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The Pfizer COVID-19 vaccine passed a major hurdle after an FDA panel recommended approval today. Hugh Hastings/Getty Images
  • An FDA advisory committee voted to recommend emergency use authorization of the Pfizer/BioNTech COVID-19 vaccine.
  • The panel voted to recommend approval with 17 votes for approval, four against and one abstaining.
  • Some committee members voiced concerns that 16 and 17-year-olds could get the vaccine, despite few people in that age group taking part in the vaccine trials.

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An independent advisory committee for the Food and Drug Administration voted Thursday to recommend emergency approval of a COVID-19 vaccine developed by Pfizer and BioNTech.

The FDA isn’t required to follow the advice of the Vaccines and Related Biological Products Advisory Committee, although it usually does.

The panel voted to recommend approval with 17 votes for approval, four against and one abstaining.

The committee’s recommendation is for emergency use of the vaccine in people 16 years or older.

However, there was disagreement among the committee on whether 16- and 17-year-olds should be included, due to a lack of clinical trial data on this group.

It’s possible that the FDA could exclude this group if it moves forward with the emergency use authorization (EUA).

The agency could make a final decision on the EUA by next week, reported the Associated Press.

Last week, U.K. regulators approved the Pfizer/BioNTech vaccine for emergency use, with the first vaccinations occurring on Tuesday.

Canada’s regulatory agency approved the vaccine for emergency use on Wednesday.

Earlier in the week, the FDA released a briefing document for the advisory committee meeting. It includes detailed clinical trial data about the safety and efficacy of the vaccine.

The data confirmed that the vaccine protects people against symptomatic infection of the new coronavirus, SARS-CoV-2, with an average efficacy of 95 percent when measured at least 7 days after the second dose.

Dr. Reynold Panettieri Jr., vice chancellor for translational medicine and science director at Rutgers Institute for Translational Medicine and Science, said the efficacy results are “stunning and spectacular.”

“By and large, it was very impressive data that exceeded most expectations,” he said.

He pointed out that the vaccine also showed high efficacy in both older and younger people. The average efficacy in people over 55 years was 93.7 percent; for younger people it was 95.6 percent.

“That’s important because older adults are especially vulnerable to COVID-19,” he said.

Efficacy is a measure of how well a vaccine works during a clinical trial. Real-world effectiveness for a vaccine is often lower due to a number of factors.

The efficacy of the vaccine was also similarly high across other subgroups, except for participants who identified as multiracial and people who had a SARS-CoV-2 infection before the study.

There were too few people in these groups to interpret the data, the FDA scientists wrote in the briefing document.

The results presented by the FDA are based on data from about 38,000 people 16 years and older who took part in the Pfizer/BioNTech phase 3 clinical trial.

Participants were randomly assigned to receive either two doses of the vaccine about 3 weeks apart, or two doses of an inactive placebo on the same schedule.

The data also suggests that the vaccine may benefit people a little over 1 week after the first dose.

In the group that received the vaccine, COVID-19 cases started to plateau at about 10 days after the first dose, while cases in the placebo group continued to rise over the following weeks.

However, this doesn’t mean that a single dose would be sufficient.

Vaccine efficacy between the first and second dose was 52.4 percent on average, which is much lower than what was achieved after two doses.

In addition, most people received the second dose around 21 days after the first, which shortened the one-dose follow-up period.

So the results “cannot support a conclusion on the efficacy of a single dose of the vaccine,” cautioned the FDA in the briefing document.

One of the outstanding questions about COVID-19 vaccines is whether they can prevent severe illness rather than just symptomatic infection.

There are signs that the Pfizer/BioNTech vaccine may do just that. Of the 10 cases of severe illness in the trial, nine occurred in the placebo group, with one in the vaccine group.

The small number of severe cases, though, “limits the overall conclusions that can be drawn,” the FDA scientists wrote. “However, the case split does suggest protection from severe COVID-19 disease.”

Dr. Matthew Exline, a pulmonologist and medical director of the medical intensive care unit at The Ohio State University Wexner Medical Center, is excited at the possibility that the vaccine might prevent the kind of severe illness that he sees in the COVID-19 patients he treats.

