“…Meanwhile, pathogen evolution has continued generating new variants under the influence of vaccine-driven evolutionary pressure, and while measles and rubella vaccines seem to resist the evolutionary pressure, the mumps vaccine shows signs of failure. Despite the remarkable public health success of the mumps vaccine, evidence of virus escape from vaccine-induce immunity is piling up [ 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 ], suggesting that a new vaccine with better-matched epitopes or a different strategy might be needed soon. Although there were numerous trials to make a universal influenza vaccine (reviewed in Reference [ 28 ]), most influenza vaccines approved today still contain the inactivated virus, its subunits or purified hemagglutinin and neuraminidase of four influenza viruses (subtypes H1N1 and H3N2 of type A and lineages Victoria and Yamagata of type B) [ 29 ].…”