2017 Influenza Season Report
We’ve had another successful flu vaccination campaign this year, preparing our corporate clients for what turned out to be a country-wide influenza epidemic. The flu season started early and, as of the 4th of December, there were 234,869 laboratory-confirmed1 notifications - more than 2.5 times higher than last year!
During the peak of the season there were some negative headlines in the media about this year’s influenza vaccine and an Australian Influenza Surveillance Report 2017 Season Summary2 published by the federal Department of Health notes that its overall effectiveness was lower than expected. There are a couple of reasons for this:
- Vaccine Production Time
The virus strains that the influenza vaccination will protect against are decided each year by the World Health Organization’s Global Influenza Surveillance and Response System (GISRS)3. This is done yearly as flu viruses can mutate rapidly and the circulating strains can change. Several months before the start of the flu season the WHO provides its recommendations for both the Northern and Southern Hemispheres, to allow for time to produce adequate quantities of the vaccine, a process that can take up to six months4.
- Strain Selection
One of the virus strains chosen for the 2017 vaccine, A(H3N2), mutated after it was selected and then changed again during production. This meant it was not a good match for the dominant circulating strain during the Australian flu season, the one that is particularly harmful to the elderly. However the 2 influenza B strains contained in the vaccine were a good match.
Next year’s Southern Hemisphere quadrivalent flu vaccine will contain 5:
- A (H1N1): an A/Michigan/45/2015 (H1N1)pdm09 like virus
- A (H3N2): an A/Singapore/INFIMH-16-0019/2016 (H3N2) like virus
- B: a B/Phuket/3073/2013 like virus
- B: a B/Brisbane/60/2008 like virus
Why do we advise having the flu vaccine each year?
Influenza is not the common cold – it is a potentially life-threatening respiratory illness. People with existing medical conditions that can lead to complications from contracting influenza are eligible for a free flu vaccine each year through the National Immunisation Program. For working adults who get the flu, there is the lost time at work, the misery caused by being ill and also a risk of secondary bacterial infections such as pneumonia, bronchitis and inflammation of the heart or brain6.
The influenza vaccine is the single most effective way of preventing the flu.
Getting the flu vaccine each year means you are less likely to get the flu and less likely to have severe complications if you do get sick. You also become an important link in the so-called herd immunity - if enough people are vaccinated, it is harder for infectious diseases such as the flu (or measles etc) to spread to others who are more vulnerable, such as the elderly, newborn babies and those who may be too sick to have the vaccine. That’s three very good reasons.
1Immunisation Coalition – Influenza activity 2017 statistics accessed online: http://www.immunisationcoalition.org.au/news-media/2017-statistics/
2Department of Health “Australian Influenza Surveillance Report and Activity Updates” accessed online at: http://www.health.gov.au/internet/main/publishing.nsf/Content/cda-surveil-ozflu-flucurr.htm#current
3World Health Organization “Influenza vaccine viruses and reagents” accessed online at: http://www.who.int/influenza/vaccines/virus/en/
4US Centers for Disease Control & Prevention “Selecting Viruses for the Seasonal Influenza” accessed online at: https://www.cdc.gov/flu/about/season/vaccine-selection.htm
5World Health Organization “Recommended composition of influenza virus vaccines for use in the 2018 southern hemisphere influenza season” accessed online at: http://www.who.int/influenza/vaccines/virus/recommendations/2018_south/en/
6US Centers for Disease Control & Prevention “Flu symptoms and complications” accessed online at: https://www.cdc.gov/flu/about/disease/complications.htm