What are your chances of suffering anaphylaxis, a severe allergic reaction, from the Covid-19 vaccine? Well, it may be significantly lower than your odds of getting badly injured by a toilet this year.
A new publication in the Centers for Disease Control and Prevention (CDC) Morbidity and Mortality Weekly Report (MMWR) indicates that the rate of anaphylaxis among those getting the Moderna Covid-19 vaccine has been approximately 2.5 cases per million doses administered. That is even lower than the rate reported so far for the Pfizer/BioNTech Covid-19 vaccine, which, as I described a week ago for Forbes, has been been around 11.1 per million doses administered.
Compare these numbers to 225 per million, which according to another CDC MMWR is the rate at which people suffered injuries from toilets in 2008. These were not just any injury from a toilet such as “I can’t feel my legs momentarily because I spent 15 minutes straight texting from the throne” toilet injuries. Instead, these were injuries that were bad enough to land people in the emergency room. This is a reminder that nothing is 100% safe and risk free, even something as comforting as the Porcelain Throne, the Poopatorium, the Oval Office, the House of Ease, or whatever you call that thing that you go to for all number one and number two occasions.
Now this toilet injury number may not seem directly comparable to the vaccine anaphylaxis numbers. After all, you may use the toilet or the texting throne anywhere from one to 50 times a day. (Note: if you are using the toilet closer to 50 times a day, contact your doctor.) This probably adds up to a much greater number than the number of Covid-19 vaccine doses that you will get over the course of a year. The Moderna Covid-19 vaccine, for example, is a two dose series, not a 365-dose series.
So perhaps, other numbers will help offer better perspective. According to a publication in the American Journal of Roentgenology, the risk for serious or severe reactions when getting contrast material used for imaging studies like a CT scan is between 0.02% (which 200 per million) and 0.4% (which is 4000 per million), depending on the type of contrast material. In a publication in the British Medical Bulletin, Hugh A Sampson, MD, a Professor of Pediatrics and Biomedical Sciences at The Mount Sinai School of Medicine, wrote that around 10.8 cases of anaphylaxis to food occur every 100,000 person-years. Oh, and by the way, if you are a run-of-the-mill-non-Leonardo-DiCaprio-dude your odds of dating a supermodel may be 11.3 out of one million, based on a article by Matt Rocheleau in the Boston Globe.
All of this further shows that two to 11 out of a million shouldn’t necessarily make you say “wow,” in the way Owen Wilson has said it in practically all of his movies. If someone were to tell you that you have a 2.5 out of a million chance of dating him or her, you probably wouldn’t respond by saying, “OK, so are you free this weekend?” Therefore, to date, the risk of anaphylaxis for either Covid-19 mRNA vaccine doesn’t seem to be high enough to raise alarms.
The reported odds of suffering anaphylaxis to the Moderna Covid-19 vaccine are based on the 10 cases of anaphylaxis that occurred after 4,041,396 first doses of the Moderna Covid-19 vaccine were administered from December 21, 2020 through January 10, 2021. The report was an analyses of data from the VAERS. VAERS is not what they called Captain Marvel before they found out her real name. Rather it stands for Vaccine Adverse Event Reporting System.
The CDC and the U.S. Food and Drug Administration (FDA) co-manage VAERS, which was established in 1990. Anyone who suffers or witnesses an adverse event after vaccination can report it to VAERS. Both healthcare professionals and vaccine manufacturers are required to report all such adverse events that come to their attention. Of course, you must report an adverse event to VAERS for it to be registered. VAERS is not like Facebook. It doesn’t watch what you do and collect information. Moreover, the adverse event needs to be legitimately connected to the vaccination. For example, feeling kind of nauseous after watching Keeping Up with Kardashians a week after getting vaccinated probably shouldn’t count as a vaccine-related adverse event.
Anaphylaxis is a severe allergic reaction that is potentially life-threatening. It results when your immune system overreacts to something like peanuts, bee stings, latex, or some type of medication, triggering the release of chemicals in your body. These then lead to typical signs of anaphylaxis such as a rash, rapid pulse, nausea, vomiting, the feeling that your throat is closing up, and difficulty breathing. This may throw you into shock with a major drop in your blood pressure. Anaphylaxis is a medical emergency. Usually, you’ll need something like epinephrine to reverse the reaction or risk dying, which is not a good thing.
Anaphylaxis is like a reaction to Justin Bieber’s song “Baby.” It tends to happen fairly soon after exposure or not at all. In fact, 9 of the 10 reported cases of anaphylaxis after the Moderna Covid-19 vaccine happened fairly quickly, within 15 minutes of vaccination, which is typical for anaphylaxis.
Keep in mind that just because anaphylaxis is life threatening doesn’t mean that it isn’t treatable. In fact, everyone who suffered anaphylaxis from the Moderna Covid-19 vaccine seemed to survive. The key is to recognize and treat anaphylaxis quickly.
Also, different people may have different risks of anaphylaxis. All but one of the people who had suffered anaphylaxis after the Moderna Covid-19 vaccine had had a history of allergies or allergic reactions to other drugs, radiographic contrast media, or food. In fact, five had suffered anaphylaxis previously to other things. So if you do have a history of allergies, you may want to talk to your doctor before getting the Covid-19 vaccine.
The CDC MMWR did report 43 allergic reactions that didn’t qualify as anaphylaxis and occurred within a day of receiving the Moderna Covid-19 vaccine. Of these over half (60%) were considered non-serious and consisted of symptoms such as itchiness, rashes, scratchiness in the mouth and throat, feeling that the throat is closing a bit, and respiratory symptoms. Most (73%) happened within 30 minutes of vaccination. Sixty percent of the people who had such reactions already had a history of allergies or allergic reactions to other foods or drugs.
Does all of this mean that the Moderna Covid-19 vaccine is safer than the Pfizer/BioNTech one? No, not necessarily. Overall, the number of reported anaphylaxis cases for both vaccines has been fairly small, 10 for the Moderna vaccine and 21 for the Pfizer/BioNTech vaccine so far. Thus, an 11 case difference in this case is not really that substantial and may not represent an actual difference between the vaccines. So allergic reactions is not a reason to choose one vaccine over another, if you do have the choice.
As I have written before, individual cases of anaphylaxis may sound alarming and make for striking headlines. Certainly such a case requires immediate attention. Don’t just say something like, “oh, there Brad goes again. Doing the whole anaphylaxis thing.” Nevertheless, cases here and there shouldn’t alone deter you from getting vaccination. Look at the actual overall risk based on the total number of doses that have been administered. And take proper precautions such as talking to your doctor if you do have a history of allergies and waiting while being observed by health care professionals for at least 15 minutes after getting vaccinated. But don’t fear the vaccine just because there’s a risk of something happening. After all, you don’t eye the toilet suspiciously every time you have to go to the bathroom, do you?