What is the recommended vaccine schedule for a healthy 19‑year‑old adult living in the United States who has no documented immunization record?

Recommended Immunization Schedule for a 19-Year-Old Without Documentation

A healthy 19-year-old in the United States without immunization records should be assumed unvaccinated and receive all age-appropriate vaccines immediately without waiting for serologic testing, as administering vaccines to previously immunized individuals poses no additional risk. 1

Core Vaccines Required for All 19-Year-Olds

Tetanus, Diphtheria, and Pertussis (Tdap/Td)

• Administer one dose of Tdap immediately, followed by Td boosters at 4 weeks and 6-12 months to complete the primary 3-dose series. 1
• After completing the primary series, give Td boosters every 10 years. 2

Influenza

• Give one dose of inactivated influenza vaccine (IIV) or live attenuated influenza vaccine (LAIV) annually. 2
• This is recommended for all adults regardless of age or risk factors. 1

Hepatitis B

• Administer a 2-dose series of HEPLISAV-B at 0 and 1 month, or a 3-dose series of ENGERIX-B/Recombivax HB at 0,1, and 6 months. 1
• Universal hepatitis B vaccination is now recommended for all adults aged 19-59 years. 1

Measles, Mumps, and Rubella (MMR)

• Give a 2-dose series of MMR at least 4 weeks apart if born in 1957 or later without documentation of vaccination or laboratory immunity. 2, 1
• Two doses are required for healthcare workers and other high-risk adults; one dose may suffice for average-risk individuals. 1

Varicella

• Administer a 2-dose series of varicella vaccine 4-8 weeks apart if no evidence of immunity exists. 2
• Evidence of immunity includes U.S. birth before 1980 (except for healthcare personnel), documentation of vaccination, laboratory confirmation, or physician-diagnosed disease. 2

Human Papillomavirus (HPV)

• Give a 3-dose series of HPV vaccine at 0,1-2, and 6 months for both males and females through age 26 years. 2
• For males specifically, the schedule shows 3 doses through age 21 years as routine, with catch-up through age 26. 2

Risk-Based Vaccines to Assess

Hepatitis A

• Administer a 2-dose series if the patient has any of these risk factors: 2
  • Men who have sex with men
  • Injection or non-injection drug use
  • Chronic liver disease
  • Homelessness
  • Travel to endemic countries
  • Close contact with international adoptees from endemic areas

Meningococcal Vaccines

• Give meningococcal conjugate vaccine (MenACWY) if the patient: 2

  • Lives in college dormitories or military barracks
  • Has functional or anatomic asplenia
  • Has complement deficiencies or HIV infection
  • Is a microbiologist routinely exposed to Neisseria meningitidis
  • Travels to hyperendemic areas

• Consider meningococcal B vaccine (MenB) based on individual clinical decision for healthy adolescents and young adults aged 16-23 years (preferred age 16-18). 2

  • Give 2-dose series of MenB-4C at least 1 month apart, or MenB-FHbp at 0 and 6 months. 2
  • The two MenB products are not interchangeable. 2

Critical Implementation Points

Approach to Missing Records

• Never delay vaccination to search for records or obtain serologic testing for most vaccines. 1
• The standard approach is to administer all indicated vaccines immediately, as giving extra doses to previously immune individuals is safe. 1
• The only exception where serology may be considered is for varicella in adults with uncertain history, but vaccination without testing is still acceptable. 2

Vaccine Administration

• All indicated vaccines can be administered simultaneously at the same visit. 3
• Use separate anatomic sites for different injections. 3
• Minimum intervals between doses must be respected, but longer intervals do not reduce effectiveness. 3

Common Pitfalls to Avoid

• Do not restart vaccine series regardless of time elapsed between doses—simply continue where the patient left off. 3
• Do not withhold vaccines while attempting to locate old records—this delays protection unnecessarily. 1
• Do not assume immunity based on patient recall alone—documentation or laboratory evidence is required. 2
• Do not give live vaccines (MMR, varicella, LAIV) to pregnant women or severely immunocompromised patients. 2

Special Considerations for This Age Group

• If the patient is a healthcare worker, ensure 2 doses of MMR and varicella regardless of birth year. 2
• If the patient is or becomes pregnant, administer Tdap during each pregnancy at 27-36 weeks gestation. 2, 3
• If the patient has any immunocompromising conditions, complete all indicated vaccines at least 2 weeks before starting immunosuppressive therapy when possible. 1