Variant Influenza Viruses Confirmed in Canada
Separate cases of variant influenza viruses have been found in two unrelated individuals in different communities in southern Manitoba, Canada. One is a case of human influenza A(H1N2)v and one is a case of human influenza A(H1N1)v, reported the Manitoba Government on April 30, 2021.
The cases are the result of two different viruses and based on the case investigations, they are not linked. These cases have been reported to the Public Health Agency of Canada in accordance with international health regulations.
These two flu viruses are related to influenza viruses that circulate in pigs. Influenza viruses from pigs (swine flu) do not normally infect humans.
However, sporadic human infections with influenza viruses that normally circulate in pigs have occurred. When this happens, these viruses are called ‘variant viruses’.
Human influenza A(H1N1)v is rarely seen in humans. This is the second-ever case reported in Canada; the first was reported in Ontario in September 2012. Two human influenza A(H1N1)v cases were detected in the U.S. during the 2020-21 season.
In most cases, variant flu viruses have not shown the ability to spread easily and sustainably from person to person.
Sporadic human cases of variant influenza have been reported over the past decade in North America. Human influenza A(H1N2)v is rarely seen in humans, with only 29 cases reported globally since 2005, and no cases in Canada until one was reported in Alberta in October 2020.
The same influenza antiviral drugs used to treat seasonal flu can be used to treat variant virus infections. Seasonal flu shots are not protective against 'swine flu,' stated Health Canada on April 30, 2021. Vaccines to protect against 2009 H1N1 are widely available, says the U.S. CDC.