Related by context. Frequent words. (Click for all words.) 56 easily transmissible 56 influenza viruses 55 avian influenza viruses 55 recombination 53 viral strains 52 avian virus 51 H#N# viruses 51 influenza virus 50 pandemic strain 50 interbreeding 50 flu viruses 49 mutate 49 mutations 49 mutation 48 avian influenza virus 48 virus mutates 47 highly pathogenic avian influenza 47 avian flu virus 47 transmissible 47 flu virus 47 H#N# strain 47 Flu viruses 47 speciation 47 serotype 46 flu strains 46 highly pathogenic 46 pandemic H#N# 45 influenza strains 45 genetic sequences 45 infect humans 45 organism 45 pathogen 45 antibiotic resistance 45 mutating 45 prion protein 45 pathogenicity 44 Tamiflu resistant 44 influenza pandemics 44 Mycobacterium tuberculosis 44 H#N# avian flu 44 coronavirus 44 Plasmodium 44 flu pandemics 43 H#N# avian influenza 43 retroviruses 43 virologists 42 pathogenic 42 mutates 42 Shigella 42 bird flu virus 42 amantadine 42 Plasmodium falciparum 42 micro organism 42 coli 42 mutated 41 lineages 41 respiratory viruses 41 seasonal influenza vaccine 41 influenza pandemic 41 viruses 41 hemagglutinin 41 hybridization 41 pneumococcus 41 prion diseases 41 virulence 41 swine influenza 41 causative agent 41 smallpox virus 41 recombine 41 bird flu strain 41 retrovirus 41 Kawaoka 41 bacterial strains 41 crossbreeding 41 clade 41 virulent strain 41 Avian influenza 41 pandemics 41 resistant strains 40 pandemic influenza vaccine 40 prions 40 serotypes 40 evolutionary 40 clonal 40 pandemic influenza 40 H#N# 40 genetic sequencing 40 avian influenza 40 pathogens 40 pandemic 40 bacterium 40 sparking pandemic 40 gene sequences 40 HPAI 40 genome sequences 39 H#N# virus 39 infective 39 sequencing 39 swine flu virus 39 malaria parasite 39 toxoplasmosis