FDA Says Pfizer Vaccine Meets Success Criteria

As we get closer to defeating the coronavirus pandemic, the U.S. Food and Drug Administration is releasing new information regarding the Pfizer vaccine, which is already being distributed by the United Kingdom. In a safety report, the FDA says the drug developed by Pfizer and its partner BioNTech is both safe and effective against COVID-19.

This is in the lead-up to the FDA’s Vaccine Advisory Committee Meeting on December 10th when a group of epidemiologists and infectious disease experts will convene to discuss whether the drug should be granted an emergency use authorization (EUA).

Based on the new safety report released by the FDA, it’s looking more likely that the Pfizer vaccine will receive an EUA, which means the first doses will start going out in the next few weeks.

A Positive Sign for the Pfizer Vaccine

On Tuesday morning, the FDA released its review of the vaccine in a briefing document, which will be the basis for discussion during the Vaccine Advisory Committee meeting. The report shows that the drug is both safe and effective after going through a long series of clinical trials involving tens of thousands of patients.

Right behind Pfizer, Moderna has also issued promising safety data regarding its vaccine. The FDA Vaccine Advisory Committee will meet on December 17th to discuss the merits of the Moderna vaccine, which could also be made available by the end of the year, if approved for an EUA.

Both the Pfizer and Moderna vaccines use what’s known as messenger RNA to prevent an infection from taking root in the body. The drug contains a special genetic code that contains instructions for defeating the virus. Our bodies will then make a specific protein, the same spike protein that’s attached to the coronavirus. This new protein will create antibodies that will fight off infection, thus preventing serious illness and reducing the chances of infected individuals passing the virus onto others.

This isn’t the same as your yearly flu shot. When getting vaccinated for the flu, the body receives a weakened form of the virus, so it can produce antibodies and protect itself from possible infection. The vaccines developed by Pfizer and Moderna do not contain a weakened form of the coronavirus, just a special form of instructions for defeating it. That means it is impossible to get the virus from taking the vaccine.

The messenger RNA formula has its benefits, according to Dr. Hana El Sahly, who is overseeing the ongoing clinical trial for Moderna’s vaccine candidate. Instead of having to grow the virus in a lab and inoculate it before putting it in a drug, as is the case with the yearly flu shot, messenger RNA can be produced quickly.

“The attractiveness of it is the speed with which it can be manufactured once we know the sequence of the virus,” said Dr. Hana El Sahly.

In case you were wondering, the first shot only gives patients partial protection from the virus.

“The second dose is absolutely critical to bring the majority of individuals who would receive this vaccine above threshold levels needed in terms of protection,” says Deborah Fuller, a microbiologist and vaccine developer at the University of Washington.

What About Side Effects?

Thousands of people in the U.S. have already received the vaccine as part of the clinical trial process. Both the Pfizer and Moderna vaccines must be administered in two doses, with the second shot coming three weeks after the first. Some have reported side effects after getting the second shot, but they tend to be mild or resolve themselves after a day or two.

Common side effects after getting the second shot including headaches, muscle stiffness, and fatigue.

In the new safety report, the FDA acknowledges that these types of side effects are common; however, there are “no specific safety concerns identified that would preclude issuance of an EUA.”

Most vaccines come with side effects, so this isn’t anything new. Preliminary safety data shows these effects can be more pronounced in people under the age of 55.

However, serious adverse reactions tend to be rare. Among people aged 18 to 55 who received the Pfizer vaccine, just 4.6% reported severe fatigue after getting their second injection, and 3.2% had severe headaches. For those under the age of 55 who participated in the clinical trial, 2.8% reported severe fatigue, 0.5% experienced severe headaches after the second dose, and 10.9% had a fever.

Experts say most people won’t experience a severe allergic reaction after taking the drug; however, health officials in the U.K. recently told doctors that anyone with a history of significant allergic reactions to a vaccine, medicine, or food shouldn’t receive the Pfizer-BioNTech vaccine, as it may lead to an allergic reaction.

Based on the latest safety data and historical precedent, the Pfizer vaccine is unlikely to cause long-term side-effects. Those that have experienced side-effects say they cleared up within just a few days. Some with severe fever, headache, and muscle stiffness received medications and their symptoms cleared up quickly.

The safety report also shows that these trends hold up regardless of the patient’s age, race, ethnicity, or background, which should help put the concerns of your patients at ease.

Federal regulators have no shortage of safety data to draw from. We will get the FDA’s final verdict on the drug tomorrow, December 10th. If it gets the green light, the first doses will be headed out in the U.S. soon.