Failed to understand the logic of "the new virus does seem susceptible to the flu drugs"

If "the new virus does seem susceptible to the flu drugs oseltamivir (Tamiflu) and zanamivir (Relenza)," how could doctors announce/use the flu drugs (Tamiflu) and (Relenza) to treat the patients infected by the new virus?

Context:

"Right now, we have no idea how many people may have been affected who didn't have severe disease," says García-Sastre. Milder infections are a strong possibility, given the previous outbreaks of other H7 viruses in humans, which have mostly resulted in mild respiratory disease and conjunctivitis.
Thankfully, the new virus does seem susceptible to the flu drugs (Tamiflu) and (Relenza). But if it does show signs of spreading between people, producing an effective vaccine will be crucial. Potential vaccine strains have already been made from previous H7 viruses, so one important task is to work out whether these will also protect against H7N9, Daniels says.

More:
http://www.newscientist.com/article/dn23350-new-flu-strains-genes-probed-as-china-culls-poultry.html