Will the coronavirus vaccine hurt?

Originally published on Nautilus Magazine on December 3, 2020, but is now offline. Archived on Wayback Machine.

One of the most common things physicians warn you about after being administered any vaccine is that you may experience soreness afterward, and if you do, you can take a painkiller to help lessen the discomfort. But will the coronavirus vaccine hurt? According to early reports, the leading COVID-19 vaccines in development share plenty of qualities with other vaccines you may already be accustomed to, and one of the things you ought to expect is some pain.

Pfizer and Moderna, the two companies currently approved by the FDA to offer vaccines, have about a 95% efficacy. According to Kaiser Health News, scientists say the vaccines causing a myriad of flu-like side effects that may include sore arms, muscle aches, and a fever that could potentially last for days, possibly putting patients out of commission from work or school.

Of the side effects described by participants in Moderna’s coronavirus vaccine trials, the most common complaint was that it hurt—2.7% of participants experienced injection site pain after being administered the first dose. More trial participants recorded severe side effects after being given the second dose: fatigue (9.7%), muscle pain (8.9%), joint aches (5.2%), headache (4.5%), pain at the injection site (4.1%), and redness around the injection site (2%). For the Pfizer vaccine, trial participants reported fatigue (3.8%) and headache (2%) at significantly lower numbers.

Some scientists admit that these results of severe coronavirus vaccine reactions may be higher than what most patients are used to, that it might hurt more than normal. “This is higher reactogenicity than is ordinarily seen with most flu vaccines, even the high-dose ones,” Arnold Monto, an epidemiologist at the University of Michigan, told Science magazine. 

Ian Haydon, a participant in Moderna’s first human trial, reportedly received the highest dose of the vaccine and experienced all the known severe side effects, as well as chills and nausea. He also vomited and fainted 12 hours after receiving his second shot in May, but all symptoms receded around 24 hours after they first started. Despite this, Haydon told Science that it was worth going through all that just to get back to what everyday life was like pre-COVID-19. “For me, this was a rough day,” he said. “But if you compare it to what COVID can do, I think it really pales in comparison.”

Here’s another first-hand view from an ER doctor of what it’s like to get the vaccine.

How do vaccines work, and why do they hurt?

By design, vaccines contain a part of the very thing that causes the disease. An organism that causes illness is called a pathogen, which is made of several subparts that are unique to that specific pathogen and the disease it causes. One of these subparts is called an antigen, which essentially causes the body to produce antibodies that will eventually fight off the infection. When the body is exposed to an antigen for the first time, it takes the immune system time to form a reaction and to produce antibodies that are specifically designed for that antigen.

Vaccines contain a weakened or inactive part of a particular antigen that will trigger the immune system into antibody production. It will not cause the disease, but it acts as sort of a trial run for the antibodies produced so that its response to the actual pathogen will be much faster should the person be exposed to it in the future.

Side effects are common in most vaccines. According to Inverse, the reason the coronavirus vaccine being developed by Moderna and Pfizer are causing these particular side effects is because of the way the human body’s immune system is reacting to the vaccine’s makeup. Both products are mRNA vaccines. Those are composed of “the genetic instructions the body needs to make a piece of the coronavirus,” which is enveloped in a fatty encasement because it is unstable by itself. “This sort of complex lipid [fat] encasement can be reactogenic, meaning it can cause these kinds of side effects including low-grade fever and the side effects associated with fever, [like] headache, muscle aches, fatigue, chills,” Paul Offit, director of the Vaccine Education Center at Children’s Hospital of Philadelphia, told Inverse. “It doesn’t usually last more than a day or two.”

Offit believes that despite reports of the hurt associated with the coronavirus vaccine, people who understand the importance of getting the two-dose shots would not be deterred by it, simply because it’s not the first instance of painful medication. Shingrix—an FDA-approved vaccine against shingles, a painful red rash caused by a reactivated chickenpox virus—can reportedly cause local pain, redness, and swelling. In severe instances, it can also cause muscle aches, fatigue, headaches, shivering, fever, and stomach issues. People, however, would still rather get the vaccine than have to face the actual illness.

“People get shingles vaccines knowing that they might miss a day of work, because shingles is one of the worst pains in medicine, and this is a virus that has brought us to our knees,” Offit shared with Business Insider. “People are usually pretty good at getting their second dose of shingles vaccine so it bodes well for people coming back to get their second dose of [the coronavirus] vaccine,” he continued.

People still need convincing to get the COVID-19 vaccine

According to a Gallup poll, only half of Americans said they’d be willing to get the COVID-19 vaccine, as of mid-October, but by mid-December, that number had risen to about 70%. While there could be a myriad of reasons for the hesitancy, part of it is surely the lack of information and transparency on how it actually works and the accompanying data of trial results that outline what people need to expect after getting it.

“We really need to make patients aware that this is not going to be a walk in the park,” Dr. Sandra Fryhofer of the American Medical Association said during a virtual meeting with the Advisory Committee on Immunization Practices, an outside group of medical experts that advise the CDC. “They are going to know they had a vaccine. They are probably not going to feel wonderful. But they’ve got to come back for that second dose.”

Other ways that could change the way people view the coronavirus vaccine is by using more encouraging language, such as saying “response” rather than “adverse reaction,” as suggested by Patsy Stinchfield, a Children’s Minnesota nurse practitioner. Equally important is how public health experts will explain the known coronavirus vaccine side effects, including the hurt it might cause. “There’s evidence that suggests that if you frame pain as a proxy of effectiveness, it’s helpful,” Saad Omer, director of the Yale Institute for Global Health, told Kaiser Health News. “If it’s hurting a little, it’s working.”

Sources: NBC News, Business Insider, Science Magazine, WHO, Inverse, Gallup, CNBC, Kaiser Health News