“To see a vaccine that’s this effective, and one that can protect healthcare workers and our most vulnerable patients, provides a boost in confidence that we’ll be able to get through the pandemic,” he said.

The FDA scientists didn’t raise any significant concerns about the safety of the vaccine.

The most common side effects were pain at the injection site, fatigue, headache, muscle pain, chills, joint pain, and fever.

Most of these were mild or moderate, and lasted for about a day. However, a small number of people experienced one or more severe reactions.

“The side effects that were seen with the vaccine, which last for a day or two, seem to be a small price to pay to not experience even mild COVID-19,” Exline said.

However, he said hospitals may need to stagger the vaccination of its workers to avoid having many staff members dealing with side effects at the same time.

Another option, he said, is to vaccinate staff the day before they have a day off so they can recover at home.

Serious adverse events in the Pfizer/BioNTech trial were also rare, occurring in less than half a percent of people who received the vaccine.

One of these was Bell’s palsy, a condition that causes a temporary weakness or paralysis of the muscles in the face. Four people who received the vaccine developed this condition, with none in the placebo group.

However, the FDA said in its document that the frequency of this condition wasn’t above what would be seen in the general population.

The agency said it would recommend continued monitoring for Bell’s palsy in people who get vaccinated.

A small number of people also developed swollen lymph nodes, or lymphadenopathy: 64 cases in the vaccine group and six in the placebo group.

In large clinical trials such as this — especially when older adults and those with underlying health conditions are included — it’s not uncommon for some people to develop serious illness during the study. Many of those are unrelated to the vaccine.

On Wednesday, U.K. health authorities reported that two healthcare workers developed symptoms of an allergic reaction after receiving the vaccine the day before, reported CNN.

Both had a history of allergic reactions and carried an epinephrine autoinjector.

As a result, the U.K. regulatory agency advised that “people with a significant history of allergic reactions do not receive this vaccination.”

The Pfizer/BioNTech study protocol excluded people with a history of significant allergic reaction to a vaccine, medicine, or food due to the potential risks.

Scientists will continue to monitor people in the study for other potential safety concerns.

The FDA and the Centers for Disease Control and Prevention (CDC) also routinely monitor the safety of vaccines after emergency or regular approval.

For some groups, there isn’t enough data to know whether the vaccine will work for them.

The study didn’t enroll children under the age of 16, or pregnant or breastfeeding people, so researchers can’t know whether the vaccine is safe and effective for them.

Additional studies will be needed before the vaccine can be approved for these groups.

Likewise, while some immunocompromised people — including those living with HIV — took part in the phase 3 trial, researchers didn’t have enough data to determine whether the vaccine is safe for them.

Several questions remain about the vaccine, such as how long the protection lasts, whether it prevents asymptomatic infection, and whether people who have been vaccinated can pass the virus on to others.

Additional studies or longer follow-up of the current trial participants will be needed to answer these questions.

In the meantime, people will need to continue taking protective steps even after they’re vaccinated, especially if they’re in contact with people at high risk of severe COVID-19.

“We can’t dispense with masks and social distancing and good hygiene,” Panettieri said, “because we don’t know if the vaccine prevents transmission.”

Pfizer and BioNTech said they expect to be able to manufacture 50 million vaccine doses globally in 2020 and up to 1.3 billion doses in 2021.

The United States has ordered 100 million doses, enough to vaccinate 50 million people, reported Forbes.

Pfizer said earlier this week that it won’t be able to supply the United States with “substantial additional doses” of its COVID-19 vaccine until late June or July, according to The Washington Post.

Unlike other vaccines in development, the Pfizer/BioNTech vaccine has to be stored in an ultralow freezer, which not every hospital has access to.

“The challenge for the Pfizer vaccine will be the logistics around distribution because of the requirement of a minus 96-degree freezer for storage,” Panettieri said.

Exline said vaccination programs will also be hard-pressed to roll out the COVID-19 vaccine in a short time, adding that his hospital’s employee health group spends months getting ready for its annual flu vaccination campaign.

“The worst thing in the world,” he said, “would be if we get many doses of this vaccine, and then because we don’t have the logistics right, it sits in cold storage for weeks and doesn’t benefit either patients or providers.”