By Michalezki, Amanda on January 12, 2019.
The incidents of influenza continue to rise across the country, but this flu season is significantly different.
The predominant Influenza A H1N1 strain is circulating earlier this year than before, the same virus that caused the 2009-10 pandemic which hasn’t surfaced in the last few years. This virus tends to target children and younger adults and this season is no exception as different strains impact different age groups.
The BC Centre for Disease Control laboratory-confirmed cases of the H1N1 flu, show that about one-third of all detections this season have been in children nine years of age or younger due to lack of immunity prior to the H1N1 epidemics.
Dr. Vivien Suttorp, Medical Officer of Health for Alberta Health Services South Zone, said other flu strains may circulate in different geographies at different times.
In 2013, during another pandemic of H1N1, Suttorp was relaying to the public how they’ve used up all of their vaccines when people realized the severity of the virus and rushed out to get their flu shot.
This flu season, the virus is resurfacing again with a total of 4,700 confirmed cases to date.
In previous seasons, another influenza strain called H3N2 dominated. This particular strain is especially hard on the immune systems of older adults since it carries a higher risk of complications such as pneumonia that can lead to hospitalization or even death.
AHS has had very few outbreaks of H3N2 in the South Zone thus far. The vaccine for Influenza A H3N2 is not as effective as the vaccine is for H1N1, though, which is also an Influenza A strain. It is due to the H3N2 virus changing so quickly and why vaccines are needed every year, said Suttorp.
“Since October, over 80 per cent of hospitalized cases in Alberta were not immunized. We don’t see that in other years when it’s the H3N2 predominant strain because that vaccine is not as effective,” said Suttorp.
The South Zone has had no outbreaks of H1N1 this season in continuing-care facilities for seniors because the vaccines are very effective, and seniors in care facilities are very well immunized, said Suttorp.
The influenza vaccine this year covers four strains for protection – Influenza A H1N1 and Influenza A H3N2, as well as two types of strains of Influenza B.
The Influenza A viruses act differently but all impact the respiratory system, said Suttorp.
She added people may feel better but it may take longer for their respiratory system to recover.
The number of people every week who are testing positive for influenza by lab tests is less this last week, according to recent AHS data, but if people are not immunized for H1N1 or any of the strains, they can still get a different strain later in the flu season, which usually lasts until early March to the end of April.
“It’s not a live virus in the vaccine, the vaccine makes immunity to the proteins on the outside of the virus,” said Suttorp. “As soon as you see the virus, you can get exposed to it, and you have antibodies that are already primed and ready to attack that virus so you don’t get ill.”
Although, the vaccine doesn’t give 100 per cent immunity, the effects will be much milder with less risk of complications and less risk of hospitalization.
Suttorp said the earlier you are immunized once the vaccine is available the better, since it takes up to two weeks to prime the system for optimal immune response.
Since September, the Public Health Agency of Canada said 414 children under the age of 16 have been hospitalized for the flu with the highest estimated rate of admission among kids under five years of age which is more than double the 195 logged during the same period in 2017.
PHAC showed in their most recent data from Dec. 29, that there have been 13,796 laboratory-confirmed influenza cases across Canada. Provinces and territories reported 1,046 hospitalizations and 24 deaths, with most cases having occurred in people under the age of 65.
Individuals who become sick, no matter with which strain (H1N1 or H3N2), won’t be able to detect much of a difference as both still produce symptoms of fever, cough, achy muscles and joints, and general malaise.
Suttorp suggests that if you’re sick to stay home, practise cough etiquette, wash your hands, and make sure your immunizations are up to date.
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