This years flu vaccine only 10% effective against dominant strain H3N2 [View all]

To get an idea of what a flu season in the U.S. will look like, scientists like Schaffner observe what happens in Australia, which experiences winter and the flu while Americans are having summer. In the summer of 2017, the flu was diagnosed in more Australians than the previous season — 168,337 versus 91,000 — with H3N2 predominant.

How effective is the 2017 flu vaccine?

Unfortunately, the flu vaccine in Australia, which is the same one available this fall and winter in the United States, was only 10 percent effective in preventing illness from H3N2.

“Typically in years when the predominant strain is H3N2, there are more hospitalizations, more severe disease and people tend to get sicker,” said Dr. Michael Ison, a professor of infectious disease and organ transplantation at Northwestern University’s Feinberg School of Medicine.

Also, the vaccine protects against other flu strains.
“The protection against the others is much higher — 50 to 70 percent,” Schaffner said.