Related by context. Frequent words. (Click for all words.) 61 serotypes 56 serogroups 52 serotype 50 pneumococcal bacteria 48 pneumococcus 48 S. pneumoniae 47 Streptococcus pneumoniae 46 causes chickenpox 45 varicella zoster virus 44 pandemic influenza virus 43 subtypes 41 swine origin 41 genotypes 41 viral pathogens 41 S. aureus 40 herpes viruses 39 bacterial strains 39 MRSA strains 38 respiratory viruses 37 clades 37 Hepatitis C virus 37 vaccinia virus 37 pandemic H#N# virus 37 virulent strains 37 H#N# subtype 36 highly pathogenic H#N# virus 36 USA# [002] 36 strains 36 H#N# influenza strain 36 mutant genes 36 RNA viruses 36 epitopes 36 Aspergillus 35 avian influenza viruses 35 viral strains 35 vaccinia 35 fungal pathogens 35 antibiotic resistant strains 35 E. coli bacterium 35 multidrug resistant tuberculosis 35 influenza strains 34 mycoplasma 34 viral infections 34 Influenza viruses 34 pathogens 34 staphylococcus aureus 34 bacilli 34 resistant strains 33 lactic acid bacteria 33 mycobacteria 33 avian flu outbreaks 33 Bacillus anthracis 32 antigens 32 H#N# viruses 32 transgenes 32 pathogen 32 VLPs 31 rhinoviruses 31 avian flu viruses 31 mutant strain 31 influenza virus 30 influenza viruses 30 phage 30 viruses 30 virulence factors 30 virulent strain 29 bacterial strain 29 antibodies 29 bacterium 29 mutant strains 28 susceptibilities 28 flu strains 28 strain 28 contagions 27 flu viruses 27 receptor proteins 26 Flu viruses 26 isolates 26 lineages 26 burdens 24 virus 24 flu virus 24 stressors 23 odorants 23 afflictions 23 Strains 23 avian viruses 20 genetic sequences 19 sniffles 18 stress 18 maladies 14 stresses 13 discordant 12 straining 11 pressures 10 timbres 9 crises 8 schisms 7 strained 6 rifts 6 frictions