Centers for Disease Control and Prevention, or CDC, has approved the use of Pfizer and Moderna second booster shot for people 50 and older.

CDC Director Dr. Rochelle Walensky issued a statement allowing the second booster shots hours after the Food and Drug Administration authorized the second booster shot, according to an NBC News report.

Walensky said that boosters are safe and people over the age of 50 can now get an additional booster four-month after their prior dose.

The two agencies cleared the additional vaccine doses during a time that there is a concern about the spread of the extremely contagious Omicron subvariant, known as BA.2.

The current subvariant accounts for about 55 percent of the new cases in the United States based on the recent data from the CDC.

READ NEXT: Dr. Anthony Fauci Warns How Unvaccinated People Could Delay the End of COVID Pandemic in 2022 

Second Booster Shot

The CDC also recommended that all adults who received two doses of Johnson & Johnson's vaccine get third shots using Pfizer or Moderna, according to a CNBC News report.

Adults who received the J&J vaccine and the second shot of Pfizer of Moderna are not yet eligible for a third dose unless they are age 50 and older or they are immunocompromised.

The FDA and CDC made the decisions without calling meetings of their vaccine advisory committees, which rarely happens over the course of the pandemic.

Dr. Peter Marks, head of the FDA office responsible for vaccine safety and efficacy, said that the drug regulator did not call an advisory meeting as the decision was "relatively straightforward."

Marks said that the decision on the second booster shot is something with evidence from Israel, suggesting that getting additional doses, it can reduce the risk of hospitalization and death in older people.

Dr. Paul Offit, a committee member, said that it was a "sort of fait accompli." He also criticized the drug regulator for moving forward without holding an open meeting, where the public can hear experts weigh the data.

Pfizer and Moderna Booster Shots

In a large study, it suggested that those who received a second booster shot had 78 percent lower odds of death during the Omicron wave as compared to those who had a third shot at least four months earlier.

There were 232 total deaths out of around 234,000 people who only had three doses of the Pfizer-BioNTech vaccine, as compared to 92 deaths out of 328,000 people.

Other studies from the U.K. showed that antibody boost from a booster shot wanes very quickly, within a matter of weeks, according to a My NBC 5 News report.

Some experts feel that the United States should wait until there is a clear danger from a new wave of infections before rolling out fourth doses.

Both Pfizer and Moderna petitioned the FDA to allow an additional booster of their mRNA vaccines, according to a CNET News report.

Pfizer's request was intended for adults 65 and older, while Moderna has asked for approval for the use of all adults.

READ MORE: CDC Recommends Shorter COVID Isolation Period for Health Care Workers Amid Omicron Variant

This article is owned by Latin Post.

Written by: Mary Webber

WATCH: CDC and FDA authorize second COVID booster shot for some Americans - from CBS Chicago