The Flu Explained

What is ‘the flu’?

We often get questions about ‘the flu’. Many people use the term to describe a winter cold. When we use it, we are referring to the influenza virus. There are two main types of the influenza virus that affects humans: A and B. Within influenza type A, two subtypes are common: A/H1N1 and A/H3N2. Within influenza B, there are two lineages: Victoria and Yamagata. 

How do I catch the flu?

Influenza viruses are mainly spread by droplets made when an infected person coughs or sneezes. It can also be spread through touching surfaces where infected droplets have landed. The incubation period is usually 1-3 days.

How long am I infectious for?

People with influenza can be infectious from the day before their symptoms start. Adults are most infections in the first 3-5 days of their illness. Children remain infectious for 7-10 days, and people with weakened immune systems may be infectious for longer.

What is the treatment for the flu?

Generally speaking, bed rest and symptomatic treatment is what we do. Specific influenza antiviral medications can reduce the severity and the duration of the illness if taken soon enough after the onset of symptoms. We recommend people stay isolated until the symptoms resolve.

What are the complications of the flu?

Most people who get the flu will recover within a couple of weeks. Common moderate complications include ear infections and sinusitis.  There are serious complications such as pneumonia, or the virus causing inflammation of organs such as the heart (myocarditis) and the brain (encephalitis). These complications are rare but can be life-threatening.

Should I be immunised?

The flu vaccine  is recommended for anyone over 6 months of age. It is strongly recommended for children, pregnant women, the elderly, people over the age of 65, Aboriginal and Torres Strait Islander people over the age of 15, health care workers and people with certain conditions.

How effective is the influenza vaccine?

In general, the vaccine effectiveness has been found to vary between 40-60%. This actually means that on average, a vaccinated person is 40-60% less likely to experience the outcome being measured (e.g attending a doctor for it, or getting hospitalised) than an unvaccinated person. 

How bad is the flu this year?

Currently, influenza and influenza-like illness activity are high for this time of year compared to previous years. In the year to date, there have been over 93,000 lab-confirmed cases nationally. In the last fortnight, there have been over 19,000 (of which approx 7000 of these cases were from NSW).  This is substantially higher when you compare the same period in the last five years.

Lastly…. can the flu vaccine give you the flu?

No!!! The flu vaccine is an inactivated vaccine (ie you are not getting ‘a little bit of the virus’). It does cause an immune response which means you may feel a bit achey for a few days, with a sore arm. But it can’t give you the flu.