Finally, it is interesting, and to a certain extent, reassuring, to note that during this 10-year period (1997) (1998) (1999) (2000) (2001) (2002) (2003) (2004) (2005) (2006) , no influenza A(H3N2) viruses isolated from this cohort of NAI-naïve children from Hong Kong, showed any evidence of naturally occurring, known NAI resistance-associated amino acid mutations (R292K and E119V).