Frequently asked questions
Your good health is our priority. The availability of COVID-19 vaccines is a positive turning point in a public health crisis that has impacted all of us. MedStar Health is pleased to vaccinate residents of any state and the District of Columbia, ages 5 and older. The FAQ below is intended to help provide you with the most up-to-date information on COVID-19 vaccines.
How do I receive the vaccine through MedStar Health?MedStar Health is pleased to vaccinate residents of any state and the District of Columbia, ages 5 and older.
Most MedStar Health primary care practices are offering the COVID-19 vaccine same day, on demand. If you are a current MedStar Health primary care patient, please contact your primary care provider’s office or send a message via the myMedStar patient portal.
If you are not a current MedStar Health primary care patient, please click here to view which primary care practices are offering COVID-19 clinics. Please call the practice to schedule an appointment.
District of Columbia
D.C. residents can also register for a vaccine appointment at the D.C. government website or call 855-363-0333.
Maryland residents can visit the Maryland government website or call 855-634-6829.
Virginia residents can also visit the Virginia Department of Health website or call the Virginia Department of Health hotline at 877-275-8343.
Residents from any region can also find a convenient location by using Vaccine Finder at vaccines.gov.
Will I be able to choose which vaccine I want?Some of our sites know in advance which vaccine they will have. You may call the practice in advance to inquire. All the approved COVID-19 vaccines have proved to be extremely effective in reducing severe COVID-19 infections, hospitalizations, and deaths and you should feel very comfortable receiving any of the vaccines.
Can I get updates on vaccine availability by calling my primary care provider's office?Many of our MedStar Medical Group primary care practices are now offering the COVID-19 vaccine. Please call your primary care practice or send a message through the myMedStar patient portal. If you have questions about the vaccine and your specific situation that are not addressed here in these FAQs, please login to the MedStar Health patient portal to submit your question to your provider. Or, click on the feedback button at the bottom of our webpages and submit your question.
Does the research show that the COVID-19 vaccines are safe and effective?Yes. Large scale studies with a broad range of race, gender, and ethnicities have demonstrated that currently available COVID-19 vaccines are safe and effective. Each vaccine was studied in its own research trial with 30,000 to 40,000 volunteers and met the FDA’s rigorous scientific standards for safety, effectiveness, and manufacturing quality needed to support emergency use authorization (EUA). Study participants were tracked for two months following vaccination to monitor for long-term side effects, and none were noted. The U.S. Food and Drug Administration (FDA) has now fully approved the Pfizer COVID-19 vaccine for those ages 16 years and older; the vaccine continues under EUA for ages 12 to 15 years old and for booster doses for immunocompromised patients.
Since the vaccine research trials were completed, more than 230,000 million doses of the available vaccines have been administered under the most intense safety monitoring in U.S. history. Results from this monitoring are reassuring. Some people have no side effects. Others have reported common side effects after the COVID-19 vaccination, such as:
- swelling, redness and pain at injection site,
- muscle pain,
- and nausea.
These reactions are common. A small number of people have had a severe allergic reaction (called “anaphylaxis”) after vaccination, but this is extremely rare. If this occurs, vaccination providers have medicines available to effectively and immediately treat the reaction.
You can read more at the Centers for Disease Control and Prevention (CDC) COVID-19 vaccine safety site here.
Why should my child be vaccinated against COVID-19?Although fewer children have been sick with COVID-19 compared to adults, children can be infected with the virus that causes COVID-19, can get sick from COVID-19, and can spread the virus that causes COVID-19 to others. COVID-19 cases in children can result in hospitalizations, deaths, MIS-C (inflammatory syndromes) and long-term complications, such as “long COVID,” in which symptoms can linger for months. According to the Centers for Disease Control, COVID-19 hospitalizations among children and adolescents increased fivefold during a 6-week period in late June to mid-August 2021.
Similar to what was seen in adult vaccine trials, vaccination was nearly 91 percent effective in preventing complications from COVID-19 among children aged 5-11 years. In clinical trials, vaccine side effects were mild, short-lived, and similar to those seen in adults and with other vaccines recommended for children. The most common side effect was a sore arm, which can be treated with over-the-counter anti-inflammatory medication.
