused epidemic of avian influenza in China in 2013; and type B. 