"Metformin, in the absence of contraindications or intolerability, should be the first-line agent to treat patients with type 2 diabetes," he said.

"If you don't have contraindications – such as a broken bone or blood clot or balance issues – it's certainly worth trying," Rao says.

But he points out that any child with a medical contraindication to receiving a vaccine can still receive an exemption to attend daycare or school.