Are COVID-19 vaccines available for children under the age of 5?
Yes. The Advisory Committee on Immunization Practices (ACIP) and FDA recently authorized the use of COVID-19 vaccines in children under the age of 5. Two vaccines are currently authorized in this age group:
- Pfizer-BioNTech: three dose primary series, with the first two doses administered 3-8 weeks apart (3 weeks if moderately to severely immunocompromised) and the third dose administered at least 8 weeks after the second dose. More information on this vaccine can be found on the CDC’s website here.
- Moderna: two dose primary series, administered 3-8 weeks apart. Children who are moderately to severely immunocompromised should get a third dose in their primary series, with each of the three doses administered 4 weeks apart. More information on this vaccine can be found on the CDC’s website here.
Children in this age group are considered fully vaccinated and up to date two weeks after the final dose in their primary series, since there is currently no booster authorized or recommended under the age of 5.
Can the COVID-19 vaccine be safely administered with other vaccines scheduled during routine well-child checks?
Although the COVID-19 vaccine was not administered with other vaccines during study trials, observations from older children and adults shows that the COVID-19 vaccine can be safely and effectively co-administered with other vaccines. Per the CDC, children do not need to wait to be vaccinated against COVID-19 if another vaccine is administered or reschedule routine vaccines if a COVID-19 vaccine is administered. Talk with your child’s pediatrician for more information.
Is it safe for children to receive the COVID-19 vaccine?
COVID-19 vaccines have undergone – and will continue to undergo – the most intensive safety monitoring in U.S. history. Like adults, children may have some side effects after COVID-19 vaccination. These side effects may affect their ability to do daily activities, but they should go away in a few days and are treatable with over-the-counter medication, fluids, and rest. There have been reports of a condition called myocarditis (heart muscle inflammation) following vaccination with mRNA vaccines (Pfizer and Moderna); however, these are rare and the risk is much higher (nearly 40 times higher) for children sick with COVID-19 who are unvaccinated. Overwhelmingly, the COVID-19 vaccines have been shown to be safe and effective for children and adolescents.
Are doses of the COVID-19 vaccines adjusted for age?
Yes. Both Pfizer-BioNTech and Moderna COVID-19 vaccine doses are adjusted for age, with the age ranges and dose adjustments varying slightly. While most medications are weight-based to adjust for the amount of absorption by the bloodstream, vaccine doses are age-based to adjust for the maturity of the person’s immune system.
For Pfizer-BioNTech mRNA vaccines, the following age-based dose adjustments are in place:
6 months to 4 years of age – 3 micrograms (1/10th the dose of an older child or adult) given as a 3-dose primary series
5 to 11 years of age – 10 micrograms (1/3rd the dose of an older child or adult) given as a 2-dose primary series with 1 booster of the same strength currently authorized
12 to 17 years of age – 30 micrograms given as a 2-dose primary series with 1 booster of the same strength currently authorized
18 years of age and older – 30 micrograms given as a 2-dose primary series with 1-2 booster doses of the same strength currently authorized
For Moderna vaccines mRNA vaccines, the following age-based dose adjustments are in place:
6 months to 5 years of age – 25 micrograms (1/4th the dose of an older child or adult) given as a 2-dose primary series
6 to 11 years of age – 50 micrograms (1/2 the dose of an older child or adult) given as a 2-dose primary series
12 to 17 years of age – 100 micrograms given as a 2-dose primary series
18 years of age and older – 100 micrograms given as a 2-dose primary series with 1-2 half-strength booster doses currently authorized
Talk with your doctor about which dose is right for you or your child, as there may be additional adjustments based on whether your immune system is weakened (moderately to severely immunocompromised).
There is only one available dose of the viral vector Janssen J&J vaccine, which is not available for individuals younger than age 18 and is only recommended in certain clinical scenarios. Talk with your doctor if you are considering or have previously received Janssen’s J&J vaccine.
