Vaccines are available at different ages and life stages, beginning with Hepatitis B at birth and progressing through childhood, adulthood, and beyond. The timing depends on which vaccine, your age, pregnancy status, and any health conditions you have.
Hepatitis B vaccination begins at birth while core childhood vaccines start at 6 weeks of age. Your child's vaccine schedule is built around age milestones to build immunity when protection matters most. Understanding when to expect each vaccine helps you track your child's health and catch up if appointments slip.
Table of Contents
- Your Newborn's First Vaccine
- Core Childhood Vaccines: Starting at 6 Weeks
- The 4-Week Rule: How Doses Are Spaced
- Special Timing: When Your Child Turns One
- Vaccines During Pregnancy: What Is Safe
- Vaccines You Cannot Get While Pregnant
- Universal Vaccines for All Adults
- Vaccines for People 50 and Older
- What Changed About Vaccines in 2026
- Catching Up on Missed Vaccines
- Frequently Asked Questions
Your Newborn's First Vaccine
Hepatitis B vaccine is given within 24 hours of birth as standard hospital care. This is your newborn's first protection, delivered before discharge. A second dose follows at 2 months and a third at 6 months. Hepatitis B can cause serious liver disease, so starting immediately offers critical early protection.
You do not need to schedule anything special for this first dose. It happens as part of routine newborn screening and care after delivery. Confirm with your hospital ahead of time that your newborn will receive this vaccine before you go home. You will receive paperwork documenting the dose. At your first pediatric visit around 2 months, your baby receives the second Hepatitis B dose bundled with other core vaccines.
By 6 months, the Hepatitis B series is complete with the third dose. This three-dose schedule provides lasting protection. If your baby was born prematurely, the 2-month and 6-month marks are calculated from actual birth date, not due date. Ask your provider if you have questions about timing for your individual baby. Your hospital and pediatric office will coordinate Hepatitis B vaccination with other infant vaccines.
Core Childhood Vaccines: Starting at 6 Weeks
Rotavirus, DTaP (diphtheria, tetanus, pertussis), pneumococcal, and Haemophilus influenzae type b vaccines all begin at 6 weeks of age. These protect against serious bacterial and viral infections that threaten young children. The initial series continues through 18 months with multiple doses. At 6 weeks, your pediatrician administers several injections at one visit.
Your baby must be at least 6 weeks old to receive these vaccines. Rotavirus causes severe diarrhea and dehydration in infants. DTaP protects against diseases that were major childhood killers before vaccines existed. Pneumococcal vaccine prevents bacterial infections including meningitis and ear infections. Haemophilus influenzae type b causes serious respiratory and bloodstream infections in unvaccinated children.
Multiple injections at 6 weeks is normal and necessary. Your provider spaces shots in different locations (both thighs, or thighs and arms) to minimize discomfort. This approach builds protection against multiple dangerous diseases simultaneously. From 6 weeks through 18 months, these vaccines follow a specific schedule. Rotavirus is given 3 times. DTaP is given 5 times total, with the primary series done by 18 months.
Pneumococcal and Hib vaccines also continue through 18 months. Your pediatrician coordinates all timing for you. At each visit from 6 weeks onward, your provider reviews which doses your child needs next. You do not need to memorize the schedule—your clinic handles tracking and scheduling. Just keep appointments and bring your vaccination record to each visit.
The 4-Week Rule: How Doses Are Spaced
Vaccine doses must be spaced at least 28 days (4 weeks) apart for series completion. This spacing allows your baby's immune system to respond and build immunity. Doses administered 4 days or less before the minimum interval are considered valid, which means small scheduling shifts do not reset the series.
The immune system needs time between doses to develop antibodies and immune memory. Giving another dose too soon does not increase protection and may confuse the immune response. Waiting 4 weeks allows proper immune development after each dose. If a dose is given fewer than 28 days after the previous one, it is invalid and must be repeated.
For example, if your baby received a vaccine at exactly 6 weeks and you gave the next dose at 7 weeks (21 days later), that second dose would not count. You would need to wait 4 weeks from the first dose and repeat it. However, there is no upper limit on how long to wait between doses.
If your child is 3 years old and missed a dose at 18 months, you can still give that dose now and continue the series. The spacing rule applies—4 weeks between whatever doses remain—but the series does not restart. If your child is significantly behind on vaccines, your provider will map out a catch-up plan.
Doses will be spaced 4 weeks apart until the series is complete. Catching up takes time, but it works just as well as staying on the original schedule.
Special Timing: When Your Child Turns One
Measles, mumps, and rubella (MMR) vaccine cannot be given before age 12 months, though children 6 to 11 months traveling internationally may receive an early dose. This vaccine requires a more developed immune system than younger infants possess. At 12 months, your child becomes eligible for this important combination vaccine. The reason MMR is delayed relates to maternal antibodies.
