Allergic reactions, cold chain discussed at FDA press conference about Pfizer-BioNTech COVID-19 vaccine

FDA Commissioner Stephen Hahn, M.D., and Peter Marks, M.D., Ph.D., the director of the Center for Biologics Evaluation and Research (CBER), held an online press conference this morning about the Pfizer-BioNTech vaccine and the emergency use authorization. Here are seven topics that came up during the questions and answers with reporters:

On allergic reactions. Marks said if people have had a history of allergic reactions, they should talk to their doctor. “But the vaccine, really, is one we are comfortable giving to patients who have had other allergic reactions besides those to a vaccine or one of its components.” Marks said the reactions seen among trial participants in Great Britain have not been seen in larger clinical datasets.” He said the CDC is helping make sure that all the sites where the vaccine is being administered will have the means to take care of an allergic reactions, including an epinephrine injector (Epipen), diphenhydramine (Benadryl) and potentially a steroid such as hydrocortisone.

Stephen Hahn

On pregnant women and people who are immunocompromised getting vaccinated. Marks said that there were not pregnant women in the trials to make any statement about the vaccine’s advisability for pregnant women. He said providers will need to consider vaccination for pregnant women and people who are immunocompromised on an individual basis. “Certainly Covid-19 in a pregnant woman is not a good thing so someone might decide that they would like to be vaccinated, but, again, that is not something we are recommending at that this time. That something we are leaving up to the individual,” Marks said.

On teenagers getting vaccinated. Marks defended the decision to approval the vaccine for use in people age 16 and older. He said the FDA was used to extrapolating to younger groups, and the known and potential benefits outweighed the known and potential risks. He said people in that age group don’t “get really sick with COVID-19 very often” (he acknowledged that it does happen) and noted that they can transmit the virus that causes COVID-19 quite easily even if they are asymptomatic. “Some of those 16- and 17-year-olds, at least that I know of are out there as checkout people or interacting with communities it may be wise to be able to vaccinate them.”

Peter Marks

On maintaining the cold chain. The Pfizer-BioNTech must be stored at minus 94 degrees Fahrenheit (minus 70 degrees Celsius). Marks noted, though, that after it is thawed it can be stored in regular refrigerator for a number of days. He expressed confidence in the logistics of keeping the vaccine at the temperatures so it will remain effective. “We have seen cold chains maintained in locations that are pretty rough, for instance with vaccination campaigns in Africa.”

On adverse events. Marks said the FDA has a list of 20 adverse events it will be on the lookout for. “If there are any signals in those, we will post those."

On people in the who were in the placebo group. Marks said he believes Pfizer plans to unblind the study, so those who received the placebo to ask to be potentially vaccinated. “Obviously right now in the United States we have to balance the amount of blinded data we received with the need to protect people from a pandemic that is taking thousands of lives daily.”

One dose instead of two. A questioner asked about some suggestions that the vaccine be distributed more broadly as a single dose rather than holding back some supply for the second dose. Marks emphasized the FDA review and emergency use authorization are based on a two-dose regimen. “It seems pretty foolhardy to conjecture that one dose might be OK without knowing, so at least from the FDA perspective we would be recommending that people complete the two-dose series so we actually that they are truly protected at the rate of approximately 95%.”

On pressure to approve vaccine. Hahn repeated his denial of the media reports the White House threatened to fire him if he didn’t approve the vaccine yesterday. “The representations in the press that I was threatened to be fired if we didn’t get it done by a certain date is inaccurate. So just want to put that on the record and I have been clear with that in our response to those press reports.”

Several times during the 40-minute press conference, Hahn spoke of maintaining scientific integrity while also working with a sense of urgency and he heaped praise on the FDA staff. “Again, our incredible team — heroic efforts, night and day worked to get this done and out the door and I think did a superb job and I really proud of their efforts because we understand the urgency of the situation. As Dr. Marks said, thousands of people are dying."