I've heard about possible adverse reactions to the Johnson & Johnson (J&J) vaccine? Is it safe?Yes. After a careful and detailed medical review, the Advisory Committee on Immunization Practices (ACIP) and CDC recommend vaccination with the J&J/Janssen COVID-19 Vaccine resume among people 18 years and older due to the benefit outweighing this exceedingly rare complication.
Will the COVID-19 vaccine prevent me from getting serious COVID-19 disease?
Experts have stressed that all three vaccines (Moderna, Pfizer, and Johnson & Johnson) are highly effective against serious COVID-19 disease. All studies showed zero deaths and very few to no hospitalizations among fully vaccinated individuals.
Remember, even with a COVID-19 vaccine, you should continue to wear a face mask, wash your hands often, and practice physical distancing, since you can temporarily carry the virus and transmit it to other people.
Can I get COVID-19 from the vaccine, or expose my family to the COVID-19 virus because of the vaccine?No. None of the authorized and recommendedCOVID-19 vaccines or COVID-19 vaccines currently in development in the United States contain the live virus that causes COVID-19. This means that a COVID-19 vaccine cannot make you sick with COVID-19.
COVID-19 vaccines teach our immune systems how to recognize and fight the virus that causes COVID-19. Sometimes this process can cause symptoms, such as fever. These symptoms are normal and are signs that the body is building protection against the virus that causes COVID-19. Learn more about how COVID vaccines work.
It typically takes a few weeks for the body to build immunity (protection against the virus that causes COVID-19) after vaccination. That means it’s possible a person could be infected with the virus that causes COVID-19 just before or just after vaccination and still get sick. This is because the vaccine has not had enough time to provide protection.
If you develop symptoms of COVID-19 after vaccination, or think you are having severe side effects to the vaccine, call your healthcare provider right away.
Were the vaccines studied in people from different ages, ethnicities, and gender groups?
Pfizer reports that about 10% of the more than 40,000 volunteers in its safety and effectiveness trials for this vaccine identified as Black or African American, and one in four identified as Hispanic or Latino. These participants included men, women, and children between the ages of 12 and 75. Also, the vaccine was shown to be more than 94% effective in adults over 65 years of age.
The Moderna vaccine was studied in more than 30,000 volunteers over the age of 18; 25% were 65 years of age or older, 1 in 5 were Hispanic or Latino, one in 10 were African American. Demographic characteristics were similar among participants who received Moderna COVID-19 Vaccine and those who received placebo.The Johnson & Johnson vaccine was a global study that included nearly 44,000 participants living in the United States, Brazil, South Africa, and other Latin American countries. Because of its global outreach, a higher percentage of Latino or Hispanic participants were enrolled in this study (44% globally; 14% in the U.S.). Additionally, 17% identified as Black or African American, 4% as Asian, and 8% as Native American (1% in the U.S.). Median age of study participants was 51, with an age range of 18-100, and 40% of participants had at least one medical problem (comorbidity), including obesity, high blood pressure, and diabetes.
The Johnson & Johnson vaccine was a global study that included nearly 44,000 participants living in the United States, Brazil, South Africa, and other Latin American countries. Because of its global outreach, a higher percentage of Latino or Hispanic participants were enrolled in this study (44% globally; 14% in the U.S.). Additionally, 17% identified as Black or African American, 4% as Asian, and 8% as Native American (1% in the U.S.). Median age of study participants was 51, with an age range of 18-100, and 40% of participants had at least one medical problem (comorbidity), including obesity, high blood pressure, and diabetes.
What do vaccine efficacy numbers really mean?The efficacy of a vaccine is determined by its ability to prevent cases of a disease, such as COVID-19. For the Pfizer, Moderna, and Johnson & Johnson vaccines, efficacy was defined as the ability of the vaccine to prevent cases of COVID-19 a certain number of days after vaccination. The studies also looked at whether the vaccines prevented hospitalization and death, among other things. Vaccine efficacy is calculated by comparing the number of disease cases among people who received the vaccine to the number of disease cases among those who didn’t (the placebo group).
