PORTLAND, Ore. (KOIN) – On Saturday, the Washington Department of Health recommended a third dose of the Pfizer-BioNTech and Moderna COVID-19 vaccines for people with weakened immune systems.

The recommendation comes just days after the U.S. Food and Drug Administration announced that immunocompromised Americans – not the general public – can get a third shot of one of the mRNA vaccines.

Certain medications, diseases and organ transplants can make it more difficult for some people to develop the same level of protection as their unaffected counterparts, according to a list of conditions compiled by the CDC.

Health officials said the third dose is not considered a booster, but rather an additional dose for some who did not develop adequate immunities from the initial two-dose series.

“A third dose of Pfizer or Moderna will provide those who need it extra protection and help shield some of our most vulnerable from the highly contagious delta variant,” said Washington Secretary of Health Umair Shah. “Science continues to show vaccines are the best tool we have to protect our communities and slow the spread of COVID-19.”

Although authorized vaccines have proven to be more than 90% effective in protecting against most variants, officials said, emerging data suggests people with moderately to severely compromised immune systems do not always build the same level of immunity compared to people who are not immunocompromised.

A person receiving a third dose should get it at least 28 days after dose two. When possible, the individual should receive the same vaccine as the first two doses, but may receive the other mRNA vaccine brand if the other vaccine is not available.

The Washington Department of Health said it does not recommend an additional dose for people who received the Johnson & Johnson vaccine. People with adequate immune systems should not receive an additional dose of any COVID-19 vaccine, officials said.