We've heard opinions from scientists, specialists, politicians, celebrities, quacks, ill-informed Facebook friends, near enough everyone has a firm opinion one way or another...but the pro-vaccination movement have gone and pulled out the big guns.

Elmo has joined the fight.

In a video by Sesame Street in collaboration with U.S. Department of Health & Human Services and the Daily Dot, US Surgeon General Vivek Murthy drops by to explain to Elmo just why vaccinations are so important.