A key advisory committee to the Food and Drug Administration unanimously recommended Thursday that booster shots be taken from ModernCovid-19 vaccine for people 65 and older and other Americans at risk. The vote was a critical step before the US can begin giving third vaccinations to some of the more than 69 million people who originally received this vaccine.

The non-binding decision of the Advisory Committee on Vaccines and Allied Biological Products of the FDA would extend the guidelines for Moderna with the third recordings of the FDA PfizerBioNTech Vaccination. These recordings were authorized less than a month ago to a wide range of Americans, including the elderly, adults with pre-existing medical conditions, and those who work or live in high-risk environments such as healthcare and grocery stores.

Although the agency has not always followed the advice of its committee, it often does. A final FDA decision on Moderna boosters could be made within days. A CDC Vaccines Advisory Committee is then expected to vote on the FDA’s proposal next week. If it recommends approval and the CDC endorses it, eligible Americans who completed their vaccinations at least six months ago could begin booster vaccinations immediately.

Booster vaccination has been a controversial issue for scientists – inside and outside of government – especially since many people in the US and other parts of the world have not yet received a single dose of a vaccine. The World Health Organization is urging wealthy countries to wait before distributing boosters, and some scientists say they are not convinced that most Americans need boosters right now.

When the FDA committee met last month, they opposed a proposal to distribute booster vaccines from Pfizer and BioNTech to the general public. Some committee members said at the time they were concerned that there wasn’t enough data to make a recommendation, while others argued that third shots should be restricted to specific groups.

After Moderna’s unanimous vote on Thursday, committee member Dr. Patrick Moore said the data the company submitted for approval of a booster was “not well explained,” adding that he was more on “gut instinct”.

“The data itself is not strong, but it is certainly going in a direction that supports this vote,” he said.

Some members said the boosters should prevent what they call breakthrough infections, which they believe are critical to protecting healthcare facilities from being overloaded, while other members said the third vaccinations should ensure high-risk patients don’t have serious illnesses. Some committee members also suggested that young people might not need boosters as the first few shots in these groups still persist.

Dr. Another member, Paul Offit, stressed that most people who received the first two doses of Moderna’s vaccine are still well protected and hopes the recommendation doesn’t send the “wrong message” to the public.

“If we’re trying to prevent the inevitable, which is a decline in neutralizing antibodies and an erosion of protection against mild or asymptomatic infections, that’s a high bar that we don’t hold any other vaccine by,” he told his colleagues.

The Biden government hopes the extra dose will provide long-term and permanent protection for the US population from serious illness, hospitalization, and death as the fast-paced Delta variant continues to spread.

Dr. Peter Marks, the FDA’s chief vaccine regulator, reached the committee Thursday before the vote, telling the panel of experts that the agency is promoting “all the different viewpoints” on the “complex and evolving” data.

“However, I would ask you, as we move forward, to do our best to focus our reflections on the science related to the proposal under consideration today and not on operational issues related to a booster campaign or related issues global vaccine justice. ”he added.

Moderna filed for FDA approval of a booster dose on September 1. The company said the results are based on a clinical study of about 170 adults, fewer than the 318 people screened for Pfizer’s booster vaccination. Moderna said a third half-dose shot – 50 micrograms – was safe for the first two injections and produced a strong immune response.

Once approved, the company plans to send a letter to health care providers explaining the dose difference for the third injection, said Dr. Jacqueline Miller, the company’s director of infection research, during a presentation Thursday.

The side effects of Moderna boosters were similar to those after the second dose, the company wrote in a document released Tuesday by the FDA. Most of the side effects were of minor severity and Moderna reported no cases of rare heart inflammation, myocarditis, or pericarditis in subjects for up to 29 days after receiving the booster.

Before recommending the third shots, the panel listened to several presentations, including from Israeli health officials, who began to offer boosters to their populations before many other countries. The country has mainly used Pfizer’s vaccine, but some Moderna boosters have been given.

Israel has given 3.7 million third vaccinations since its booster campaign began in late July, with about a third of the extra vaccinations going to people aged 60 and over, Sharon Alroy Price, director of public health at Israel’s Ministry of Health, told the panel.

She presented data suggesting that people receiving a booster dose are less likely to get infected with Covid or become seriously ill. She said officials have so far identified 17 cases of myocarditis or pericarditis after third doses.

“I think we can say, if we look at all of the data in Israel so far, that the use of booster doses has helped Israel reduce the infections and the severe cases,” she said.

– CNBC’s Robert Towey contributed to this report.