Residency · Residency · Preventive Medicine
Adult Immunization Strategies and Catch-Up Schedules
Overview
Adult vaccination rates in the U.S. are significantly below Healthy People 2030 targets for most vaccines. Only ~50% of adults receive annual influenza vaccine; pneumococcal, shingles, and Tdap coverage remain suboptimal. ACIP (Advisory Committee on Immunization Practices) provides evidence-based recommendations for adult immunizations. New vaccines (RSV, updated COVID-19, updated pneumococcal) have expanded the adult immunization landscape. Preventive medicine physicians must be proficient in catch-up schedules, contraindications, and immunization for special populations (immunocompromised, pregnant, travelers)
ACIP Adult Immunization Schedule (Key Vaccines)
Influenza
Annual vaccination for all adults >=6 months (including pregnant women) Standard-dose inactivated (IIV4), recombinant (RIV4), or live attenuated (LAIV4, ages 2-49, non-pregnant) High-dose (Fluzone High-Dose) or adjuvanted (Fluad) preferred for adults >=65. Effectiveness varies by season (10-60%); greatest benefit in preventing severe illness and hospitalization.
Tdap/Td
One dose Tdap for all adults who have not previously received it (regardless of interval since last Td) Td or Tdap booster every 10 years. Tdap during each pregnancy (27-36 weeks) Wound management: Tdap preferred if not previously received; Td acceptable for boost.
MMR
Adults born in 1957 or later without evidence of immunity: 1 dose MMR. Two doses for healthcare workers, international travelers, and students at post-secondary institutions. Contraindicated in pregnancy and severe immunodeficiency. Evidence of immunity: documented vaccination, laboratory confirmation, or birth before 1957.
Varicella
Two doses (4-8 weeks apart) for adults without evidence of immunity. Evidence of immunity: 2 documented doses, lab confirmation, U.S.-born before 1980 (except healthcare workers and pregnant women), or history of disease. Contraindicated in pregnancy and severe immunodeficiency (live vaccine)
HPV (Gardasil 9)
Routine: ages 11-12 (2-dose series if started before age 15; 3-dose if started at >=15) Catch-up: through age 26 for all. Shared clinical decision-making: ages 27-45 (not routine; limited benefit if prior exposure) Not recommended after age 45. Contraindicated in pregnancy (defer doses until postpartum)
Pneumococcal
PCV20 (Prevnar 20): one dose for all adults >=65 and adults 19-64 with risk factors. Alternative: PCV15 followed by PPSV23 (>=1 year later) Risk conditions: chronic heart/lung/liver disease, diabetes, alcoholism, smoking, cochlear implant, CSF leak, immunocompromising conditions, asplenia, sickle cell. Simplified in 2023: PCV20 alone is preferred (replaces complex prior sequencing)
Shingles (Recombinant Zoster Vaccine -- Shingrix)
Two doses (2-6 months apart) for all adults >=50. Also recommended for immunocompromised adults >=19. ~97% efficacy against shingles at age 50-69; ~91% at >=70; efficacy sustained through 10+ years. Replaces live zoster vaccine (Zostavax), which was discontinued. Can be given regardless of prior history of shingles or Zostavax vaccination.
COVID-19
Updated (variant-adapted) COVID-19 vaccine recommended annually for all adults >=6 months. Additional doses for immunocompromised individuals. mRNA (Pfizer, Moderna) or protein subunit (Novavax) options. Schedule varies by prior vaccination history and immune status.
RSV
RSV vaccine (Abrysvo or Arexvy) for adults >=60 through shared clinical decision-making. Single dose; targets RSV seasons. Also approved for pregnant women at 32-36 weeks (Abrysvo) to prevent infant RSV.
Hepatitis B
Universal vaccination for all adults 19-59 (2022 ACIP update) Adults >=60: shared clinical decision-making (with risk factor-based recommendation) Options: Engerix-B/Recombivax HB (3-dose), Heplisav-B (2-dose, ages >=18), PreHevbrio (3-dose) Heplisav-B: higher seroconversion rates, especially in immunocompromised and older adults.
Hepatitis A
Not universally recommended for all adults (unlike HepB) Recommended for: travelers to endemic areas, MSM, persons who use drugs, persons with chronic liver disease, persons experiencing homelessness, HIV-positive individuals. Two-dose series (0, 6-12 months) or combination HepA-HepB (Twinrix, 3-dose)
Meningococcal
MenACWY: routine for first-year college students living in dorms (if not previously vaccinated at >=16); recommended for asplenia, complement deficiency, HIV, travel to meningitis belt. MenB: shared clinical decision-making for ages 16-23 (preferred 16-18); recommended for asplenia, complement deficiency, outbreak settings. Pentavalent MenABCDWY (Penbraya): FDA-approved 2023; single-product coverage of all five serogroups.
