At the 12-month well-child visit, your baby is due for several vaccines, including some brand-new ones and booster doses of shots they started earlier. The CDC schedule for 12 through 15 months includes up to seven or eight vaccines, though your pediatrician may spread them across a couple of visits. Here’s what to expect and why each one matters.
New Vaccines Starting at 12 Months
Three vaccines are given for the first time at this age: MMR, varicella, and hepatitis A. These are the ones most parents associate with the 12-month visit because they’re new additions to their child’s vaccine card.
MMR (measles, mumps, rubella): This is a live vaccine that protects against three diseases at once. A single dose is 93% effective against measles, 97% effective against rubella, and 72% effective against mumps. A second dose, given at age 4 through 6, raises protection even higher.
Varicella (chickenpox): Also a live vaccine, this is the first of two doses. It’s given at the same visit as MMR or sometimes as a combination shot called MMRV that covers all four diseases in one injection.
Hepatitis A: This starts a two-dose series. The second dose comes at least six months later, so your child will get it sometime between 18 and 23 months. The CDC recommends all children receive this series between ages 12 and 23 months.
Booster Doses Due at This Visit
Your child also needs booster doses of vaccines they’ve been getting since infancy. These boosters strengthen the immune response built by earlier shots.
DTaP (diphtheria, tetanus, whooping cough): The fourth dose in a five-dose series. Your child received the first three at 2, 4, and 6 months.
Hib (Haemophilus influenzae type b): This booster protects against a bacteria that can cause meningitis and pneumonia in young children. Depending on which brand was used in the earlier series, this will be either the third or fourth dose. It needs to be given at least eight weeks after the most recent Hib shot.
Pneumococcal conjugate vaccine (PCV): The fourth and final dose in the series, following doses at 2, 4, and 6 months. Your pediatrician will use either PCV15 or PCV20, both of which are currently recommended.
Why Live Vaccines Wait Until 12 Months
There’s a specific biological reason MMR and varicella aren’t given earlier. During pregnancy, antibodies from the mother cross the placenta and circulate in the baby’s blood for months after birth. These maternal antibodies are protective in the short term, but they can interfere with live vaccines, which need to replicate inside the body to trigger a proper immune response. If given too early, the mother’s lingering antibodies may neutralize the vaccine before it can do its job. By 12 months, those antibodies have faded enough that the vaccine can work as intended.
How Many Shots at One Visit
If everything is given at a single appointment, your child could receive four to six injections, which sounds like a lot. Many pediatricians split the 12-month vaccines across two visits, one at 12 months and another at 15 months, to reduce the number of shots at once. Both approaches are safe and keep your child on schedule.
One way to reduce the needle count is the MMRV combination vaccine, which combines measles, mumps, rubella, and varicella into a single shot instead of two. There’s a tradeoff, though. Children who get the combination MMRV shot have roughly twice the risk of a febrile seizure (a brief seizure triggered by fever) compared to those who get MMR and varicella as separate injections at the same visit. The absolute risk is still small: about one extra febrile seizure for every 2,300 children who receive MMRV. This increased risk applies only to the first dose at 12 through 15 months, not to the second dose given at age 4 through 6. Your pediatrician can help you decide which option you prefer.
Common Side Effects to Expect
Mild reactions are normal after the 12-month vaccines. Soreness at the injection site is the most common, affecting roughly one in four to one in five children depending on the specific vaccines given. Low-grade fever and fussiness in the first day or two are also typical.
The MMR and varicella vaccines can cause a delayed reaction that catches some parents off guard. About 5 to 12 days after the shot, some children develop a mild rash or a fever of 102°F or higher. This is actually the immune system responding to the live virus in the vaccine and is not a sign of illness. It resolves on its own within a few days.
Flu and COVID-19 Vaccines
Two additional vaccines may come up at the 12-month visit depending on timing. The annual flu shot is recommended for all children 6 months and older. If your child’s 12-month appointment falls during flu season (typically October through March), your pediatrician will likely offer it. Children under 9 getting the flu vaccine for the first time need two doses spaced at least four weeks apart.
COVID-19 vaccination is also available starting at 6 months. Your pediatrician may discuss timing based on the current formulation and your child’s situation.
If Your Child Is Behind on Earlier Vaccines
If your baby missed doses of earlier vaccines, the 12-month visit is a good time to catch up. Your pediatrician can give catch-up doses of polio, hepatitis B, or other vaccines alongside the scheduled 12-month shots. One exception is rotavirus: that vaccine has a strict age cutoff of 8 months for the final dose, so if it was missed, it can’t be given at 12 months.
Extra Vaccines for International Travel
If you’re planning international travel with your 12-month-old, a few additional vaccines may be recommended depending on your destination. Children traveling to sub-Saharan Africa’s “meningitis belt” during the dry season (December through June) should receive the meningococcal vaccine. Those heading to parts of Asia where Japanese encephalitis is common may need a two-dose series given 28 days apart, with the last dose at least one week before departure. A tick-borne encephalitis vaccine is approved for children 1 year and older who will have significant outdoor exposure in endemic areas of Europe or Asia. Talk with your pediatrician well before your trip, since some travel vaccines require multiple doses over weeks or months.