LETHBRIDGE – More people in the southern health zone are receiving vaccines against such strains of influenza, and this can be part of what is the reason for the relatively low infection, hospitalization and mortality this year.
In the southern health zone, nearly 95,000 people have been vaccinated this flu season, compared with just over 92,000 in 2017/18 and around 88,000 in 2015/16.
Doctor Vivian Suttorp says that until now, the dominant influenza virus is the A-H1N1 influenza virus, which is very similar to the one that caused 428 deaths in Canada and more than 33,000 hospitalizations in 2009/10.
According to the latest figures on the UGS website, there was only one death link in the southern zone, 54 hospitalizations, 302 cases of laboratory confirmed influenza A and 2 of influenza B.
Calgary has so far seen 9 deaths, Edmonton 7, Central Health Zone 9 and North Zone 2.
There were also nearly 2,000 hospitalizations and nearly 500 hospitalizations in Calgary, 629 infections, and 145 hospitalizations in the Central Zone, nearly 1,000 infections and 300 hospitalizations in Edmonton and over 1,100 infections and more than 170 hospitalizations in the northern zone.
Suttorp says one of the interesting things this year is that there have been no outbreaks in continuing care facilities here.
"So, any older facility or in our hospitals, which talks about the rates of immunization in the elderly, it's a fact that this influenza A affects the elderly, but not so much as in the younger ones.
"Where we see many numbers in previous years is when we have a type of epidemic. So if we have an epidemic at an institution for the elderly, it's common – even if you place a lot of control infections in place – there may be many individuals who receive this because they are together in a common environment. The fact that we did not have any epidemics, and we have very good immunization rates for our elderly and the vaccine is very effective, we have not seen those epidemics. "
She adds that those people who were hospitalized in the province, 80 per cent were not vaccinated. Most of them were also under the age of 65, and many were also children who had no immunity to the H1N1 virus.
"We see a more serious disease in young people where our rates of immunization are the lowest," explains Suttorp.
This year, the vaccine is more than 70 per cent effective. Compared with 2017/18 and 2013, when vaccines were not such good matches.
So, why is this year's vaccine more effective than in recent years?
"Annually, the World Health Organization (WHO) projects, looking at all the surveillance data that they are trying to include in the Northern Hemisphere vaccine and South Hemisphere vaccine. When this is the dominant year for influenza A-H3N2 as last year and the previous year, that the specific virus is changing faster, and even during that 6-month influenza season, the virus has a type of change already, so the vaccine is less effective compared to H1N1. It does not change so fast. "
So this means that for those who received H1N1 influenza in 2009, they may have immunity from this annual H1N1 virus because it is similar.
However, Suttorp warns that boosters are needed because there are other types that are contained in this year's vaccine, including influenza B, which may also become more common.
"When we have the peak of influenza A, as we made a sort of peak in early January, it's not atypical that we have a" second wave "of a different influenza virus in one of the influenza viruses B. So, we can" T not be safe from U.S ".