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Vaccine FAQs: Side Effects and Management

1. What is the best way to manage side effects from the vaccine?
Some people are reporting side effects from the vaccine, particularly the second dose, as their bodies mount an immune response.

Symptom management is recommended, such as acetaminophen or ibuprofen for headaches or body aches, anti-nausea medication, and overall rest and hydration.  It is not recommended to take acetaminophen, ibuprofen, Benadryl, or other medications before receiving the vaccine.

2. Are there any severe or long-term side effects that may occur as a result of the vaccine?

Most significant side effects are related to the response from our immune system when producing antibodies. This can include headache, fever, muscle aches, chills, and sometimes nausea and vomiting. These reactions are more common after the second dose of the vaccine, and can usually be handled by using medications such as ibuprofen or acetaminophen. Persons who have previously been infected with COVID may experience more of these side effects. 
Anaphylactic reactions have been reported, but they are very rare.  The risk of a true anaphylactic reaction varies slightly depending on the vaccine, but is estimated to be around one-thousandth of one-percent, or 1 in 100,000. Patients with a history of anaphylactic reactions to previous vaccines or other injectable products are advised to consider scheduling an appointment with an allergist to discuss their risk of a reaction to the COVID vaccines.  Additionally, patients with a significant history of allergic reactions are requested to wait for 30 minutes after receiving the vaccine before leaving the clinic site, rather than the typical 15 minutes.

Benadryl before the vaccine is not recommended.

Information about anaphylaxis rates of each vaccine can be found here: 3. How do we know these vaccines won’t have long-term side effects?

In the history of vaccines, serious side effects became apparent within 6-8 weeks of the person receiving the vaccine.  There is no currently-known mechanism in vaccines for something to “show up years later.” mRNA vaccines have been in studies and clinical trials for nearly 20 years, including for influenza, Zika and rabies viruses.  Some cancer research has successfully used mRNA to teach the immune system to target specific cancer cells.

People often think of “long-term side effects” in relationship to medications. But vaccines and maintenance medications are two very different types of drugs.  Vaccines are given to prompt the body’s immune system to create antibodies (just like with other vaccines and infections) and then the vaccine ingredients are quickly eliminated from the body.  Medications, which are often taken for months, years or even decades, are far more known for delayed or “long term” side effects due to the continuous exposure of the drug over long periods of time; this is why people taking certain medications to manage chronic conditions are carefully monitored for side effects.

COVID-19 itself frequently leads to long-term side effects.  Studies show that at least 1 in 10 of infected adults have developed some form of “long COVID”, and that number rises to as high as 1 in 4 in patients who are hospitalized.  This can lead to everything from a reduction in quality of life, all the way to severe permanent disability.

4. What is the relationship between the vaccine and Bell’s palsy?

There have been several cases of Bell’s palsy reported in both vaccines. This number is higher than the placebo group. However, over the course of one year, the number of patients in a 20,000 patient sample (the size of the Pfizer vaccine group), who would be expected to develop Bell’s palsy would be approximately 3 to 6, assuming no effect from the vaccine. In the study, four patients who received the Pfizer vaccine developed Bell’s palsy compared to none in the placebo group; three patients who received the Moderna vaccine developed Bell’s palsy compared to one patient in the placebo group.
Bell’s palsy is generally considered to be a temporary condition that may resolve with or without treatment. It should be noted that the annual incidence of Bell’s palsy is between 15 and 30 per 100,000 people per year.
The CDC has this information posted on their website, for people who have previously had Bell’s palsy:
Cases of Bell’s palsy were reported in participants in the mRNA COVID-19 vaccine clinical trials.

However, the Food and Drug Administration (FDA) does not consider these to be above the rate expected in the general population. They have not concluded these cases were caused by vaccination. Therefore, persons who have previously had Bell’s palsy may receive an mRNA COVID-19 vaccine.

5. What about myocarditis in teenagers?

You may have heard news about a small number of teens/young adults who experienced temporary heart inflammation (called myocarditis) after receiving the mRNA COVID-19 vaccine.

These cases are being carefully studied to see if there is any link to the vaccine, as a small number of myocarditis cases occur in young people without the vaccine as well.  At this time, the CDC has added a warning label regarding the possible side effect of myocarditis in young patients receiving the Pfizer or Moderna vaccine.  The cases are usually mild and do not require hospitalization, and the analysis of the data still shows that the benefit of the vaccine outweighs the risk.  COVID-19 infection sometimes causes myocarditis and other heart issues, which are at higher rates than from the vaccine.

The American Academy of Pediatrics has more information on their website, at, and continues to recommend the COVID-19 vaccine to patients ages 12 and older.  Parents with concerns are encouraged to talk with their child’s doctor.

6. What is the risk of blood clots with the Johnson and Johnson vaccine?

Blood clots associated with the Johnson and Johnson vaccine are extremely rare (approximately 1 per million), but appear to be more common in women 18 to 49 years of age.  The American Society of Hematologists recommend that: “Risk of death and serious outcomes of COVID-19, including thrombosis, far outweigh the blood clot risk possibly associated with highly efficacious vaccines.”

Please also note that severe blood clots, including those that cause serious strokes, are a common complication of COVID-19.  The risk of blood clots from a COVID-19 infection is much greater than from a COVID-19 vaccine.

7. Is there an increased risk of Guillain-Barre Syndrome (GBS) after receiving the COVID vaccine?

There does not appear to be an increased risk of Guillain-Barre Syndrome with either of the mRNA vaccines.  There may be an increased risk of GBS with the JnJ vaccine based on reports, but the incidence of GBS is still quite rare.

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