As temperatures begin to drop and people's minds turn to winter weather, the flu is also making its annual comeback. But how do scientists decide what flu strains to vaccinate against each year?

I spoke to the B.C. Centre for Disease Control to learn about the sophisticated, and global process of monitoring, cultivating and growing the influenza vaccination that begins almost a full year before the start of the November-April flu season.

To find out more information about the flu vaccine and how it protects you, head to the website
http://www.bccdc.ca/default.htm for lots of useful information.

If you have a science question you'd like answered, send Johanna Wagstaffe a tweet (@JWagstaffe) or an email at johanna.wagstaffe@cbc.ca.