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This FAQ from the American College of Allergy, Asthma and Immunology is provided to help answer patient questions about COVID-19 vaccines. These recommendations are based on best knowledge to date, but could change at any time, pending new information and further guidance from the FDA or CDC.
Updated March 29, 2021
WHY SHOULD I RECEIVE A VACCINE AGAINST COVID-19?
Protection. A COVID-19 vaccination will help keep you from getting COVID-19 or keep you from becoming seriously ill if you get COVID-19. Having everyone get a COVID-19 vaccination is the pathway towards stopping the pandemic. FOR MOST PEOPLE, THE BENEFITS OF THE VACCINE FAR OUTWEIGH THE RISKS.
AM I A CANDIDATE TO GET A VACCINE AGAINST COVID-19?
Anyone who does not have a contraindication for taking the COVID-19 vaccine should receive it. Currently, the only contraindication is a history of a severe allergic reaction to any of the vaccine components, including sensitivity to PEG (polyethylene glycol) and/or polysorbate, which cross reacts with PEG.
While COVID-19 vaccines are not currently approved for children under age 16, safety and efficacy studies in children and adolescents are underway.
HOW DO I KNOW THE COVID-19 VACCINE IS SAFE?
Experience. Over 110,000 people participated in US clinical trials prior to approval of the current COVID-19 vaccines, and according to a March 28 statement by the CDC, more than 93.6 million people have received at least one dose of a Covid-19 vaccine, including about 51.6 million people who have been fully vaccinated by Johnson & Johnson’s single-dose vaccine or the two-dose series made by Pfizer-BioNTech and Moderna. More than 120 million people worldwide have safely received them since approval.
Safety has been demonstrated across a broad range of the population, including different ages, races, and ethnicities, as well as those with different medical conditions.
WHERE CAN I GET THE VACCINE?
Get your vaccine when you qualify and wherever it is available to you. Check with your local county and state health department for more information. New mass vaccination sites are opening up throughout the country every day.
CURRENTLY THERE ARE THREE VACCINES AVAILABLE; WHICH ONE SHOULD I TAKE?
Take whichever vaccine is available to you. The Pfizer and Moderna vaccines are very similar and are equally safe and effective. They have both met the rigorous safety standards set by the FDA. The only meaningful, minor difference is that the second dose of the Pfizer vaccine is administered 18-23 days after the first vaccination, while the second dose of the Moderna vaccine is administered 28 days after the first vaccination. You should make every effort to get the same vaccine product for both doses.
A third vaccine for COVID-19 was granted Emergency Use Authorization in late February. This vaccine is made by Johnson & Johnson (J&J) and uses an adenoviral vector that cannot replicate and contains DNA for the spike protein. Then, as with the mRNA vaccines, the muscle cells produce the spike protein which stimulates the immune system to make protective antibodies. This vaccine only requires a single dose. Note: As of April 13, 2021, the CDC and FDA have asked states to pause on administration of the J&J vaccine while more information is obtained about rare cases of blood clots. See the CDC's health alert here.
This STAT article provides a good side-by-side comparison of the Pfizer, Moderna, and Johnson & Johnson vaccines
WHY DO I HAVE TO TAKE TWO VACCINATIONS SEPARATED BY THREE TO FOUR WEEKS?
The first dose stimulates the immune system to make protective antibodies, and the second dose boosts the production of those antibodies, thereby significantly increasing your protection.
WHAT IF I DON'T GET MY SECOND VACCINATION WITHIN THE WINDOW OF TIME THAT IS RECOMMENDED?
Get your second dose as soon as you can after the minimum recommended time has passed to make sure you are as protected as you can be. Protection offered by a single dose of vaccine has been estimated to be at 50%, and the second dose increases this to more than 90%. According to the CDC, “The second dose should be administered as close to the recommended interval as possible. However, if it is not possible to adhere to the recommended interval, the second dose of Pfizer-BioNTech and Moderna COVID-19 vaccines may be scheduled for administration up to 6 weeks (42 days) after the first dose.”
