What is the recommended immunization schedule for a healthy 19‑year‑old adult with no known contraindications?

Immunization Schedule for a Healthy 19-Year-Old Adult

A healthy 19-year-old with no immunization records should receive a comprehensive catch-up vaccination series including Tdap, annual influenza vaccine, MMR (2 doses), varicella (2 doses), HPV (3 doses), hepatitis B (2-3 doses), and meningococcal vaccines, with the approach being to vaccinate rather than test for immunity. 1

Core Principle: Vaccinate, Don't Wait

• When vaccination records are unavailable, assume the patient is unvaccinated and administer all age-appropriate vaccines immediately without serologic testing, as giving extra doses to previously immunized individuals poses no additional risk. 1
• Do not delay vaccination while attempting to locate records or perform antibody testing—protection takes priority over theoretical concerns about redundant vaccination. 1

Universal Vaccines for All 19-Year-Olds

Tetanus-Diphtheria-Pertussis (Tdap/Td)

• Administer a complete 3-dose primary series: first two doses at least 4 weeks apart, third dose 6-12 months after the second dose. 1
• After completing the primary series, give Td boosters every 10 years. 1

Influenza

• Give one annual dose of inactivated influenza vaccine (IIV) or recombinant influenza vaccine (RIV). 2
• Live attenuated influenza vaccine (LAIV) is an option for healthy adults aged ≤49 years. 2

Measles-Mumps-Rubella (MMR)

• Administer a 2-dose series spaced at least 4 weeks apart for anyone born in 1957 or later without documentation of vaccination, physician-diagnosed disease, or laboratory immunity. 1
• Two doses are required regardless of birth year if the patient will work in healthcare. 1

Varicella

• Give a 2-dose series 4-8 weeks apart when no evidence of immunity exists (U.S. birth before 1980 does not count as evidence for healthcare workers). 1
• Serologic testing may be considered only for varicella if history is uncertain, but vaccination without testing is acceptable. 1

Human Papillomavirus (HPV)

• Administer a 3-dose series at 0,1-2, and 6 months for both males and females through age 26 years. 2, 1
• For males specifically, routine vaccination is recommended through age 21, with catch-up through age 26. 2, 1
• The 3-dose schedule applies because the patient did not start the series before age 15 years. 2

Hepatitis B

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

Risk-Based Vaccines to Assess

Hepatitis A

• Administer a 2-dose series if the patient has any of these risk factors: 2, 1
  • Men who have sex with men
  • Injection or non-injection drug use
  • Chronic liver disease
  • Homelessness
  • Travel to endemic regions
  • Close contact with international adoptees
• Any person who wants protection against hepatitis A may be vaccinated even without risk factors. 2

Meningococcal Vaccines (MenACWY and MenB)

• Give MenACWY if the patient lives in college dormitories or military barracks, has functional or anatomic asplenia, or is a microbiologist routinely exposed to Neisseria meningitidis. 1
• Consider MenB for healthy young adults aged 16-23 years (preferred 16-18) based on individual clinical decision: give either a 2-dose MenB-4C series ≥1 month apart or MenB-FHbp at 0 and 6 months (the two products are not interchangeable). 2, 1

Critical Implementation Points

Timing and Spacing

• Live vaccines (MMR, varicella, LAIV) can be given on the same day or must be separated by at least 4 weeks. 1
• Inactivated vaccines can be given simultaneously or at any interval. 1

Special Populations

• If the patient is pregnant or planning pregnancy, defer MMR, varicella, and LAIV until postpartum, as all live vaccines are contraindicated in pregnancy. 1, 3
• If the patient is immunocompromised, complete all indicated vaccines at least 2 weeks before starting immunosuppressive therapy when possible, and defer live vaccines until immune function recovers. 1

Documentation Requirements

• Immunization records or laboratory evidence—not patient recall—are required to confirm immunity before withholding vaccines. 1
• Document all vaccines administered with dates, manufacturer, lot numbers, and anatomic site. 1

Common Pitfalls to Avoid

• Do not accept patient recall of childhood vaccinations as evidence of immunity—only written documentation or laboratory confirmation counts. 1
• Do not delay HPV vaccination because the patient is 19 years old—catch-up vaccination is recommended through age 26 for both males and females. 2, 1
• Do not assume that a healthy 19-year-old doesn't need meningococcal vaccines—assess for college dormitory residence or other risk factors. 1
• Do not give only one dose of MMR or varicella—both require 2 doses for adequate protection. 1