The efficacy of a vaccine is determined by its ability to prevent cases of a disease, such as COVID-19. For the Pfizer, Moderna, and Johnson & Johnson vaccines, efficacy was defined as the ability of the vaccine to prevent cases of COVID-19 a certain number of days after vaccination. The studies also looked at whether the vaccines prevented hospitalization and death, among other things. Vaccine efficacy is calculated by comparing the number of disease cases among people who received the vaccine to the number of disease cases among those who didn’t (the placebo group).95% efficacy against COVID-19 means that the vaccinated individual has a 95% lower risk of getting COVID-19 than those who weren’t vaccinated. It does NOT mean that 5% of those who are vaccinated will get COVID-19—far from it. For comparison, the efficacy of the childhood vaccination we all get against measles, mumps, and rubella (MMR) vaccine is 97% against measles and 88% effective against mumps. The efficacy of the seasonal flu vaccine is between 40% and 60%. In contrast, the efficacy against severe COVID-19 disease is 95% in Moderna and Pfizer, and 85% in Johnson & Johnson, all very high, and all considered to be extremely effective by experts.
95% efficacy against COVID-19 means that the vaccinated individual has a 95% lower risk of getting COVID-19 than those who weren’t vaccinated. It does NOT mean that 5% of those who are vaccinated will get COVID-19—far from it. For comparison, the efficacy of the childhood vaccination we all get against measles, mumps, and rubella (MMR) vaccine is 97% against measles and 88% effective against mumps. The efficacy of the seasonal flu vaccine is between 40% and 60%. In contrast, the efficacy against severe COVID-19 disease is 95% in Moderna and Pfizer, and 85% in Johnson & Johnson, all very high, and all considered to be extremely effective by experts.
It’s important to know that vaccine efficacy has NOT been determined for cases where someone has the infection but is not aware because they don’t have symptoms. This means that vaccinated individuals may still become infected with the virus and possibly spread it to others, even if they don’t get sick themselves. Until enough people in our community are vaccinated (to achieve herd immunity), we must continue to practice physical distancing and mask use to prevent the spread of the virus.
Who decides if the new vaccines are safe and approved?The U.S. Food and Drug Administration (FDA) must determine that a vaccine is safe and effective before it approves it. As part of the process, the vaccine company must conduct clinical trials. During these trials, participants are watched carefully for any side effects, and scientists, physicians, and nurses collect information about everything that happens. Before the vaccine is approved, this information is reviewed by an independent group of scientists who do not work for the company making the vaccine or the government. The independent group shares results of its review with the company, which must use this information when they apply to the FDA for approval.
See information from the FDA about approval for COVID-19 vaccines here.
Learn more about how CDC is making COVID-19 vaccine recommendations here.
How was the new vaccine developed so quickly?Scientists have been working on the technology used in the currently available vaccines for years. The unique nature of the COVID-19 pandemic prompted urgency and a critical need for private and public sectors to increase time, funding, and expertise devoted to this vaccine. These additional resources allowed the vaccine to be developed more quickly, while ensuring safety. Read more about this FDA process here.
Why are there so many different types of vaccines?To help quickly end the global pandemic, multiple pharmaceutical companies worked to develop a vaccine that would prove effective against COVID-19. There were dozens started, seven that are promising, and three to market so far. Some of these vaccines have different mechanisms, but all target the virus that causes COVID-19. It is not uncommon for multiple medications and vaccines to be developed that act differently to treat or prevent the same condition. It is possible that more vaccines will be approved to help prevent COVID-19, and those may also work differently than the ones that have already been approved. Having a range of vaccines that work in different settings helps the local, statewide, and national teams who are focused on vaccination target their approach to outreach, and will help control the pandemic faster than if there were only one available.
Are there any exclusions to receiving a COVID-19 vaccine?Do NOT take the Pfizer, Moderna, or Johnson & Johnson vaccine if you have:
- A fever above 38°C (100.4°F).
- Tested positive for COVID-19 within the last 10 days; 20 days from testing positive if you were hospitalized due to COVID-19.
- A severe allergy or anaphylaxis to any substance containing polyethylene glycol (PEG) (for the Moderna or Pfizer vaccine) including bowel prep (e.g., GoLytely), or polysorbate (Johnson & Johnson).