DO BOTH DOSES NEED TO BE WITH THE SAME VACCINE?
Yes, if possible. The CDC says every effort should be made to determine which vaccine product was received as the first dose, in order to ensure completion of the vaccine series with the same product. The CDC also says that in exceptional situations in which the first-dose vaccine product cannot be determined or is no longer available, any available mRNA COVID-19 vaccine may be administered at a minimum interval of 28 days between doses to complete the mRNA COVID-19 vaccination series. If two doses of different mRNA COVID-19 vaccine products are administered in these situations (or inadvertently), no additional doses of either product are recommended to be given. The J&J vaccine is a single dose.
CAN I GET COVID-19 FROM THE VACCINE ITSELF?
It is not possible to get COVID-19 from any of the available vaccines or vaccines under investigation. The mRNA vaccines encode only the information for the spike protein of the virus. Similarly, the Johnson & Johnson uses an adenovirus vector which codes for the same spike protein as the mRNA vaccines. None of these can cause COVID-19. Vaccines undergo rigorous testing through clinical trials to ensure they are safe and effective for those who receive them and the COVID vaccines are being held to the same rigorous safety and effectiveness standards as all other types of vaccines in the United States.
WHAT ARE THE SIDE EFFECTS FROM THE VACCINES?
Most people do not have serious problems after being vaccinated. Your arm may be sore, red, or warm to the touch at the injection site, as can happen with injections of any kind. As sometimes happens with a vaccine, you may experience a low-grade fever, headache, and fatigue during the first 24 hours. A rash at the injection site can appear several days after vaccination, but usually goes away after a few days. These symptoms usually go away on their own and are a sign that your immune system is doing exactly what it is supposed to do: working and building up protection against disease.
WHAT ARE THE LONG-TERM SIDE EFFECTS OF THE COVID-19 VACCINES?
No long-term side effects have been identified for the currently available vaccines. The FDA and the CDC are continuing to monitor safety in the larger population, as they do with all new medical products. Part of the monitoring process includes the new “V-safe” phone app, which sends you routine texts after you receive your COVID-19 vaccine to ask brief questions about how you are feeling and what, if any, side effects you are experiencing in real time. This is an ideal way to study and document any short-term or long-term side effects from a vaccine. Be sure to download the V-safe app after you receive a COVID vaccine.
WHAT ABOUT ALLERGIC REACTIONS TO THE VACCINE?
There have been reports of a few patients experiencing anaphylaxis (a severe allergic reaction) after getting a COVID-19 vaccine. These are rare, occurring less than once for every 200,000 injections. As a result, the CDC issued guidance related to the COVID-19 vaccines and severe allergic reactions. The American College of Asthma, Allergy & Immunology (ACAAI) has also published guidance on the risk of allergic reactions to mRNA COVID vaccines. Please schedule a visit with an experienced allergist/immunologist beforehand if you have a history of anaphylaxis, mast cell disease, or concerns about receiving the vaccine.
ARE THERE ANY CONTRAINDICATIONS TO GETTING A COVID-19 VACCINE?
According to the CDC, people who have had an immediate allergic reaction, even if it was not severe, to a vaccine or injectable therapy (i.e., intramuscular, intravenous, or subcutaneous vaccines or therapies [excluding subcutaneous immunotherapy for allergies, i.e., “allergy shots”] not related to a component of mRNA COVID-19 vaccines or polysorbate), should consult their physicians to determine if they should get a COVID-19 vaccine. The CDC says this is a precaution and not a contraindication. The COVID-19 vaccines should not be given in combination with other vaccines right now, and the CDC recommends 14 days between receiving the COVID-19 vaccine and other vaccines.
Following reports of a small number of patients experiencing anaphylaxis after getting an mRNA COVID-19 vaccine, the CDC issued guidance related to the mRNA COVID-19 vaccines and severe allergic reactions. ACAAI also published guidance on the risk of allergic reactions to mRNA COVID-19 vaccines.
