Contracting measles doesn't just make you feel lousy and put you at risk of potentially life-threatening complications, it can also cripple your immune system for years.
New research by Harvard University and the Wellcome Sanger Institute in the UK found the repercussions of measles last far longer than the time you're sick with the illness.
Two separate studies examining the immune systems of unvaccinated children before and after the measles infection found measles created a kind of "immune amnesia", leaving the body more vulnerable to future viral and bacterial infections.
New Zealand experts say these findings, published in Science Immunology and Science journals, emphasise the importance of widespread vaccination.
As well as wiping out protective antibodies leaving people more vulnerable to other infections, contracting measles can increase the severity of infections - like the flu - in the future, the researchers found.
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Each time you get a cold or an infection, your body forms antibodies to fight these bugs. Your immune system holds onto these antibodies.
The 'Mina' study of 77 children, found that unvaccinated children who had measles lost between 11 and 73 per cent of their antibody repertoire two months after infection.
This was not observed in infants vaccinated against measles, mumps and rubella (MMR), they found.
Researchers suggested vaccination against measles could prevent this immune "amnesia".
New Zealand is currently in the midst of the most significant measles outbreak it has seen in more than two decades.
A third of cases were so severe they required hospitalisation, and the majority were in unvaccinated people.
Vaccinologist Dr Helen Petousis-Harris said it was an "old urban-myth" that having measles made you stronger, instead it could weaken the system for up to five years.
When a person had measles, the virus infected some of the most important cells in the immune system and "wreaks havoc" during its stay, she said.
In just a few days it can infect up to 70 per cent of important immune memory cells.
"Ironically" the immune memory made against measles is "fantastic" - you're likely protected against getting the illness again - but you're increasingly vulnerable against a host of other illnesses, she said.
Petousis-Harris said the risks of not vaccinating against measles had "never been clearer", with these new studies highlighting the risk of ongoing health problems for years to come.
Dr Nikki Turner, from the Immunisation Advisory Centre, said the impacts of measles vaccination went "way beyond just measles protection".
The World Health Organisation reports that measles vaccination averted more than 21 million deaths between 2000 and 2017.
These findings suggest this could possibly be greater if indirect effects were counted, she said.