Babies are born with antibodies from their mothers, which provide temporary protection against measles, mumps, and rubella. These maternal antibodies interfere with the vaccine if given too early. By 12 months, most have faded, and your baby's own immune system is ready. At 12 months, your child may receive multiple vaccines at one visit. MMR, varicella (chickenpox), and other vaccines can be given together.
Your provider will coordinate all vaccines due around this age. Your toddler may receive 2 to 4 shots at the 12-month appointment. Between 12 and 18 months, your child continues receiving doses to complete the primary vaccine series. By 18 months, many core childhood vaccines are finished. Some vaccines continue into the preschool years with booster doses.
Between 4 and 6 years old, your child receives booster doses of earlier vaccines. These boosters reinforce immunity from the primary series. School entry typically requires proof of certain vaccinations, which is why boosters align with school-age timing.
Vaccines During Pregnancy: What Is Safe
Yes, certain vaccines are safe during pregnancy and protect your newborn through transferred antibodies. The CDC recommends four vaccines for pregnant women: Tdap (at 27–36 weeks of each pregnancy), annual flu shot, COVID-19 vaccine (mRNA types only), and RSV vaccine (at 32–36 weeks). These vaccines protect both you and your baby.
Tdap (tetanus, diphtheria, pertussis) is recommended between weeks 27 and 36 of pregnancy. Getting Tdap during this window passes whooping cough antibodies to your baby. Newborns cannot receive their whooping cough vaccine until 2 months old, making these transferred antibodies critical protection. Many maternity providers recommend Tdap in the third trimester of every pregnancy. The flu vaccine (inactivated injection, not the live nasal spray) is safe throughout pregnancy.
Vaccination protects you from severe illness and passes flu antibodies to your baby. The CDC recommends flu vaccination every fall during pregnancy, regardless of how far along you are. Pregnant women can safely receive mRNA COVID-19 vaccines, which protect against COVID-19. Updated 2026 vaccines are available for pregnant people. These pass antibodies to your baby, providing protection during the newborn period when COVID-19 can be serious.
RSV vaccine is available for pregnant women at 32–36 weeks of gestation. This new option protects against respiratory syncytial virus, a common virus that can be severe in newborns. The timing in the third trimester allows antibody transfer before birth. Talk to your obstetrician or midwife about which vaccines fit your pregnancy stage.
Many providers make vaccination routine during prenatal care. These vaccines are an established, safe part of prenatal health.
Vaccines You Cannot Get While Pregnant
Live-virus vaccines should not be given during pregnancy: MMR (measles, mumps, and rubella), chickenpox (varicella), and other live vaccines should be administered before or after pregnancy. If you need these vaccines, get them before pregnancy if possible, or wait until after delivery. MMR contains weakened virus that is safe for non-pregnant people but should not be given during pregnancy.
If you received MMR before discovering pregnancy, this is not an emergency—the vaccine cannot cause infection in your baby. But if you know you are pregnant and need MMR, wait until after delivery. Chickenpox vaccine (varicella) is also live and should be avoided during pregnancy. If you are pregnant and have never had chickenpox or the vaccine, discuss this with your provider.
A blood test can check whether you have immunity from past chickenpox exposure. Rotavirus and other live vaccines are also contraindicated in pregnancy. If you need travel vaccines, coordinate with your provider about which ones are safe. Some travel vaccines are inactivated (safe during pregnancy), and some are live (to avoid). After delivery, and if applicable after finishing breastfeeding, you can receive live vaccines you missed.
Your provider can give MMR and varicella vaccines a few months postpartum. These vaccines are not emergencies and can wait for a safer time.
Universal Vaccines for All Adults
The CDC now recommends hepatitis B vaccination for all adults ages 19–59, and HPV vaccination through age 26, with shared clinical decision-making offered through age 45 for those with risk factors. These two vaccines have recently been added to universal recommendations, meaning they are recommended for nearly all adults, not just those with specific risks.
Hepatitis B vaccine is a series of 2 or 3 doses. If you received hepatitis B vaccine as a child and have lost immunity, or never received it, catching up is recommended. Healthcare workers and anyone with multiple partners should especially ensure they completed the series. HPV vaccine (human papillomavirus) protects against cancers caused by HPV, including cervical cancer, anal cancer, and some throat cancers.
Vaccination is most effective before HPV exposure, but it still offers protection if given later. The vaccine prevents future infections even if you have already been exposed to some HPV types. If you are a woman who has not been vaccinated against HPV, ask your provider about catch-up vaccination through age 26. The series is typically 2 or 3 doses depending on your age.
Women between 26 and 45 with risk factors can discuss HPV vaccination with their provider. Tdap (tetanus, diphtheria, pertussis) is recommended for all adults who have not received it. If you completed childhood DTaP, you still need one Tdap dose as an adult. After that, tetanus boosters (Td) are recommended every 10 years.