Patients who have an immediate (less than 4 hours) or severe allergic reaction to the first dose of the mRNA COVID-19 vaccine should not receive the second dose.
The mRNA COVID-19 vaccines should not be administered to anyone with a known history of a severe allergic reaction to any component of the vaccine. Although the specific vaccine component causing anaphylaxis has not been identified, polyethylene glycol (PEG) is one of the ingredients in these vaccine products and has been known to cause anaphylaxis. The Johnson & Johnson vaccine should not be administered to anyone who has had an immediate allergic reaction to any ingredient in the vaccine (such as polysorbate).
WHAT IF AN INDIVIDUAL HAS AN IMMEDIATE ALLERGIC TO THEIR FIRST mRNA SHOT? CAN THE JOHNSON & JOHNSON VACCINE BE GIVEN AS A “BOOSTER?”
The CDC recommends individuals discuss this with their doctor. After taking a detailed history, allergists will have a risk/benefit discussion with their patient and if the patient has no contraindications to the J&J vaccine may recommend their patient use J&J as a booster vaccination, however there is no current data on the effectiveness or safety of using the J&J vaccine this way.
SHOULD I BE VACCINATED IF I HAVE HAD AN ALLERGIC REACTION TO AN ALLERGY INJECTION OR A STINGING INSECT OR IF I HAVE A FOOD ALLERGY?
Yes. Allergic reactions to foods, medicines, or bee stings are not a reason to avoid the vaccine. However, if you have a history of anaphylaxis for any reason, we recommend your vaccination be administered in a facility that can treat allergic reactions and that you are observed for 30 minutes after receiving the vaccine.
If you have specific questions or concerns about the vaccine and whether you are a candidate to receive it, please schedule a visit to talk with an experienced allergy/immunology provider about it.
CAN I GET A COVID VACCINE ON THE SAME DAY I GET MY ALLERGY INJECTION, XOLAIR, OTHER BIOLOGIC OR GAMMA GLOBULIN INFUSION?
Administration of the vaccine with other immunizations or biologics has not been studied. Do not take a COVID-19 vaccine on the same day as your allergy injection or biologic administration. The CDC recommends a minimum interval of 14 days before or after administering other vaccines, such as the flu shot.
CAN I CONTINUE TO TAKE MY ALLERGY AND ASTHMA MEDICINE ON THE SAME DAY AS I RECEIVE MY COVID VACCINE? DOES IT LESSEN THE EFFECTIVENESS OF THE VACCINE?
Yes, take your routine medicines on the same day as getting the vaccine. There is no contraindication for any OTC or prescription allergy or asthma medicine and getting the COVID vaccines. If you don’t take medications daily, the CDC does not recommend pre-medication prior to getting the vaccine. If you have a question, please talk with your doctor.
I’VE ALREADY HAD COVID – DO I STILL NEED TO GET THE VACCINE?
Yes. The immunity offered by the vaccine may offer better/longer protection than the virus itself.
HOW SOON AFTER RECOVERING FROM COVID CAN I GET THE VACCINE?
It is safe to receive the COVID vaccine starting after COVID symptoms have resolved. If possible, get the vaccine within 90 days of getting sick from COVID 19, as your antibody protection may begin to wane by then. Wait 90 days to receive the COVID-19 vaccine if you received convalescent serum or monoclonal antibodies during your illness.
HOW OFTEN DO I NEED TO GET A COVID VACCINE? IS IT LIKE THE FLU SHOT AND I WILL NEED TO GET IT ANNUALLY?
The answers to these questions are still unknown, and this will be closely monitored as more data becomes available.
WHAT ABOUT THE NEW VARIANT STRAINS?
While the current vaccines have not been studied with the new variant COVID strains, most experts agree that it is highly likely they will offer protection against these new strains. This will be closely monitored as more data becomes available.
