Ending COVID-19 starts with you. It is important that you get your initial vaccine shots and your booster shot as soon as you can. The vaccines are our best defense against the virus.

COVID-19 vaccines are free and recommended for everyone age 5 and older. They are safe and effective.

Learn more about:

Getting Your Primary Vaccine Series

You are considered vaccinated two weeks after your primary vaccine series. This means two weeks after either the second dose of a two-shot vaccine (Pfizer-BioNTech or Moderna) or the single-shot Johnson & Johnson vaccine.

Pfizer and Moderna are preferred over the Johnson & Johnson vaccine by the Centers for Disease Control and Prevention (CDC).

The CDC says serious side effects from the vaccines that lead to long-term health problems are highly unlikely. The benefits of getting vaccinated outweigh the risks.

Ask your doctor any specific questions you have about the vaccines. Please visit umms.org/vaccine for more information.

Initial Vaccines for Adults

Adults (18 and older) can choose any of the three approved COVID-19 vaccines for their primary series.

You cannot get the COVID-19 vaccine if you:

  • If you get the Pfizer vaccine, you will need your second dose 3 weeks (21 days) after receiving the first dose.
  • If you choose Moderna, you will need your second dose 4 weeks (28 days) after your first dose.
  • Johnson & Johnson is a single-dose vaccine.

Vaccines are not interchangeable for your primary series (as in you cannot get Pfizer for your first shot and Moderna for your second shot).

Initial Vaccines for Children and Adolescents

Only the Pfizer vaccine is authorized for children and adolescents ages 5 to 17. Children 5 to 11 get an age-appropriate dose, and adolescents 12 and older receive the same dose as adults.

Like adults, children and adolescents need their second Pfizer dose three weeks after their first shot. If a child turns 12 in between their first and second dose, their second dose should be the dose given to adolescents and adults, per the CDC.

Additional Doses of the COVID Vaccine

Booster Shots

Everyone age 12 years and older should get a booster shot as soon as they are eligible.

  • The CDC now recommends booster shots at five months after the completion of the primary vaccination series of either the Pfizer or Moderna vaccine.
  • Teens ages 12 through 17 can only get the Pfizer booster shot.
  • The booster interval recommendation for those who received the Johnson & Johnson vaccine is two months.

Additional Doses for Immunocompromised People

Some moderately or severely immunocompromised people should get an additional primary shot as part of their primary vaccine series. This means three doses of Pfizer or Moderna vaccine or two doses of the Johnson & Johnson vaccine. Pfizer and Moderna are preferred over the Johnson & Johnson vaccine. Immunocompromised people also should get a booster shot. If you are eligible for an additional primary shot, get it before getting a booster shot. Immunocompromised children ages 5 to 17 should complete an additional dose of the Pfizer vaccine in their primary series (three doses total).

What to Consider Before Getting a Vaccine

There are certain factors you should discuss with your doctor prior to getting vaccinated. For instance, if you have a weak immune system or take a medication that suppresses your immune system, you should ask your doctor about whether that would impact the effectiveness of a COVID-19 vaccine.

Also consult your doctor if you:

  • Have allergies (Continue reading for more information on allergic reactions.)
  • Have a bleeding disorder or are taking a blood thinner (You may get vaccinated if your doctor determines you can receive a vaccine intramuscularly with reasonable safety, according to the CDC.)
  • Are pregnant, planning to become pregnant or are breastfeeding (COVID-19 vaccines are recommended for these women.)

If You Have Allergies

For your safety, you should speak with your doctor before receiving a COVID-19 vaccine if you have ever had an immediate allergic reaction to another vaccine or injectable therapy. This kind of reaction can occur within four hours after vaccination and cause symptoms such as:

  • Hives
  • Swelling
  • Wheezing/respiratory distress

A severe allergic reaction—also called anaphylaxis—necessitates treatment with epinephrine (EpiPen) or hospital admission. If you think you are having a serious allergic reaction to a COVID-19 vaccine, call 911 immediately.

The CDC does not recommend getting the same vaccine if you previously had a severe or an immediate allergic reaction to any of its ingredients; you should switch to another vaccine. Polyethylene glycol (PEG), contained in the mRNA vaccines, and polysorbate, which is in the Johnson & Johnson Janssen vaccine, are among the notable ingredients linked to possible allergic reactions. If you are allergic to these or any other ingredients in a COVID-19 vaccine, ask your doctor what safer vaccine options are available to you.

The CDC does recommend vaccination if you have a history of allergic reactions that are unrelated to vaccines or injectable medications.

Anyone who has a severe allergic reaction to a particular COVID-19 vaccine should not get another dose of that same vaccine.

Are You at Increased Risk for COVID?

Certain circumstances make getting a COVID-19 vaccine more urgent. Consider that in addition to having a weakened immune system:

  • Being an older adult, particularly if you are older than 65, makes you more vulnerable to severe illness from COVID-19.
  • Underlying medical conditions (such as cancer, heart and neurological conditions, diabetes, obesity and chronic kidney disease) also increase your risk of severe illness from the virus.
  • Living and working in a congregate setting or long-term care facility, as well as other high-risk occupations (e.g., frontline health care, retail, public transportation) puts you at increased risk of exposure to the virus.

