Frequently Asked Questions
To jump to a specific section, please click measles, COVID-19, or influenza.
Measles
1) Am I protected against measles?
2) Do I ever need a booster vaccine?
3) What should I do if I'm unsure whether I'm immune to measles?
4) How long does it take for the measles vaccine to work in your body?
5) Could I still get measles if I am fully vaccinated?
6) I've been exposed to someone who has measles. What should I do?
7) Is a baby protected if their mom was fully vaccinated?
8) Why wait until 12 months to get children vaccinated?
9) Do we have to wait for my child to be 4 years old for a second MMR dose?
COVID-19
1) What are the risks of getting a COVID vaccine?
2) Can I get COVID from a COVID vaccine?
3) What are the ingredients in COVID vaccines?
4) Since I can still get and spread COVID even if I have a vaccine, what is the point of getting vaccinated?
5) Are the COVID shots given to children the same as those given to adults?
6) If I am pregnant, or planning to become pregnant, can I get a COVID vaccine?
7) If I’ve already had COVID, do I still need a vaccine?
Influenza
1) Do I need to wait after having a flu vaccine before getting a COVID vaccine?
2) I am allergic to eggs; is it safe to receive the flu vaccine?
3) How can I get a copy of my vaccination records?
Answers to Frequently Asked Questions
Measles FAQs
1) Am I protected against measles?
CDC considers you protected from measles if you have written documentation (records) showing at least one of the following:
You received two doses of measles-containing vaccine, and you are:
A school-aged child (grades K-12)
An adult who will be in a setting that poses a high risk for measles transmission (including students at post-high school education institutions, healthcare personnel, and international travelers)
You received one dose of measles-containing vaccine, and you are:
A preschool-aged child
An adult who will not be in a high-risk setting for measles transmission
A laboratory confirmed that you had measles at some point in your life.
A laboratory confirmed that you are immune to measles.
You were born before 1957 and do not work in a high-risk occupation such as a healthcare setting.
For international travelers, CDC considers you protected from measles if you have written documentation (records) showing at least one of the following:
You received one dose of measles-containing vaccine, and you are an infant aged 6–11 months.
You received two doses of measles-containing vaccine, and you are a person 12 months or older.
A laboratory confirmed that you had measles at some point in your life.
A laboratory confirmed that you are immune to measles.
You were born before 1957.
2) Do I ever need a booster vaccine?
No. CDC considers people who received two doses of measles vaccine as children according to the U.S. vaccination schedule protected for life, and they do not ever need a booster dose.
If you're not sure whether you are fully vaccinated, talk with your healthcare provider.
3) What should I do if I'm unsure whether I'm immune to measles?
If you're unsure whether you're immune to measles, you should first try to find your vaccination records or documentation of measles immunity. If you do not have written documentation of measles immunity, you should get vaccinated with measles-mumps-rubella (MMR) vaccine. There is no harm in getting another dose of MMR vaccine if you may already be immune to measles (or mumps or rubella). Another option is to have a healthcare provider test your blood to determine whether you're immune, but this is generally not recommended.
4) How long does it take for the measles vaccine to work in your body?
For the measles vaccine to work, the body needs time to produce protective antibodies in response to the vaccine. Detectable antibodies generally appear within just a few days after vaccination. People are usually fully protected after about 2 or 3 weeks. If you’re traveling internationally, make sure to get up to date on all your measles shots. You should plan to be fully vaccinated at least 2 weeks before you depart. If your trip is less than 2 weeks away and you’re not protected against measles, you should still get a dose of measles vaccine.
5) Could I still get measles if I am fully vaccinated?
Very few people—about three out of 100—who get two doses of measles vaccine will still get measles if exposed to the virus. Experts aren’t sure why. It could be that their immune systems didn’t respond as well as they should have to the vaccine. But the good news is, fully vaccinated people who get measles seem more likely to have a milder illness. And fully vaccinated people seem also less likely to spread the disease to other people, including people who can’t get vaccinated because they are too young or have weakened immune systems.
6) I've been exposed to someone who has measles. What should I do?
Immediately call your healthcare provider and let them know that you have been exposed to someone who has measles. Your healthcare provider can:
Determine if you are immune to measles based on your vaccination record, age, or laboratory evidence.
Make special arrangements to evaluate you, if needed, without putting other patients and medical office staff at risk.
If you are not immune to measles, MMR vaccine or a medicine called immune globulin may help reduce your risk developing measles. Your healthcare provider can advise you, and monitor you for signs and symptoms of measles.
If you are not immune and do not get MMR or immune globulin, you should stay away from settings where there are susceptible people (such as schools, hospitals, or childcare) until your healthcare provider says it's okay to return. This will help ensure that you do not spread it to others.
7) Is a baby protected if their mother was fully vaccinated?
The vast majority of mothers transfer antibodies to their fetuses. Once born, antibodies wane quickly and are almost all gone at 6-12 months of age. Breastfeeding may provide some protection, but it is not a substitute for vaccination. The role of breastmilk antibodies in the protection from measles is possible, but there is a lack of robust supporting evidence. Anyone trying to conceive should have MMR titers checked, and if levels are low, MMR should be administered 28 or more days before conception.
