They're known as immunization registries and they keep track of children's — and increasingly adults' — immunizations.Vaccines against the SARS-CoV-2 virus that causes the disease COVID-19 are expected to require two doses, given a month or so apart, and come in several types. That's a recipe for disaster without a central repository to know who got what vaccine and when. 

Imagine this scenario: You get your first coronavirus shot at a local health department clinic. A month later, when it's time for your follow-up, you go to your doctor or a local pharmacy.

"They'll need to know which one you got, when you got it and double-check when you're due for your second dose," said Dr. Kelly Moore, associate director of immunization education with the Immunization Action Coalition.