Vaccines for People 50 and Older
Shingles vaccine (Shingrix) is recommended for all adults age 50 and older, given as 2 doses spaced 2–6 months apart and is over 90% effective at preventing shingles. Shingles is a painful rash caused by reactivation of the chickenpox virus. If you had chickenpox as a child, the virus stays dormant and can reactivate years later as shingles.
Shingles pain can be severe and last for weeks or months. In older adults, pain can persist for months or years after the rash clears (post-herpetic neuralgia). Shingrix vaccine is over 90% effective and highly recommended starting at age 50. If you have already had shingles, you should still get vaccinated. Shingrix prevents recurrence and is safe for people with prior shingles.
The two doses are given 2 to 6 months apart. RSV (respiratory syncytial virus) vaccine is recommended for all adults age 75 and older, and for adults ages 60–74 with chronic lung disease, heart disease, diabetes, or weakened immunity. RSV is a common virus that can cause serious illness in older adults, including pneumonia and hospitalization.
RSV vaccine is newer, approved in 2023 and now standard for older adults. A single dose provides protection. If you are 60 to 74 with chronic health conditions, ask your provider whether you are a candidate. Updated COVID-19 vaccines are approved for all adults age 65 and older, and for younger adults 5–64 with at least one underlying condition.
Annual COVID-19 vaccination recommendations have evolved. Talk to your provider about whether you need an annual dose.
What Changed About Vaccines in 2026
In 2026, several vaccine recommendations expanded. Hepatitis B vaccine is now recommended for all adults ages 19–59, not just those with specific risks. Previously, healthcare workers and high-risk people were the main recommendation. The change means vaccinating all adults in this age range is now standard. HPV vaccine eligibility expanded: vaccination is recommended through age 26 for all, with shared clinical decision-making through age 45 for those with risk factors.
This expansion reflects the vaccine's safety record and effectiveness in preventing HPV-related cancers even when given to older adults. RSV vaccine, approved in 2023, is now offered to adults age 60 and older with risk factors, and to all adults age 75 and older. Previously there was no vaccine option for RSV.
This is a major advancement for older adults. COVID-19 vaccine recommendations were updated in 2026, with new vaccines formulated to match current circulating variants. Ask your provider whether updated COVID-19 vaccination is right for you based on age and health. If you have not been vaccinated under earlier recommendations, these 2026 updates may affect you.
An unvaccinated 35-year-old is now eligible for routine hepatitis B vaccine (not just if you have a specific risk). Ask your provider whether you should catch up on newly recommended vaccines.
Catching Up on Missed Vaccines
If your child (or you) is behind on vaccines, it is not too late to catch up. Vaccine doses must be spaced at least 28 days apart, but there is no upper limit on how long to wait between doses. If your child is 4 years old and missed a dose at 18 months, your provider can still give it now.
When catching up, your provider assesses which doses have been given and determines what remains. The 4-week spacing rule applies, so significant catch-up takes multiple visits over weeks or months. Do not worry about restarting the series—your provider counts doses already given and adds only missing ones. Missing one or two appointments does not put your child at immediate high risk if you catch up within a few months.
The longer you wait, the longer your child is unprotected. Catch-up vaccinations are often less urgent than staying on schedule, but they remain important. If your child missed vaccines and is approaching school age, catch up before enrollment. Most schools require proof of specific vaccinations. Your provider can make a catch-up plan that meets requirements before school starts.
If you are an adult who missed childhood vaccines or never received certain vaccines, ask your provider about catch-up. Many adult vaccines are single doses, while others require a series. Your provider will prioritize based on your age, health, and risk factors.
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Frequently Asked Questions
Can you get vaccines while pregnant?
Yes. The CDC recommends Tdap (at 27–36 weeks), annual flu shot, COVID-19 vaccine (mRNA types), and RSV vaccine (at 32–36 weeks) during pregnancy. These vaccines protect both you and your newborn through transferred antibodies.
What vaccines are not safe during pregnancy?
Live-virus vaccines including MMR, chickenpox (varicella), and rotavirus should not be given during pregnancy. Get these before pregnancy if needed, or wait until after delivery.
How far apart do vaccine doses need to be?
Doses must be spaced at least 28 days (4 weeks) apart. Doses given 4 days or earlier before this interval are still considered valid, but doses given 5+ days early are invalid and must be repeated.
When can your baby get the MMR vaccine?
MMR cannot be given before 12 months of age (except for children 6–11 months traveling internationally). By 12 months, maternal antibodies have faded enough that the vaccine works properly.
What happens if you miss a vaccine appointment?
It is not too late to catch up—there is no upper limit on how long to wait between doses. Your provider will determine which doses remain needed and schedule them with proper spacing.
What vaccines changed for adults in 2026?
Hepatitis B is now recommended for all adults 19–59 (not just high-risk people). HPV vaccination is available through age 26, with shared decision-making through age 45. RSV vaccine is newly available for adults 60+ with risk factors or all adults 75+.
