Medical experts advise the public to get an influenza vaccine before flu begins spreading in the community.
It takes about two weeks after vaccination for antibodies that protect against flu to develop in the body, so make plans to get vaccinated early in fall, before flu season begins.
The CDC (Centres for Disease Control) recommends that people get a flu vaccine by the end of October. Getting vaccinated later, however, can still be beneficial and vaccination should continue to be offered throughout flu season, even into January or later.
What viruses will the 2018-2019 flu vaccines protect against?
There are many different flu viruses and they are constantly changing. The composition of U.S. flu vaccines is reviewed annually and updated as needed to match circulating flu viruses. Flu vaccines protect against the three or four viruses (depending on vaccine) that research suggests will be most common. For 2018-2019, trivalent (three-component) vaccines are recommended to contain:
A/Michigan/45/2015 (H1N1)pdm09-like virus
A/Singapore/INFIMH-16-0019/2016 A(H3N2)-like virus (updated)
B/Colorado/06/2017-like (Victoria lineage) virus (updated)
Quadrivalent (four-component) vaccines, which protect against a second lineage of B viruses, are recommended to contain:
the three recommended viruses above, plus B/Phuket/3073/2013-like (Yamagata lineage) virus
Influenza activity is at interseasonal levels across the country.
The majority of regions in Canada are reporting no influenza activity.
All indicators of influenza activity are at low levels, as expected for this time of year.
Influenza A is the most common influenza virus circulating in Canada.
Influenza and other respiratory viruses are monitored weekly and results reported every Thursday in the FluWatch report via the Respiratory Virus Detections in Canada Report.