When Waiting to Get Vaccinated Is Necessary

You should delay or reschedule your vaccination if:

  • You feel sick (to avoid potentially spreading the virus to others). Once you have recovered and have not had a fever in the past 24 hours, then it will be safe to proceed with vaccination.
  • It has not been 90 days since you were treated for COVID-19 with monoclonal antibodies or convalescent plasma while sick with the virus
  • It has not been 30 days since you received monoclonal antibodies or convalescent plasma after you were exposed to someone with COVID-19
  • You have been diagnosed with COVID-19 and do not meet the criteria for discontinuing isolation. Once you are released from isolation, then it will be safe to proceed with vaccination.
  • The CDC says you should consider delaying vaccination for 90 days after the date of diagnosis of multisystem inflammatory syndrome in adults or children (MIS-A or MIS-C) and until you have recovered from a related illness.

Preparing for Your Vaccine Appointment

Contact the facility where your COVID-19 vaccine will be administered or review your confirmation email so you know what to do before, and bring to, your appointment. Make sure to wear a well-fitting mask (preferably a KN95 mask) to the vaccine appointment. If you have not yet had your annual influenza vaccine, then plan to try and have this completed in the same visit.

It is not recommended that you take antihistamines or over-the-counter medicine (like aspirin, ibuprofen or acetaminophen) before getting your shot in order to prevent vaccine-related side effects, as it is not known how these medications might affect the vaccine's effectiveness. Do continue taking medications you normally take for other medical conditions.

When Getting Your Shot

At your vaccination appointment:

  • Be prepared to answer screening questions about your current state of health and medical history (allergies, previous vaccinations, underlying medical conditions, etc.). You also may need to review and sign a consent form.
  • You and your healthcare provider should wear well-fitting masks (covering the nose and mouth) during your appointment.
  • You should be monitored onsite for at least 15 minutes after receiving your shot.
  • Maintain a distance of at least six feet from others while at the healthcare facility whenever possible.
  • Be prepared to schedule an appointment for your second shot at the time of your first.

At your first vaccination appointment, you should get a vaccination card that tells you what COVID-19 vaccine you received along with when and where you received it. Keep this card for future use (you will need to have it with you when you go for your second shot) and consider taking a picture of it as a backup.

Learn how to request a vaccine card replacement in Maryland.

After Your Vaccine Shot

If it has not been two weeks since you got either the second of a two-dose vaccine or the single-shot Johnson & Johnson vaccine, you are not considered fully vaccinated. Make sure to complete your booster dose of vaccine as soon as you are eligible to ensure your vaccination is up to date.

Breakthrough COVID-19 Infections

Always keep in mind that COVID-19 vaccines are not 100% effective at preventing infection. Someone who is fully vaccinated and boosted can still get the virus. The good news is that fully vaccinated people who get infections tend to experience less severe symptoms than do unvaccinated people. They are also much less likely to be hospitalized or die from the virus.

If you suffer an infection or exposure, you might be contagious, so please take the necessary steps to protect others, including quarantining and isolating yourself. Learn more about how to treat COVID at home.

Possible Side Effects From COVID-19

Adults and children may experience some side effects from their vaccine, but usually these are normal signs that the body is building protection against COVID-19. Some people have no side effects. Allergic reactions are possible but rare, according to the CDC. Side effects after the second shot may be more intense than those experienced after the first shot, but they should go away within a few days.

Common side effects of the vaccine include pain, swelling and redness on the arm where you received your shot, as well as:

  • Tiredness
  • Headache
  • Muscle pain
  • Chills
  • Fever
  • Nausea

Call your doctor:

  • If redness or tenderness where the shot was administered gets worse after 24 hours
  • If your side effects are concerning or do not seem to improve after a few days
  • If you do not have a doctor, please call the UMMS Nurse Call Line (1-888-713-0711), which is open 24 hours a day, 7 days a week.

To reduce pain and discomfort in the area of your arm where your shot was given, try applying a clean, cool, wet washcloth to the area or exercising your arm. The CDC recommends drinking plenty of fluids and dressing lightly to reduce discomfort from fever after your shot.

Although over-the-counter medications are not recommended prior to vaccination, it is OK to take these for any discomfort that occurs after getting vaccinated. Ask your child's healthcare provider about using a non-aspirin pain reliever as well as other remedies for comforting your child at home after vaccination, the CDC says.

Rare Side Effects

There have been rare side effects associated with the COVID-19 vaccines. The chances of these side effects occurring are low. The CDC continues to recommend vaccination for individuals 12 and older, given the high risk of more severe complications from COVID-19 illness.

Please see the Food and Drug Administration EUA Fact Sheets for each vaccine for more information about rare side effects.

Reporting Adverse Events

If you have any adverse events after getting your vaccine shot, you can report them to the FDA/CDC Vaccine Adverse Event Reporting System (VAERS). You can do this online at vaers.hhs.gov or by calling the toll-free number (1-800-822-7967).

The CDC also has an optional text-message-based tool called v-safe. You can report any side effects to v-safe. You can also get automated, personalized health check-ins after your first COVID-19 shot and reminders about the second shot. For more information, visit cdc.gov/vsafe.

What Else Can I Do?

  • If you have not completed your annual flu vaccination, then obtain it as soon as possible.
  • If you think you've been exposed to a person with a COVID-19 infection, then you should seek testing while you are quarantining.

Updated 1/7/2022

UMMS provides our expert-reviewed content to keep our community informed. When sharing this copyrighted content, please link to our site so that critical updates are reflected.