After receiving the Pfizer or Moderna COVID vaccine, you need to stick around for 15 minutes, per the Centers for Disease Control and Prevention (CDC), to watch for any adverse reactions, as there have been rare reports of anaphylaxis as a result of the vaccines. However, experts say people who receive the Johnson & Johnson injection likely won’t have to stay for observation after the shot, seeing as the FDA reported that there were no instances of anaphylaxis immediately following the administration of the Johnson & Johnson vaccine in the clinical trials.ae0fcc31ae342fd3a1346ebb1f342fcb CNN reported that during a briefing on Feb. 24, deputy director of the Maine CDC Nirav Shah, MD, said they “may remove some of the constraints that have been in place for safety reasons with the Moderna and the Pfizer vaccine. For example, the observation period.” And for more up-to-date COVID news delivered straight to your inbox, sign up for our daily newsletter. There have been a few reported cases of allergic reactions and anaphylaxis following injections with Pfizer and Moderna’s COVID vaccines. According to a January report from the CDC, there were 10 cases of anaphylaxis reported among more than 4 million administered shots of Moderna between December and January, which is a 0.00025 percent rate. The CDC also reported that of 1.9 million shots of Pfizer administered in December, there were 21 cases of anaphylaxis, according to another January study, which is a 0.0011 percent rate. To see what you can finally do again after your shot, check out Dr. Fauci Just Confirmed You Can Do This After Getting Vaccinated. The Johnson & Johnson vaccine is created using an adenoviral vector, where a tiny piece of genetic material from COVID is inserted into a weakened version of the common cold virus (adenovirus), which was altered so it can enter cells but not reproduce inside of them, explains Prevention. After a lot of traveling throughout the cell, the adenovirus teaches your immune system to make antibodies to address the perceived threat. When your body comes in contact with the real virus later on, it will then be able to fight it more efficiently. On the other hand, Pfizer and Moderna’s shots are mRNA vaccines, which means they don’t contain any live virus and instead, deliver instructions to the cell to make a tiny piece of the coronavirus spike protein, which then prepares the immune system to recognize the virus in the future, explains the CDC. The mRNA vaccines use a lipid-based nanoparticle that prevents the mRNA from degrading and aids in delivery, according to a Feb. 18 study from The New England Journal of Medicine. This nanoparticle is stabilized by polyethylene glycol (PEG), which might be at the root of many of the anaphylaxis cases. Phillip Santangelo, PhD, a professor of biomedical engineering, told NBC affiliate 11 Alive that Johnson & Johnson could be a safer option for people at risk of anaphylaxis because the vaccine is devoid of PEG and lipids that are can cause allergic reactions. To see if you should hold off for this shot, check out This Is Who Should Wait for the Johnson & Johnson Vaccine, Experts Say. Because of these isolated incidences of anaphylaxis, the CDC recommends an observation period of 15 minutes following vaccination with mRNA COVID-19 vaccines like Pfizer and Moderna. However, “persons with a history of an immediate allergic reaction of any severity to a vaccine or injectable therapy and persons with a history of anaphylaxis due to any cause should be observed for 30 minutes,” the agency adds. Without any evidence of potential anaphylactic reactions, people who get the Johnson & Johnson vaccine should be able to skip out on any observation period, as Shah predicted. To see what you should steer clear of before and after your shot, check out The CDC Says Don’t Do This Within 2 Weeks of Your COVID Vaccine.
