Remember the seasonal flu?

You might not consider disease to be a national security issue, but that depends on how you define national security.

A ‘disease’, by the way, is a disorder of structure or function in a human, animal or plant, especially one that produces specific symptoms.

In the past, strategists considered ‘national security’ to be about the survival of the nation-state, but these days it’s considered more broadly to be about the wellbeing of the nation-state.

So national security is not just about protection from threats posed by state and non-state actors, it can also include protection from infectious diseases and other health problems that can threaten a nation’s economic vitality and way of life.

The Covid-19 pandemic (‘pandemic’ meaning worldwide spread of a new disease) is the most obvious recent threat candidate because of its enormous impact.

A pandemic can become heavily politicised when it appears to have originated in a country that’s less affected by it than its major economic and strategic competitors. In the case of the Covid-19 virus, it’s thought to have originated in China, but was quickly and efficiently contained there, while its spread has had some of its most catastrophic impacts on China’s main competitor, the US.

Despite former president Donald Trump’s suggestion of nefarious intent by China, deliberately spreading a virus would be problematic given its unpredictability and likely spread to non-targeted populations. By contrast, for military use, a bacterium like anthrax could be launched into an enemy area then neutralised by the attacker’s advancing forces.

Covid-19 is in the process of being contained, but viruses will continue to challenge us. A medical doctor friend recently told me she nearly died two years ago from viral pneumonia. It was a reminder that viruses normally kill more Australians every year than Covid-19 has managed to do over the past 12 months.

Covid-19 had up until yesterday killed 910 Australians, of whom 820 were in Victoria and 54 in New South Wales. There have been 13 deaths in Tasmania and the other states and territories all have death tolls in single figures.

It’s hard to come by data on the number of virus-related deaths in Australia pre-Covid, other than those related to influenza and pneumonia. In 2010 there were 2,373 deaths, in 2014, 2,879 deaths and in 2019, 4,124 deaths.

Naturally occurring viruses can be more efficient killers than conflicts. Going back to the Spanish Flu, it killed around 15,000 Australians in 1919 alone; for comparison, 62,000 Australians died during World War I.

The seasonal flu is caused by the influenza virus. Flu viruses evolve freshly somewhere in East or Southeast Asia every year, spreading around the world over the next nine months before dying out. No particular country is the continual source of influenza viruses.

There are many different strains, and they can change every year. It’s different from the common cold. Many cold sufferers take time off work citing ‘flu’ as the reason, but influenza is a far more serious disease than the common cold. It can lead to bronchitis, croup, pneumonia, ear infections, heart and other organ damage, brain inflammation, brain damage and death.

The seasonal flu is easily spread from person to person, being primarily transmitted through contact with the droplets propelled into the air when an infected individual coughs, sneezes or talks.

It would be fair to estimate that, pre-Covid, at least 2,000 Australians a year suffered influenza-related deaths during the Australian flu season that runs from May to October.

In 2020, the Department of Health reported that (as of 18 December) there were 21,266 notifications of laboratory-confirmed influenza and 37 laboratory-confirmed, influenza-associated deaths in Australia. The low number last year is attributed to the precautions being taken to limit the spread of Covid-19.

The department notes ‘the impact of physical distancing measures, likely changes in health seeking behaviour of the community including access to alternative streams of acute respiratory infection specific health services and focussed testing for Covid-19 response activities’ were factors in the significant downturn.

The low numbers of deaths in 2020 also made it difficult to estimate the effectiveness of the flu vaccine, but in 2019 it was estimated to be 40–60% effective. This is, of course, well below the effectiveness of any of the approved Covid-19 vaccines.

The Pfizer vaccine has been shown to be 95% effective at preventing symptomatic Covid-19, while the efficacy of the AstraZeneca shot ranges between 62% and 90% ‘depending on dosage amount and time between doses’.

To complicate flu matters further, there are four types of virus: A, B, C and D.

Influenza A can infect humans and animals. In most cases, it’s associated with seasonal epidemics and global pandemics. It’s always changing, so it has various subtypes, including bird flu and swine flu.

Influenza B has two subtypes (Victoria and Yamagata), which occur for the most part only in humans and mutate slower, so it’s not a pandemic risk.

Influenza C infections generally cause mild illness and are not thought to cause human flu epidemics.

Influenza D viruses primarily affect cattle and are not known to infect or cause illness in humans.

Most Australians who die from flu, die from Influenza A (96% of deaths in 2019).

Influenza A viruses are classified by subtypes based on the properties of their Hemagglutinin (H) and Neuraminidase (N) surface proteins. There are 18 different HA subtypes and 11 different NA subtypes. Subtypes are named by combining the H and N numbers, to end up with something like A(H3N2).

This is probably more than you wanted to know about viruses, but the point is that it would be prudent and responsible from a national security perspective for all of us to have the annual flu shot and maintain the anti-virus precautions we’ve adopted for Covid-19.

The 2021 flu shot is now available but should not be administered within two weeks before or after a Covid-19-related vaccination.

The reality is that the seasonal flu and other viruses will continue to kill Australians long after Covid-19 has been contained globally.

This article was published by The Strategist.