The vaccines you need depend largely on your age, but a core set protects against serious and sometimes fatal infections at every stage of life. For children, the recommended schedule includes vaccines against 14 diseases, starting at birth. Adults need annual flu shots, periodic tetanus boosters, and several additional vaccines as they age. Here’s a practical breakdown of what’s recommended and when.
Vaccines for Infants and Young Children
The childhood immunization schedule is the most intensive period of vaccination, because young immune systems are vulnerable to infections that rarely threaten healthy adults. These vaccines are recommended for all children:
- Hepatitis B: First dose at birth, with two more doses by 18 months.
- DTaP (diphtheria, tetanus, pertussis): Five doses total, starting at 2 months and finishing between ages 4 and 6.
- Hib (Haemophilus influenzae type b): Protects against a bacterial infection that can cause meningitis. Three or four doses between 2 and 15 months, depending on the brand.
- Polio (inactivated): Four doses, starting at 2 months with the final dose between ages 4 and 6.
- Pneumococcal conjugate: Four doses between 2 and 15 months. Protects against pneumonia, ear infections, and bloodstream infections caused by pneumococcal bacteria.
- MMR (measles, mumps, rubella): First dose at 12 months, second dose at 15 months or between ages 4 and 6.
- Varicella (chickenpox): First dose around 12 to 15 months, second dose later in childhood or the teen years.
Most of these require multiple doses spaced weeks or months apart because a single shot isn’t enough to build lasting immunity in a developing immune system. Missing a dose doesn’t mean starting over. Pediatricians can adjust the timing to get back on track.
Vaccines for Preteens and Teens
The 11-to-12-year-old checkup is a key vaccination visit. Three vaccines are routinely given at this age:
Tdap replaces the childhood DTaP series with a single adolescent booster against tetanus, diphtheria, and whooping cough. This is the last scheduled dose before the every-10-years adult booster cycle begins.
HPV vaccine protects against the strains of human papillomavirus that cause cervical, throat, and other cancers. It’s recommended for both boys and girls starting at age 11 or 12, though it can be given as early as 9. Two doses, spaced six months apart, are sufficient when the series starts before age 15. Starting at 15 or later requires three doses. Catch-up vaccination is available through age 26 for anyone who missed it.
Meningococcal ACWY guards against four strains of bacterial meningitis. The first dose goes at age 11 or 12, with a booster at 16. That booster is important: protection fades, and the highest-risk years are the late teens. If the first dose was given between 13 and 15, the booster should follow at 16 to 18. If the first dose was at 16 or later, no booster is needed.
A separate meningococcal B vaccine is available but not universally recommended. It’s offered through shared decision-making, typically for teens aged 16 to 18 heading to college. Students wanting faster protection before move-in can receive an accelerated three-dose series.
Vaccines Every Adult Needs
Adults often assume they’re “done” with vaccines after childhood, but several remain important throughout life.
Flu (influenza): One dose every year, recommended for everyone 6 months and older. The virus mutates constantly, so last year’s shot won’t match this year’s strains.
COVID-19: Updated vaccines are released annually. Adults 19 to 26 need at least one dose of the current season’s formula. Adults 27 and older may need two or more doses depending on their vaccination history.
Tetanus/diphtheria booster: Every 10 years for all adults. If you’ve never had a Tdap dose as an adult, your next booster should be Tdap rather than Td, so you get refreshed whooping cough protection. After that, either version works for subsequent boosters. Any time you get a deep or dirty wound, a booster may be given regardless of the 10-year schedule.
Vaccines Added at 50 and Beyond
Three vaccines become relevant as you move into your 50s, 60s, and 70s, because aging weakens the immune system’s ability to fight certain infections.
Shingles (Shingrix)
Recommended for all adults 50 and older, given as two doses separated by two to six months. Shingles is a painful reactivation of the chickenpox virus that lies dormant in nerve tissue. In clinical trials, Shingrix was 91% effective at preventing postherpetic neuralgia, the lingering nerve pain that is shingles’ most debilitating complication. Even in adults 70 and older, effectiveness stayed at 89%. Adults 19 and older with weakened immune systems also qualify, with a shorter interval of one to two months between doses if needed.
Pneumococcal Vaccine
Pneumococcal disease causes pneumonia, bloodstream infections, and meningitis, and it’s especially dangerous for older adults. A pneumococcal conjugate vaccine is recommended for adults 50 and older who have never received one, and for adults 19 to 49 with chronic conditions like heart disease, diabetes, or lung disease. Several formulations are available (PCV15, PCV20, PCV21). If you receive PCV15, a follow-up dose of a different pneumococcal vaccine is recommended. PCV20 or PCV21 can be given alone.
RSV Vaccine
Respiratory syncytial virus causes thousands of hospitalizations in older adults each year. A single dose of RSV vaccine is recommended for all adults 75 and older. Adults 50 to 74 qualify if they have chronic conditions, weakened immune systems, or other factors that raise their risk of severe illness, including living in remote areas where emergency care is hard to reach.
Vaccines During Pregnancy
Two vaccines are specifically timed during pregnancy to pass protective antibodies to the baby before birth.
Tdap is given during each pregnancy, regardless of when the mother last had a booster. The ideal window is the early third trimester, so antibodies against whooping cough transfer to the baby before delivery. Whooping cough can be life-threatening for newborns too young to be vaccinated themselves.
RSV vaccine is recommended as a single dose between weeks 32 and 36 of pregnancy, during RSV season (September through January). Getting it after 36 weeks and 6 days is not recommended because there isn’t enough time for antibodies to develop and cross the placenta. This vaccine can be given at the same visit as Tdap, flu, or COVID-19 vaccines.
Vaccines for International Travel
Some vaccines are necessary only if you’re traveling to specific regions. A few countries require proof of vaccination for entry. The most common travel vaccines include protection against yellow fever, hepatitis A, typhoid fever, Japanese encephalitis, rabies, cholera, meningococcal disease, and tick-borne encephalitis. Yellow fever certification is the most frequently required at borders, particularly for travel to parts of sub-Saharan Africa and South America. Meningococcal vaccination is mandatory for pilgrims traveling to certain religious gatherings.
Which travel vaccines you need depends on your destination, the length of your trip, and what activities you’ll be doing. A travel health consultation four to six weeks before departure gives enough time for most vaccine series to take effect.
What Counts as “Necessary”
Very few vaccines are legally required in the United States. Most states mandate certain childhood vaccines for school enrollment, though exemption policies vary. For adults, no vaccines are federally required for daily life, but employers, colleges, and healthcare facilities often have their own policies. Military service, healthcare work, and international travel each come with specific requirements.
From a medical standpoint, the full set of recommended vaccines listed above is considered necessary for the best protection against preventable disease. Skipping or delaying vaccines doesn’t just affect individual risk. Diseases like measles and whooping cough spread quickly in communities with low vaccination rates, putting infants and people with weakened immune systems in danger. The recommended schedules are designed to provide protection at the ages when each disease poses the greatest threat.