- A severe allergy or anaphylaxis to any substance containing polyethylene glycol (PEG) (for the Moderna or Pfizer vaccine) including bowel prep (e.g., GoLytely), or polysorbate (Johnson & Johnson).
- If you have severe allergic reactions (requiring Epi-pen),talk with your doctor before scheduling.
Can I take the vaccine if I am pregnant?Yes, if you are pregnant, you might choose to be vaccinated. Based on how COVID-19 vaccines work, experts think they are unlikely to pose a specific risk for people who are pregnant. However, there are currently limited data on the safety of COVID-19 vaccines in pregnant people because these vaccines have not been widely studied in pregnant people. Systems are in place to continue to monitor vaccine safety, and so far, they have not identified any specific safety concerns for pregnant people. Clinical trials to evaluate the safety and efficacy of COVID-19 vaccines in pregnant people are underway or planned.
If you are pregnant and have received a COVID-19 vaccine, we encourage you to enroll in v-safe, CDC’s smartphone-based tool that provides personalized health check-ins after vaccination. A v-safe pregnancy registry has been established to gather information on the health of pregnant people who have received a COVID-19 vaccine.
Because pregnant women are at higher risk for complications from COVID-19, the American College of Obstetricians and Gynecologists, the Society for Maternal Fetal Medicine, and MedStar Health obstetricians recommend that COVID-19 vaccines can be given during pregnancy. If you have questions about receiving the vaccine during pregnancy, discuss with your obstetrical provider.
Can I take the vaccine if I am immunocompromised or on immunosuppressant medications?All currently available vaccines are considered safe for immunosuppressed people or those on immunosuppressants. Talk with your doctor for help making an informed decision.
Can I take the vaccine if I am anticoagulants or have a bleeding disorder?All currently available vaccines are considered safe for people with a history of bleeding disorders or on anticoagulants. Apply extra pressure after vaccination to the injection site to reduce bleeding.
I had COVID-19. Why must I wait 10 days before I get the COVID-19 vaccine?For the safety and protection of our staff and patients, and in accordance with guidelines, you should quarantine for 10 days once you have tested positive for the virus and 20 days from testing if you were hospitalized due to COVID-19.
How many people need to be vaccinated to achieve herd immunity?According to the CDC, up to 90 percent of individuals may have to be vaccinated before enough people in the community are immune to the virus so that it doesn’t easily spread. At this time, we have not achieved herd immunity through vaccination. We hope after you have a good vaccination experience you will share this with your friends and family and encourage others to vaccinate as well for the good of the community.
When should I get the 2nd primary dose of the COVID-19 vaccine?
The following recommendations apply for individuals aged 5 and older based on which vaccine was received as the first primary dose.
- Pfizer-BioNTech: the second primary dose vaccine should be given 3-8 weeks after the first dose
- Moderna: the second primary dose vaccine should be given 4-8 weeks after the first dose
- Johnson & Johnson’s Janssen: there is only 1 dose in the primary series for this vaccine
Talk to your healthcare or vaccine provider about the timing for the second primary dose in your vaccine series. Special considerations exist for the following groups:
- People ages 5 through 64 years, and especially males ages 12 through 39 years, may consider getting the secpmd primary dose of an mRNA COVID-19 vaccine (Pfizer-BioNTech or Moderna; Pfizer-BioNTech only for children ages 5 through 17 years) eight (8) weeks after the first dose. A longer time between the first and second primary doses may increase how much protection the vaccines offer, and further minimize the rare risk of heart problems, including myocarditis and pericarditis.
- People ages 65 years and older, people more likely to get very sick from COVID-19, or anyone wanting protection due to high levels of community transmission should get the second primary dose of Pfizer-BioNTech COVID-19 vaccine 3 weeks (or 21 days) after the first primary dose, or the second primary dose of Moderna COVID-19 vaccine 4 weeks (or 28 days) after the first primary dose.
Visit the CDC's website on booster doses for more information
Should I take my prescribed medications the day of my vaccination appointment?
Yes, it is important that you continue to take all medications even on the day of your vaccine appointment. Both the vaccine and your medications will continue to be effective and they will not negatively impact each other.
What else should I do I do the day of my vaccine?
