The COVID-19 vaccine is here — What to know about side effects
From the time they were first developed, vaccines have prevented countless cases of disease and disability and have saved millions of lives. Ensuring the safety and effectiveness of these vaccines is among the top priorities of the U.S. Food and Drug Administration (FDA) and U.S. Centers for Disease Control and Prevention (CDC).
Bringing this same hope against the deadly COVID-19 pandemic are new vaccines from Pfizer and Moderna, now being distributed to health care employees and other high-risk essential workers.
The FDA granted Emergency Use Authorizations (EUA) after the vaccines were shown to be safe and effective, based on data from the manufacturers and the findings from clinical trials involving some 74,000 people.
The data show that the demonstrated benefits and potential risks of these vaccines outweigh the known harms and potential complications of becoming infected with COVID-19.
Like any vaccine, these new vaccines can cause some minor side effects.
Most reported side effects are minor
Clay Dunagan, MD, BJC HealthCare chief clinical officer and infectious disease specialist, says both the Moderna and Pfizer vaccines can cause common vaccine side effects, most lasting a day or two.
"From the early clinical trials, very few major problems arose,” Dr. Dunagan says. “Most commonly seen were the usual immediate effects or reactions from a vaccination, such as soreness at the injection site or feeling a little ‘under the weather.’
“Other reported side effects include fever, headaches, fatigue, and muscle and body aches in the days immediately following vaccination. Some have felt ill enough to stay home for a day or two. But there are no indications that there will be any substantial problems with people tolerating the vaccine.”
In its review of clinical trial data on the Pfizer COVID-19 vaccine, the FDA noted that more people experienced side effects after the second dose than after the first dose, and that providers and recipients should expect that there may be some side effects after either dose.
Side effects can be viewed as validation that the vaccine is working. The COVID-19 vaccine is designed to prepare the body to fight coronavirus in the future. The commonly reported side effects are generally the result of a normal, healthy immune system responding to the vaccine. Not everyone experiences a reaction. In fact, most people do not. Those who don’t have side effects can expect to receive the same level of protection from the vaccine.
The CDC projects that only 2% of those who receive the vaccine will have side effects significant enough to interfere with their usual daily activities. Among BJC HealthCare employees, only about 1% of those vaccinated have reported some minor side effects so far. Tylenol or ibuprofen may be taken after vaccination to help with any minor symptoms. Those who experience unusual or persisting symptoms should consult their primary care provider.
The number of severe allergic reactions reported has been about one out of every 100,000 people vaccinated, and those have occurred primarily in people who were known to have severe allergies.
Any serious reactions will be monitored closely, Dr. Dunagan adds. “There will be very intense scrutiny of vaccine recipients over time, and if any questions arise about safety or long-term concerns, of course, there will be immediate attention to it,” he says. “But right now, we have simply no indication there will be any problems with people taking the vaccine.”
More on COVID-19 vaccine safety and side effects
With a new vaccine, it’s not unusual for people to have specific questions about the safety and potential side effects of the COVID-19 vaccine — especially with regard to certain health conditions. Here are a few of those questions, with answers courtesy of BJC HealthCare, the CDC and the FDA:
Can I get COVID-19 from the vaccine?
You cannot get COVID-19 from the Pfizer and Moderna vaccines. Neither contain any live virus or infectious matter. They are designed to cause your body to make copies of a harmless piece of the coronavirus to develop an immune response, so you will not, and cannot, get COVID-19 from the vaccine.
Should I get the vaccine if I have allergies?
Regarding allergic reactions to the vaccines, the FDA notes that any vaccine or medication has the potential to cause severe allergic reaction. If you have had prior severe allergic reactions to other vaccines or if you have had reactions to the ingredients of the Pfizer coronavirus vaccine or the Moderna coronavirus vaccine, the FDA currently recommends that you avoid these vaccines.
If you have allergies, especially severe ones that require you to carry an EpiPen, discuss the COVID-19 vaccine with your doctor, who can assess your risk and provide more information on if and how you can get vaccinated safely.
Should I get the vaccine if I have underlying health conditions?
Those with underlying conditions such as diabetes and heart disease are at high risk for experiencing complications from COVID-19. So, it is even more critical that they receive the vaccine. If you have concerns, consult with the doctor who is helping you manage the condition.
Should I get the vaccine if I have underlying health conditions?
People with suppressed immune systems, as a result of cancer treatment or autoimmune disease for example, can safely get the COVID-19 vaccine since it doesn’t contain a live virus. Again, you should talk to your doctor if you have concerns.
Should I get the vaccine if I’m pregnant or breastfeeding?
The CDC says it’s OK for pregnant women to get the vaccine, but advises they talk to their doctor if they are concerned about the risks versus the benefits of the vaccine. Pregnant women who contract the virus can have complications or pass the disease on to their babies, as can breastfeeding moms. Since the COVID-19 vaccine doesn’t contain a live virus, you can’t pass anything on to the baby by being vaccinated.
What about long-term side effects of the COVID-19 vaccine?
According to clinical trial data, most side effects of COVID-19 vaccines occur within days of receiving the vaccine. Delayed effects occurring months later are rarely seen after any vaccination; most effects are seen within the four to six weeks after vaccination.
If I experience any side effects from the vaccine, how do I report them?
You can report side effects using a mobile app called v-safeSM. This app uses text messaging to initiate web-based monitoring. Any clinically important event reported by a participant is sent to the Vaccine Adverse Event Reporting System (VAERS) for follow-up.