SPRINGFIELD, Mass. (WWLP) – COVID-19 cases are up 10 percent nationwide, as the World Health Organization announces a change in mask guidance.

The spread of the delta variant caused the World Health Organization to call on vaccinated people to wear masks, but you have to keep in mind, most other countries don’t have nearly as many vaccines.

The uptick in cases is being linked to the delta variant, which originated in India. It is becoming more widespread in the United States, and unvaccinated people are particularly vulnerable, especially without a mask on. According to the World Health Organization, vaccinated people should also be wearing masks, contrary to the CDC’s guidance.

Baystate Health’s Dr. Megan Gallagher explains why the two health agencies’ mask guidance is different.

Dr. Megan Gallagher said, “It’s important to remember the world health organization is providing guidance for the whole world. In much of the world, there is not nearly the degree of vaccine availably or uptick like here in the United States.”

Dr. Gallagher said even though the vaccine is our best protection against the virus, it’s not 100 percent, so mask-wearing is still a good idea if you’re going to be in a crowded setting. Also, people with health conditions that compromise their immune system, may not respond as well to the COVID vaccine.