Vaccination has been a highly controversial topic in recent years, resulting in a slew of “Anti-Vaxxers” and the School Vaccination Law in California, which mandates that children that attend public school must be vaccinated.

British Columbia’s ImmunizeBC and agency Rethink Vancouver have teamed up to create a unique mailing campaign to promote vaccination, appropriately called “Viral”. The trailer for the campaign states that “Measles is one of the most contagious diseases on the planet, but as you know, it’s making a comeback.”

However, the kicker is the actual mailing campaign: when exposed to sunlight, the UV-responsive ink on the paper appears suddenly in a rash of bright red spots, reminiscent of–you guessed it–measles. The alarming card shows how fast measles can spread, and reminds recipients that “not vaccinating your children puts us all at risk”.

This comes after particularly alarming reports of measles spreading throughout the United States, including an outbreak at Disneyland, and reminds parents to vaccinate their children or risk them being a public health hazard.

What Sparks Our Fire: Ingenious campaigns that post important public health reminders