- Influenza is a very contagious respiratory virus which is spread by sneezing or coughing commonly.
- There are two strains of influenza with many variations due to proteins within the DNA. This allows continual mutations from year to year.
- Worldwide 3-5 million people become infected every year with 250,000 to 500,000 deaths annually.
- In Australia approximately 18,000 people are hospitalized each year with 3,500 deaths.
- The World Health Organization has been monitoring and producing vaccines for influenza since 1952 with 142 monitoring centres in 112 countries.
- Five international centres produce the vaccines used every year, including one in Melbourne.
- While criticism of the level of outbreak for 2017 in Australia is mixed statistics showed that there were more reported cases this year than at any point since 2012
- Of the 217,559 cases of influenza reported in Australia up to October 2017 over half (101,793) were reported in New South Wales.
- Officials recognize an issue with how the influenza outbreak was handled in Australia this year, however they are divided on possible solutions to prevent a repeat in years to come.
With 2017 thought to have been a horror year for influenza in Australia, I thought I would research where our flu vaccines come from, how are they chosen and why has this year in particular been so bad?
A little about influenza
Flu, or more correctly known as influenza, is a respiratory virus which has similar symptoms to that of a common cold. The difference is the severity and quality of those symptoms. Surprisingly there are only two strains of influenza: A and B. However, within those two strains are combinations with varying protein chains of H and N. This is what gives the influenza virus the ability to mutate and evade eradication. Influenza can strike at any time of the year; however the colder months are more likely to see the spread of the virus. One possible explanation I heard a few years ago is that during the colder months people are more likely to congregate together indoors which would allow influenza to spread more readily. This could be due to the fact that influenza transmits via airborne means such as sneezing and coughing.
Globally the World Health Organization (WHO) estimates that between three to five million cases of severe influenza occur each year worldwide and of those 250,000 to 500,000 cases result in deaths. Australia specifically sees 18,000 hospitalizations for influenza annually with an average of 3,500 deaths. Influenza is also estimated to account for 10% of all yearly workplace absenteeism in Australia.
Worldwide vaccine efforts
As a virus you cannot cure it with antibiotics; once infected all you can do is wait it out. However, vaccines work by introducing a weak or dead strain of the virus into the body where antibodies can be produced which when confronted with the influenza virus will kill the virus before it takes hold of the host’s body and produce debilitating symptoms. The production of antibodies can take three to four months before fully effective so experts recommend having the flu vaccine early in the season to allow for immunity to develop.
The WHO has been responsible since 1952 for the monitoring of influenza and vaccine research through their Global Influenza Surveillance and Response System. Different influenza strains become more prominent from year to year, and strains can mutate. Therefore the WHO runs 142 monitoring centres in 112 countries. Five of those centres host World Health Organization Collaborating Centers for Reference and Research on Influenza:
- Atlanta, Georgia, USA (Centers for Disease Control and Prevention, CDC);
- London, United Kingdom (The Francis Crick Institute);
- Melbourne, Australia (Victoria Infectious Diseases Reference Laboratory);
- Tokyo, Japan (National Institute for Infectious Diseases); and
- Beijing, China (National Institute for Viral Disease Control and Prevention)
These five centres are also produce vaccines for the different influenza strains. Monitoring of influenza occurs year-round, however production of vaccines takes approximately six months and therefore decisions on which strains (usually three to four) are included are made half a year before the major flu season starts. The actual vaccine doses are then manufactured by private companies with the strains produced by the centres above.
The 2017 influenza season
So with all of the knowledge of influenza and the work of the WHO and CDC along with other scientific groups, what happened this year? Well that depends on who you ask. According to the Australian Department of Health the peak of the influenza season was mid-August of this year. The department did state that there appeared to be higher-than-usual numbers of cases being reported, however mitigated that fact by saying that testing was more readily used and could have contributed to the larger number of reports. Influenza A seems to be the dominant culprit this past season. The department’s report also goes on to say that they number of hospital admissions this season were ‘moderate’ compared to previous years, and that the vaccines given seem to have had a good effect.
NSW health minister Brad Hazzard would disagree with the federal department of health report. According to Minister Hazzard “I think at this stage what we got unfortunately was a vaccine, with the benefit of hindsight — and hindsight is a wonderful thing — that wasn’t quite up to it.” Peter Collingnon, executive director of ACT Pathology and a physician at the Canberra Hospital Infectious Diseases, went onto say that he felt the vaccine this year had very low efficacy for the A H(3) strain responsible for so many hospitalizations and deaths. Although the vaccine supplied to Australians was up to the global standard many patients were being seen by GPs with influenza despite being vaccinated.
According to the Immunisation Coalition in Australia as of the 24th of October 2017 there were 217,559 cases of influenza confirmed. Of those cases over half (101,793) were reported in New South Wales. The next highest rate was Queensland which only had 53,487. So in my state of New South Wales was by far the worst hit this past season. The reported number of cases nationwide, according to the Immunisation Coalition, in 2017 were significantly higher nationwide than at any point in the last five years.
So is this a trend, or just a one-off event? That is very hard to know. According to the information I read the experts are mixed. One possible suggestion is that our vaccine processes are out-dated and we need to re-think how vaccines are produced. Additionally, community hygiene practices could be reviewed to limit spread of influenza, particularly in peak times. What we do know is that influenza won’t be going away anytime soon. And at least for 2017 New South Wales bore the brunt of the outbreak.
As a member of the acute healthcare team I applaud every member of healthcare for their work and dedication during this flu season. Ask any person working in this industry, particularly in New South Wales, and they will tell you it was a very busy and trying time.
Until next time,
National Centre for Immunisation Research and Surveillance- Influenza fact sheet= http://www.ncirs.edu.au/assets/provider_resources/fact-sheets/influenza-FAQs.pdf
Centers for Disease Control and Prevention- CDC’s World Health Organization (WHO) Collaborating Center for Surveillance, Epidemiology and Control of Influenza= https://www.cdc.gov/flu/weekly/who-collaboration.htm
Centers for Disease Control and Prevention- Selecting Viruses for the Seasonal Influenza Vaccine= https://www.cdc.gov/flu/about/season/vaccine-selection.htm
World Health Organisation- Influenza (Seasonal) Fact sheet= http://www.who.int/mediacentre/factsheets/fs211/en/
Influenza Specialist Group- Influenza Fast Facts= http://www.isg.org.au/index.php/clinical-information/influenza-fast-facts-/
Australian Department of Health- Australian Influenza Surveillance Report and Activity Updates= http://www.health.gov.au/flureport
ABC news- Influenza: NSW Health Minister says current vaccine ‘not up to the job’ after deadly flu season= http://www.abc.net.au/news/2017-10-30/influenza-australia-deadly-year-prompts-calls-for-new-vaccine/9098598
Immunisation Coalition- Influenza Activity Surveillance 2017= http://www.immunisationcoalition.org.au/news-media/2017-statistics/