Vaccine against influenza ineffective one day, not always

vaccin(Quebec) Casually, the flu season approaches. And with it comes the flu vaccine, including the exceptional lack of efficiency last year could discourage people from getting bitten this year. In an interview to the Sun, two specialists are wanted reassuring.

“The flu shot is a bit like the actions we have in stock. You have to see that on a 10-year horizon, in the long term. Over 10 years, it may be that the vaccine is less effective for three or four years. But we must always remember that less efficient does not mean zero efficiency. It can reduce the severity of symptoms and prevent complications related to the flu, “says Dr. Guy Boivin, microbiologist and infectious disease specialist at the Centre hospitalier universitaire de Québec and microbiology professor at Université Laval.

It is true that the 2014-2015 vaccine was disappointed with an efficiency of 0% …. “Normally, the rate of effectiveness of the vaccine against seasonal flu is around 40-60%. When you have a 70% yield is very unusual, “says Dr. Gaston De Serres, medical epidemiologist at the National Public Health Institute of Quebec (INSPQ). Last year, he recalls, the vaccine protected against H1N1 strains B and, while it is especially the H3N2 that hit.

However, this is not because nature has baffled science last year it will start this year.

Unpredictable

“We expect better protection than last year, but it’s sure it will depend on the mix of influenza will circulate. It is unpredictable, “says Dr. De Serres, adding that the composition of the 2015-2016 vaccine dates back to February.

“One of the selected strains is not as close as we would like H3N2. They are cousins, but we’d better be brothers, “popularizes the doctor, explaining that” there are sometimes technical problems that may be encountered or tests that are not completed. ”

Anyway, both Drs De Serres Boivin encourage people over 65, those with chronic illnesses or immunocompromised, pregnant women (second and third quarter) and health workers to be vaccinated against influenza at the start of November.

Influenza A quadrivalent vaccine (VAQ), which protects against four different strains of influenza virus (two A and two B), is also available in Canada this year in some public immunization programs.

While Manitoba, Yukon, and several Atlantic provinces have adopted the VAQ, Quebec offers for adults a trivalent hour, which costs less than the dose that protects against quadrivalent but only three strains (two A’s and one B). More vulnerable to B strains of influenza, young children in Quebec, however, entitled to a quadrivalent vaccine intranasal.

“Of course it’s more expensive quadrivalent, but this is nothing compared to the consequences of the flu,” argues Dr. Guy Boivin, who believes that a more powerful incentive quadrivalent vaccine more people to get vaccinated.

In the Ministry of Health, it is specified that the Committee on Immunization Quebec did not recommend the offer to extend the quadrivalent vaccine to the entire population.

Quadrivalent unprofitable

According to Dr. De Serres, there is very little benefit to pay more for a quadrivalent vaccine is not as effective as the drug companies suggest. “Given all the viruses circulating, the additional gain that would be very small. There is talk of an additional yield of 5 to 10%, no more, “says epidemiologist INSPQ, adding that” the trivalent still offers cross-protection against 50% of the line B is not in the vaccine. ”

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