The agency has authorized a fourth COVID vaccine shot from Pfizer and Moderna, a decision that was immediately backed by the CDC but was made without consulting the committees of independent vaccine experts.

Health regulators with the Food and Drug Administration (FDA) announced on Tuesday that they have authorized fourth COVID vaccine doses for older adults after concerns over a more contagious version of the Omicron variant would cause another wave in cases in the U.S. like in Europe and China.

The FDA has approved a fourth dose of the Pfizer and Moderna COVID vaccines for individuals aged 50 and older and a fifth dose for certain younger people with compromised immune systems. Reports said that those aged 12 and above with weakened immune systems may get a fifth dose of Pfizer's COVID vaccine, while those 18 and older with the same condition can take a fifth dose of Moderna.

According to CNBC, the Centers for Disease Control and Prevention (CDC) quickly backed the FDA's approval of the second Pfizer and Moderna booster shots for people 50 and older. The agency also recommended those who received two doses of the Johnson & Johnson COVID vaccine to get a third dose of Pfizer or Moderna.

"Current evidence suggests some waning of protection over time against serious outcomes from COVID-19 in older and immunocompromised individuals," Dr. Peter Marks, director of the FDA's Center for Biologics Evaluation and Research, explained, as per the Gateway Pundit. "Based on an analysis of emerging data, a second booster dose of either the Pfizer-BioNTech or Moderna COVID-19 vaccine could help increase protection levels for these higher-risk individuals."

Dr. Marks added that the data showed that one booster dose was "critical in helping to protect all adults from the potentially severe outcomes of COVID-19." He "strongly encouraged" adults to get their third shot of the COVID vaccine. All boosters must be administered at least four months following their last shot of the COVID vaccine.

However, the FDA and CDC made the decision to approve the second Pfizer and Moderna booster without meeting with their independent vaccine advisory committees, an unusual move as these agencies had frequently consulted the committees with regards to the vaccines during the pandemic. 

The FDA's advisory committee on vaccines is set to meet on April 6 to determine how to go about booster shots in the future in the U.S. The meeting is expected to result in a decision over specific recommendations for boosters moving forward.

Health experts have disagreed on the need for a fourth vaccine dose. In general, they are for providing a fourth dose for the elderly and those who have a compromised immune system and opposed to booster shots for younger people, who are less susceptible to severe COVID.

Committee member Dr. Paul Offit criticized the FDA for approving the second Pfizer and Moderna shots for people 50 and older without conducting a meeting where the general public can hear experts' opinions on the data and make recommendations to the FDA for how to move forward.

"It's just sort of fait accompli," Dr. Offit remarked. "So is this the way it works? We talk endlessly about how we follow the science - it doesn't seem to work out that way."