Flu season explainer: the warning signs to look out for over Christmas - and how effective is the vaccine?

"Flu cases rose to nearly 1,000 last week, with a total of 264 hospitalized, raising concerns about the impact of Christmas socializing on virus spread."

"The flu vaccine is most effective against the A(H1)pdm09 strain, but there's a warning that its effectiveness against A(H3N2) is lower, especially for vulnerable populations."

Read at Irish Independent