One of the most prevalent and contagious viruses, H1N1 has three categories – A, B and C.
Links:
[1] http://admin.indiaenvironmentportal.org.in/news/swine-flu-outbreak-how-protect-yourself-h1n1-virus
[2] http://admin.indiaenvironmentportal.org.in/category/newspaper/statesman-new-delhi
[3] http://admin.indiaenvironmentportal.org.in/category/thesaurus/swine-flu
[4] http://admin.indiaenvironmentportal.org.in/category/thesaurus/influenza
[5] http://admin.indiaenvironmentportal.org.in/category/thesaurus/infectious-diseases
[6] http://admin.indiaenvironmentportal.org.in/category/thesaurus/health-effects
[7] http://admin.indiaenvironmentportal.org.in/category/thesaurus/health