Vaccines are the best option for the prophylaxis and
control of a pandemic; however, the lag time between
virus identification and vaccine distribution exceeds 6
months and concerns regarding vaccine safety are a grow-ing issue leading to vaccination refusal. In the short-term,
antiviral therapy is vital to control the spread of influenza.
To date, only two classes of anti-influenza drugs have
been approved: inhibitors of the M2 ion channel, such as
amantadine and rimantadine, or neuraminidase inhibitors,
such as oseltamivir or zanamivir [3]. Treatment with
amantadine, and its derivatives, rapidly results in the
emergence of resistant variants and is not recommended
for general or uncontrolled use [4]. Among H5N1 isolates
from Thailand and Vietnam, 95% of the strains have been
shown to harbor genetic mutations associated with resis-tance to the M2 ion channel-blocking amantadine and its
derivative, rimantadine [5]. Furthermore, influenza B
viruses are not sensitive to amantadine derivatives [6]