• Measles is a serious, highly infectious viral illness. It’s spread through the air when an infected person coughs or sneezes. Sometimes even just breathing may be enough to spread the virus.
• It’s highly contagious: if you’re not immune to the virus and you come into contact with someone infected with measles, you have a 90 per cent chance of getting sick.
• A single infected person can typically make between 14–18 other people sick.
• If someone with measles enters a room and coughs, the virus can stay in the air for some time after that person leaves the room—sometimes for up to two hours.
• An infected person is contagious from the first day of symptoms. These typically don’t appear until about 10 days after exposure.

It’s not just the unvaccinated who pose a risk to public health: many people in Australia may be under-vaccinated without realising it.

Read more: Who is most at risk of measles?

At first, measles symptoms may be very similar to other viral infections, with people experiencing a fever, cough, runny nose, sore red eyes, and generally feeling sick and tired. A few days later, a nasty, spotty rash develops, starting from the face and progressing down the rest of the body. The rash lasts for 4–7 days.

Aside from being a miserable sickness to experience, roughly 10 per cent of measles cases involve complications. Some may be comparatively mild, such as diarrhoea or ear infections. Others, however, can be fatal: 1 in 20 people will develop pneumonia, one of the most common causes of death for young children affected by measles, while approximately 1 in 1000 people will develop encephalitis (inflammation of the brain) that can lead to permanent brain damage or death.

A measles-induced cough can easily and efficiently launch lots of viral particles into the air, where they can linger on surfaces for a long time (up to two hours, in some cases). This can be especially dangerous in aeroplane toilets, doctors’ waiting rooms or other places where many people share a small air space.

There is no specific treatment for measles. Instead, the aim is to manage the symptoms and reduce risk of complications.

The most effective way to keep yourself and your community safe from measles is through vaccination. In Australia, the MMR vaccine is typically given during childhood as two separate doses and provides protection against measles, mumps and rubella.

It’s safe and highly effective: if you’ve had two doses of the vaccine, it is 99 per cent effective at preventing measles infection. Not sure if you’ve had two doses? It’s safe to have another MMR vaccine if you don’t have evidence of a second dose to ensure you’ve got the best possible protection.