U.S.-based Pfizer and its Germany-based partner BioNTech plan to give volunteers who received a placebo in its COVID-19 vaccine trial an option to receive a first dose of the vaccine by March 1, 2021.
“All participants aged 16 years and older who courageously volunteered to help make a difference during this pandemic have the option to receive the investigational vaccine while continuing to be part of the clinical trial,” the companies said on their website.
The U.S. Food and Drug Administration and a panel of its outside advisers have expressed concerns over Pfizer’s “unblinding” plan, saying it could make it harder to continue collecting data on safety and effectiveness needed to win full FDA approval of the vaccine.
The companies said that trial participants who received the placebo will have two doses of the vaccine reserved for them within the study.
Participants will be given the “Vaccine Transition Option,” the choice to learn whether they received the investigational vaccine or placebo. Those who find out they received the placebo will be given the option to receive the investigational vaccine while being able to stay in the study.
If they choose the vaccine option, they will receive the first dose by March 1, and the second dose about 21 days later, “and follow an updated study schedule that includes follow-up and illness visits.”
The Pfizer-BioNTech vaccine received FDA Emergency Use Authorization (EUA) on Dec. 11, 2020. At least five health care workers in Alaska experienced adverse reactions after getting the vaccine, the Anchorage Daily News reported. An Illinois hospital halted vaccinations after four workers suffered adverse reactions.
Britain’s medical regulator has said that anyone with a history of anaphylaxis, or severe allergic reactions to a medicine or food, should not be given the Pfizer-BioNTech COVID-19 vaccine.
The FDA has said that most Americans with allergies should be safe to receive the vaccine. It said that only people who have previously had severe allergic reactions to vaccines or ingredients in this particular vaccine should avoid getting the shot.
Dr. Peter Marks, director of the FDA’s Center for Biologics Evaluation and Research, said at a press conference in December 2020 that a chemical called polyethylene glycol (PEG), an ingredient in the vaccine, “could be the culprit.”
Pfizer said in a statement to news outlets in December that it was working to learn more details about the reported adverse reactions.
“We will closely monitor all reports suggestive of serious allergic reactions following vaccination and update labeling language if needed,” a Pfizer spokesperson said. “The prescribing information has a clear warning/precaution that appropriate medical treatment and supervision should always be readily available in case of a rare anaphylactic event following the administration of the vaccine.”
Drugmakers cannot be sued for monetary damages in court over injuries caused by vaccines or other countermeasures for COVID-19, according to an amendment to the PREP Act.
Common side effects of the vaccine include pain at the injection site, tiredness, and fever, according to the FDA.
“Of note, more people experienced these side effects after the second dose than after the first dose, so it is important for vaccination providers and recipients to expect that there may be some side effects after either dose, but even more so after the second dose,” the agency says on its website.
The Trump administration in late December purchased 100 million more doses of the Pfizer vaccine for delivery in 2021, bringing the total doses purchased by the government to 200 million, costing a total of $4 billion.
According to the FDA, the Pfizer-BioNTech COVID-19 vaccine contains messenger RNA (mRNA), which is genetic material.
“The vaccine contains a small piece of the SARS-CoV-2 virus’s mRNA that instructs cells in the body to make the virus’s distinctive ‘spike’ protein,” an FDA announcement reads. “When a person receives this vaccine, their body produces copies of the spike protein, which does not cause disease, but triggers the immune system to learn to react defensively, producing an immune response against SARS-CoV-2.”
Zachary Stieber and Reuters contributed to this report.