The US Centers for Disease Control and Prevention (CDC) on Monday announced an expanded call that all eligible Americans get a COVID-19 vaccine booster shot with the new omicron variant starting to spread. 

Earlier this month, the CDC already recommended that adults over the age of 50 along with those who have compromised immune systems should get a booster shot if it had been at least six months since they got the original two shots of the Moderna or Pfizer vaccine, or two months since they got the original single shot of the Johnson & Johnson vaccine.

The CDC originally said that anyone else over the age of 18 "may" get a booster shot.

But after four days of growing worry over the new omicron variant of COVID-19, which was discovered in southern African countries, the call for boosters became louder and more expansive to include the recommendation that all adults over the age of 18 "should" get a booster.

"The recent emergence of the omicron variant," said CDC Director Rochelle Walensky in a statement, "further emphasizes the importance of the vaccination, booster and prevention efforts needed to prevent against COVID-19."

Walensky mentioned data from South Africa that suggests omicron is easier to transmit than the delta variant and the race to figure out whether current vaccines are effective in fighting it.

A little over 70% of American adults were already fully vaccinated prior to the call for more booster shots.

"I strongly encourage the 47 million adults who are not yet vaccinated to get vaccinated as soon as possible," she said, "and to vaccinate the children and teens in their families as well because strong immunity will likely prevent serious illness."

The CDC will be keeping a close watch on when and where the omicron variant appears in the US. Walensky urged anyone who shows COVID-type symptoms to get tested as soon as possible so that it can be determined if omicron is the culprit.

"Increased testing will help us identify omicron quickly," she said./aa