One dose of a two-dose COVID-19 vaccine will provide some protection, but not nearly as much as if you had both doses.

It's why experts recommend getting fully vaccinated. They say it's particularly important in areas where worrisome variants like the delta are spreading.

The COVID-19 vaccines being distributed were developed to target the original version of the virus.

While they seem to protect against the newer variants, there's a concern the shots might eventually lose their effectiveness.

Health officials are also worried about countries that don’t have enough supply to distribute second doses within the recommended time frame.