PORTLAND, Ore. (KOIN) — There was a long line of parents bringing their younger kids for a COVID vaccine shot at David Douglas High School in a clinic run by Multnomah County on Monday. But now that booster shots are approved for everyone over the age of 18, you might be wondering if you need to get one now.

The CDC now says those over 50 should get a booster since immunity drops over time. But they also said those under 50 can get a booster.

Dr. Bill Messer, an infectious disease expert at OHSU, told KOIN 6 News a younger person’s immunity may be stronger than an older person’s and they could wait. But the risk of a breakthrough case is higher without the booster.

Messer also supports the idea that getting a booster of either the Moderna or Pfizer vaccine is a good idea.

Pfizer on Monday said its vaccine is 100% effective in protecting kids 12-15, based on a study of more than 2000 people in that age bracket. It’s also 90% effective for kids between 5-11.

As for Thanksgiving, Dr. Anthony Fauci said if your guests are vaccinated, go ahead and have a lovely day.

“If you’re vaccinated, and hopefully you’ll be boosted, too, and your family is, you can enjoy a typical Thanksgiving,” indoors and without masks, White House chief medical adviser Dr. Anthony Fauci said on ABC’s “This Week.”

But, Fauci added, “The thing we are concerned about is the people who are not vaccinated.”