<prompt> H5N1 is a strain of:Avian fluNew vaccine against AIDSAgent for Japanese encephalitisCauses Chikungunya fever  <response>: Ans. is a i.e., Avian flu Ref: Park, 22nde, p. 145 At present three types of influenza viruses are circulating in the world: AH1 N1 ,AH3 N2 , and B viruses. WHO global surveillance activities have identified human infection with a new influenza virus called AH5 N1 ,in Hong Kong in mid 1997. However, the possibility that the outbreak heralded a global influenza pandemic did not materialize and it is transmitted to man only from birds, requires close respiratory contact. 