8) Why wait until 12 months to get children vaccinated?
We try to find the sweet spot by balancing a few factors:
Maternal antibodies waning
Maturity of the immune system
The most common age of infection
That said, if there is a measles outbreak, young children need protection as soon as possible. Early vaccination is one provisional measure we can take starting at 6 months. This early dose does not count toward the two-dose series, which will still be needed at 12 months, but should protect the child in the meantime.
9) Do we have to wait for my child to be 4 years old for a second MMR dose?
The second MMR dose can be given 28 days after the first—unless it’s the MMRV vaccine, which requires a 3-month gap.
This flexibility is especially useful in outbreak areas. Healthcare providers may recommend a second dose earlier for children aged 1 to 4 who live in or are visiting outbreak areas.
Longer intervals between doses generally strengthens immunity, making some worry that shortening the measles vaccine interval could weaken protection. However, data suggest timing isn’t a major factor in long-term immunity, as long as the first dose doesn’t interfere with the second (requiring at least 4 weeks between them).
The second dose, typically given at ages 4-6, ensures protection before school, where measles spreads easily. It’s not technically a booster, but it helps cover the 7% of people who don’t respond to the first dose. Without it, gaps in immunity can fuel outbreaks.
For comprehensive FAQ lists on measles, please visit the CDC website or read this article.
COVID-19 FAQs
1) What are the risks of getting a COVID vaccine?
Worldwide, over 13.5 billion COVID vaccines have been administered to date. Some common side effects for both adults and children include pain, redness, or swelling at the injection site, tiredness, headache, muscle pain, chills, fever, and nausea. Serious side effects are rare but may occur. Accurately answering the screening questions on the consent form before getting a shot will reduce the chance of a serious side effect.
2) Can I get COVID from a COVID vaccine?
No. COVID-19 vaccines that are currently available do not use the live virus that causes COVID-19. These vaccines work by using a harmless piece of spike protein from the virus causing COVID-19 to teach the body how to fight the virus that causes it. The body then gets rid of the harmless spike protein within a few days after vaccination.
3) What are the ingredients in COVID vaccines?
Vaccine ingredients vary by manufacturer. None of the vaccines contain eggs, gelatin, latex, or preservatives. All COVID-19 vaccines are free from metals, such as iron, nickel, cobalt, lithium, and rare earth alloys. They are also free from manufactured products such as microelectronics, electrodes, carbon nanotubes, and nanowire semiconductors. There are no food proteins such as eggs or nuts, no preservatives such as thimerosal or mercury, no antibiotics, no other medications, and no animal or human tissue included in any approved COVID vaccine. None of the COVID-19 vaccines authorized or approved in the US contain any live virus.
4) Since I can still get and spread COVID even if I have a vaccine, what is the point of getting vaccinated?
You are significantly less likely to get COVID if you are vaccinated, though breakthrough infections are not infrequent. If you do get COVID after vaccination, you are significantly less likely to spread it to others and many times less likely to get seriously ill, be hospitalized, need intensive care, or die. You are also less likely to get long COVID if you have been vaccinated.
5) Are the COVID shots given to children the same as those given to adults?
The COVID-19 vaccines for children have the same active ingredients as the vaccines given to adults. However, children receive a smaller and more age-appropriate dose that is right for them. The smaller doses were rigorously tested and found to create the needed immune response for each age group.
6) If I am pregnant, or planning to become pregnant, can I get a COVID vaccine?
Yes, COVID vaccination is recommended for people who are pregnant, breastfeeding, or trying to get pregnant now, as well as people who might become pregnant in the future. People with COVID during pregnancy are more likely to deliver a preterm (earlier than 37 weeks) or stillborn infant and may also be more likely to have other pregnancy complications.
COVID vaccination during pregnancy helps prevent severe illness and death in people who are pregnant and helps protect babies younger than 6 months old from hospitalization caused by COVID.
7) If I’ve already had COVID, do I still need a vaccine?
You should get a COVID vaccine even if you already had COVID.
Getting a COVID vaccine after you recover from COVID infection provides added protection. You may consider delaying your vaccine by 3 months from symptom onset or the date of your positive test.
People who had COVID and do not get vaccinated after infection are more likely to get COVID again than those who get vaccinated after infection.
Influenza FAQs
1) Do I need to wait after having a flu vaccine before getting a COVID vaccine?
There is no recommended waiting period between getting a COVID vaccine and other vaccines. You can get a COVID vaccine and other vaccines, including a flu vaccine, at the same visit. Experience with other vaccines has shown that the way our bodies develop protection, known as an immune response, and possible side effects after getting vaccinated are generally the same when given alone or with other vaccines.
2) I am allergic to eggs; is it safe to receive the flu vaccine?
Flu vaccine is safe for most people with an egg allergy; however, please check with your doctor.
3) How can I get a copy of my vaccination records?
Visit MyVaxRecords to get a copy of your vaccination record.