Flu vaccine offers best defence against current strain
A doctor writes: Influenza virus has arrived and it is not too late to protect yourself
By including A/Michigan/50/2015 (H1N1) pdm-like virus in the flu vaccine the experts were spot on. File photograph: David Cheskin/PA Wire
Has the flu arrived in Ireland yet?
Yes, the influenza virus is on the move here. Later in the season than other years, the latest figures from the Health Protection Surveillance Centre (HPSC) show a tripling of influenza-like illnesses for the week ending January 6th. An ILI rate of 34 per 100,000 brings us above the threshold level of 17.5 but remains short of epidemic proportions. There were 151 confirmed cases of people being hospitalised due to flu during the first week of 2019, bringing this year’s winter total so far to 282, according to the Health Protection Surveillance Centre. The centre said six people have died so far this winter.
Is the flu strain now circulating the same as last year?
No, last year influenza H3N2 and a strain of Influenza B virus were the primary bugs affecting people. This year, the most prevalent type of flu is A (H1N1).
Is this year’s flu vaccine a good match?
Yes, the Influenza A (H1N1)pdm09 which is circulating in Ireland at present is one of the three component viruses in this year’s flu vaccine. With production needs dictating a long lead-in time, the World Health Organization’s vaccine committee had to make an educated guess some 11 months ago as to the likely strains that would affect the northern hemisphere this winter. By including A/Michigan/50/2015 (H1N1) pdm-like virus in the flu vaccine the experts were spot on.
Do we know yet if this year’s virus is targeting particular groups of people?
It is too early to confirm a definite pattern, but preliminary figures from the HPSC show a high rate of hospitalisation with flu in the under 5s. People aged 65 and over had the highest rate of admission to a critical care unit as a result of flu.
Is it too late to get the vaccine?
No, the influenza vaccine continues to be available free of charge from GPs for all people in at risk groups, and from pharmacists for everyone in at risk groups aged 18 years and over. An administration charge may apply to people who do not hold medical cards or GP visit cards. If you are over 65 or have a chronic illness such as lung or heart disease and have not yet been vaccinated you should arrange to have the single flu shot without delay.
I got the vaccine last year so I think I’ll take a chance and not get it again?
That’s not a great idea. All viruses are able to mutate. They alter their genetic make-up in response to changing environmental circumstances. Influenza virus is especially good at this, which explains why you can catch flu more than once and also why it is necessary to vaccinate people annually. Seasonal influenza causes respiratory death at a rate of 4 to 9 deaths per 100,000 people; for those aged 75 and over, the mortality rate is much higher.
How will I know I have contracted the flu?
The sudden onset of symptoms such as fever, cough, sore throat, aching muscles and joints mean you should probably isolate yourself in bed. Drink plenty of fluids and take paracetamol to reduce your temperature. Most people will recover with self-care in about a week to 10 days after the onset of infection.
When do I need to see a doctor?
If you develop any of the following while you have the flu, then it is important to seek medical advice: increasing difficulty breathing, for example being unable to complete a sentence; sharp chest pains that make it difficult to breathe or cough; thick yellow or green phlegm or bloody phlegm; severe ear ache; uncharacteristic changes in behaviour such as becoming confused or appearing terrified (particularly in children); and being so drowsy as to have difficulty eating, drinking or talking.