Be sure to have some fluids in your system and if your appointment is around a mealtime, it is perfectly ok to eat something beforehand. You don’t want to go to your appointment hungry or thirsty.
It’s important to know that the vaccine is delivered in your upper arm, so wear clothing that allows a clinician to easily access your upper arm. Consider wearing a short-sleeved shirt, or wear a short-sleeved shirt under a sweater or jacket that can be easily removed.
Can I get a COVID vaccine booster dose?
The Centers for Disease Control and Prevention (CDC) and Federal Drug Administration (FDA) approved the emergency use authorization (EUA) for three COVID-19 vaccines in the United States, including booster dose recommendations for each vaccine. The following guidance exists for a first booster dose following completion of the primary vaccine series:
Individuals 18 years of age and older can get any of the COVID-19 vaccines authorized in the United States. Pfizer-BioNTech or Moderna (COVID-19 mRNA vaccines) are preferred. You may get Johnson & Johnson’s Janssen COVID-19 vaccine in some situations.
Individuals 5-17 years old can ONLY get a Pfizer-BioNTech COVID-19 vaccine booster. It is currently the only vaccine authorized for administration among this age group.
The FDA has authorized “mix and matching” booster doses for those 18 years of age and older so that either mRNA vaccine (Pfizer-BioNTech or Moderna) can be administered for a booster; however, it is recommended you receive the same product as your original vaccination series (see above for recommendations regarding booster doses after receiving Johnson & Johnson’s Janssen vaccine). If you wish to receive a booster from a specific manufacturer, contact the location in advance to determine if it has the product you want.
Individuals are eligible for a first booster dose at least five months following immunization with the Pfizer-BioNTech or Moderna vaccine, or two months following immunization with a single dose of Johnson & Johnson’s Janssen vaccine. These intervals may be shorter if you have certain health conditions that compromise your immune system. Talk with your healthcare provider about optimal timing for a booster dose based on your personal health history. Full CDC guidance on primary series and booster dose scheduling can be found here.
How long should I wait to get my booster after contracting COVID-19?
If you have recently recovered from a COVID-19 infection, you do not need to wait to receive a booster but may consider delaying until three months following the onset of symptoms or, if asymptomatic during your infection, three months after your first positive test. Talk with your healthcare provider about optimal timing for a booster dose after contracting COVID-19.
The following guidance exists for specific populations:
- You do not need to wait any interval of time after receiving a monoclonal antibody infusion to get a booster dose for COVID-19.
- If you received EVUSHELD for pre-exposure prophylaxis, wait two weeks until getting a booster dose for COVID-19.
Who is eligible to receive a second booster dose?
A second booster dose has been authorized for specific populations who are at higher risk of developing complications or being hospitalized because of COVID-19 infection. The following individuals are eligible for a second booster dose with an mRNA vaccine (Pfizer or Moderna) if it has been at least four months since their previous booster:
- Any individual aged 50 and older
- Any individual 12 and older with an immunocompromising condition (Pfizer mRNA vaccine only)
- Any individual who received Johnson & Johnson’s Janssen vaccine for both their primary series and first booster, regardless of age.
There are no known increased safety risks to getting a second booster dose, even if additional booster doses are recommended in the future. Studies have shown that immunity wanes approximately four months after a first booster dose for those who are not immunocompromised. Individuals with chronic disease are at an increased risk of COVID-19 complications, so it is important that you talk with your healthcare provider to understand your risk and whether a booster is right for you.
I meet the criteria. How do I schedule a booster?MedStar Health primary care practices are offering the COVID-19 Pfizer booster and immunocompromised third dose to those who meet the above criteria same day, on demand. If you are a current MedStar Health primary care patient, please contact your primary care provider’s office or send a message via the myMedStar patient portal.
If you are not a current MedStar Health primary care patient and you meet the above Pfizer vaccine booster dose criteria or immunocompromised third dose criteria, please click here to view which primary care practices are offering COVID-19 clinics. Please call the practice to schedule an appointment. You also can visit vaccines.gov to find a location that is convenient to you.
Updated July 8, 2022 10:00 a.m.