evolution | Mitsubishi Lancer Evolution | viral video | Underworld: Evolution | Evolution | Viral video | viral marketing | Convergent evolution | The Blind Side: Evolution of a Game | Pro Evolution Soccer | Viral phenomenon | viral hepatitis | TRON: Evolution | Tron: Evolution | Pro Evolution Soccer 6 | Neuroblastoma RAS viral oncogene homolog | Molecular Phylogenetics and Evolution | Enhanced Data Rates for GSM Evolution | convergent evolution | X-Men: Evolution | Mitsubishi Lancer Evolution X | Basic Color Terms: Their Universality and Evolution | basal (evolution) | Underworld: Evolution (soundtrack) | Trials Evolution | Tempo and Mode in Evolution | Pro Evolution Soccer 2008 | Molecular Biology and Evolution | Journal of Molecular Evolution | Evolution Records |
Vaccination has proved difficult as there are so many viruses involved and they mutate rapidly.