The flu can also cause a general feeling of fatigue or malaise, Ray says, as well as gastrointestinal issues like diarrhea ...

Different combinations of these give rise to the influenza A virus subtypes, including the H1N1, H2N2 and H3N2 subtypes that have afflicted humankind for over 100 years. The first inactivated ...

The A(H2N2) virus family was in circulation for ... The vaccine then became trivalent with the strains A(H1N1)/A(H3N2)/B (Figure 1). Although lower degrees of effectiveness have been observed ...

but offered significantly more protection against infections caused by influenza B compared to those caused by either influenza A(H1N1) or A(H3N2), according to a University of Minnesota report ...