From a practical perspective, the discovery of these variants does not change the basic recommendations for vaccination. Specifically, right now it is not recommended that people wait for a new or changed vaccine in the hope that it will be more effective against emerging SARS-CoV-2 variants.
DO I NEED TO WEAR A FACE MASK AND AVOID CLOSE CONTACT WITH OTHERS IF I HAVE RECEIVED TWO DOSES OF THE VACCINE?
Yes. While experts learn more about the protection that COVID-19 vaccines provide under real-life conditions, it is important for everyone to continue using all the tools available to us to help stop this pandemic, like covering your mouth and nose with a mask, washing hands often, and staying at least 6 feet away from others.
Reassuring news released by the CDC in early March suggests that if you’ve been fully vaccinated:
- You can gather indoors with fully vaccinated people without wearing a mask.
- You can gather indoors with unvaccinated people from one other household (for example, visiting with relatives who all live together) without masks, unless any of those people or anyone they live with has an increased risk for severe illness from COVID-19.
- If you’ve been around someone who has COVID-19, you do not need to stay away from others or get tested unless you have symptoms.
However, if you live in a group setting (like a correctional or detention facility or group home) and are around someone who has COVID-19, you should still stay away from others for 14 days and get tested, even if you don’t have symptoms.
WHEN CAN I STOP WEARING A MASK AND AVOIDING CLOSE CONTACT WITH OTHERS AFTER I HAVE BEEN VACCINATED?
There is not enough information currently available to say when CDC will stop recommending that people wear masks and avoid close contact with others to help prevent the spread of the virus. Until we get the pandemic under control, all precautions should be taken to reduce risk of transmission among people.
WILL THERE BE ENOUGH VACCINE FOR EVERYONE?
Yes, by summer. The government has purchased enough vaccine to immunize all Americans. The goal is for there to be enough COVID-19 vaccine by May 1 to immunize all adults 16 years and up.
HOW LONG WILL PROTECTION LAST FOLLOWING VACCINATION?
We do not yet know how long protection will last following vaccination but are measuring this in both clinical trials and among groups currently being vaccinated.
WHY CAN’T CHILDREN TAKE THE COVID 19 VACCINE?
The safety of the approved vaccines has not yet been studied in children. Clinical trials in children are currently ongoing to provide this critical information.
CAN PREGNANT WOMEN AND NURSING MOTHERS BE VACCINATED?
Yes. The current CDC recommendation is that these women may choose to be vaccinated. If they have questions about getting vaccinated, a discussion with a healthcare provider might help them make an informed decision. Limited data from animal studies identified no safety concerns during pregnancy, while at the same time pregnant women who get COVID might be at increased risk of negative outcomes such as preterm birth. Studies to specifically address vaccination of pregnant women are planned.
IS A HISTORY OF RECEIVING INJECTED DERMAL FILLERS A CONTRAINDICATION TO GETTING THE mRNA COVID-19 VACCINE?
Having had dermal filler injections is not a contraindication for mRNA vaccine administration. Persons who have received dermal fillers may develop swelling at or near the site of the filler injection following administration of an mRNA COVID 19 vaccine. The symptom is temporary and treatable and has been seen with other vaccines.
SHOULD PATIENTS STILL GET A SEASONAL INFLUENZA VACCINE ANNUALLY? WHAT IS THE RECOMMENDED INTERVAL IN RELATIONSHIP TO RECEIVING THE COVID-19 VACCINE?
es, it is important to get the influenza vaccine, particularly since influenza can cause symptoms similar to COVID-19. Reducing the number of people who get severe influenza and require hospitalization will also help ensure that the health care system, hospitals, and intensive care units will not be overwhelmed should there be an increase in COVID-19 cases during flu season. The Centers for Disease Control and Prevention (CDC) recommends that COVID-19 vaccines should be administered alone with a minimum interval of 14 days before or after administration of any other vaccines due to lack of data on safety and efficacy of COVID-19 vaccines given simultaneously with other vaccines.