| Vaccine | Target Population | Schedule | Key Notes |
|---|---|---|---|
| Influenza | All adults annually | 1 dose/year | High-dose or adjuvanted preferred for ≥65 |
| Tdap/Td | All adults; each pregnancy | Tdap ×1, then Td/Tdap q10yr; Tdap 27-36 wks each pregnancy | Wound management: Tdap if not previously received |
| PCV20 | Adults ≥65; 19-64 with risk | 1 dose | Preferred over PCV15 + PPSV23 sequence |
| Shingrix (RZV) | Adults ≥50; immunocompromised ≥19 | 2 doses (0, 2-6 months) | ~97% efficacy ages 50-69; non-live |
| HPV (Gardasil 9) | Through age 26 (routine); 27-45 (shared decision) | 2-dose (<15) or 3-dose (≥15) | Not recommended after 45 |
| Hepatitis B | All adults 19-59; ≥60 shared decision | 2-dose (Heplisav-B) or 3-dose | Universal adult recommendation since 2022 |
| COVID-19 | All adults annually | Updated variant-adapted dose | Additional doses for immunocompromised |
| RSV | Adults ≥60 (shared decision); pregnant 32-36 wks | 1 dose | Abrysvo for both adult and maternal indications |
| MenACWY | College students; asplenia; complement deficiency | 2 doses (booster at 16) | Travel to meningitis belt |
| MenB | Ages 16-23 (shared decision); asplenia | 2 or 3 doses (product-dependent) | Pentavalent MenABCDWY now available |
Special Populations
Immunocompromised Patients
Avoid live vaccines: MMR, varicella, LAIV, live zoster (Zostavax) Shingrix (recombinant, non-live) IS recommended for immunocompromised adults >=19. Additional pneumococcal and meningococcal doses may be needed. COVID-19: additional primary and booster doses recommended. Hepatitis B: check anti-HBs titers after vaccination; Heplisav-B may provide better response. Timing: ideally vaccinate before immunosuppression; if on immunosuppressive therapy, response may be blunted.
Pregnant Women
Recommended: Tdap (27-36 weeks each pregnancy), inactivated influenza, COVID-19, RSV (Abrysvo, 32-36 weeks seasonal) Contraindicated: live vaccines (MMR, varicella, LAIV, live zoster); HPV (defer) If indicated: Hepatitis A, Hepatitis B, pneumococcal, meningococcal (inactivated) are safe.
Healthcare Workers
Required/strongly recommended: annual influenza, Tdap, MMR (2 doses), varicella (2 doses or titer), Hepatitis B (with titer confirmation) COVID-19: per facility policy. TB screening: per occupational health protocol.
Travelers
Destination-specific: yellow fever (live vaccine), typhoid, Japanese encephalitis, rabies pre-exposure, meningococcal (meningitis belt) Routine catch-up: ensure all age-appropriate vaccines are current. Hepatitis A: for all travelers to endemic areas. Malaria chemoprophylaxis (not a vaccine): separate consideration.
<image>A comprehensive adult immunization schedule chart organized by vaccine (rows) and age group (columns: 19-26, 27-49, 50-64, >=65). Each cell is color-coded: green for routine recommendation, yellow for shared clinical decision-making, orange for risk-based, and red for contraindicated. Vaccines include influenza, Tdap, MMR, varicella, HPV, PCV20, Shingrix, COVID-19, RSV, HepB, HepA, and meningococcal. Adult immunization schedule education illustration.</image>
<image>A flowchart for pneumococcal vaccination in adults showing two pathways: (1) PCV20 alone (preferred, one dose) or (2) PCV15 followed by PPSV23 (>=1 year later). Entry criteria branch into adults >=65 (routine) and adults 19-64 with risk conditions (list provided). Previously vaccinated individuals have a separate pathway showing how to complete the series. Pneumococcal vaccination algorithm education illustration.</image>
<image>An infographic showing adult vaccination coverage rates compared to Healthy People 2030 targets for key vaccines: influenza (~50% vs. 70% target), Tdap (~40% vs. 90%), shingles >=50 (~35% vs. 50%), pneumococcal >=65 (~65% vs. 90%), and HPV series completion ages 19-26 (~60% vs. 80%). Bars show the gap between current coverage and targets, with annotations about disparities by race, insurance status, and geography. Adult immunization coverage education illustration.</image>
Clinical Pearls
Shingrix is a recombinant (non-live) vaccine and CAN be given to immunocompromised patients -- this is a common point of confusion; Zostavax (live) was contraindicated, but Shingrix is specifically recommended for immunocompromised adults >=19. PCV20 has simplified pneumococcal vaccination -- one dose for adults >=65 or those 19-64 with risk conditions replaces the complex prior PCV13/PPSV23 sequencing. HPV vaccination through shared clinical decision-making for ages 27-45 is generally of limited benefit -- most adults in this range have already been exposed to vaccine-type HPV; the greatest population benefit comes from vaccinating at ages 11-12. For boards: know the adult schedule by age group, live vaccine contraindications (pregnancy, immunocompromised), the pneumococcal algorithm, and Tdap timing in pregnancy (27-36 weeks each pregnancy) Adult vaccination rates remain far below targets for most vaccines -- systems-level interventions (standing orders, EHR reminders, pharmacist-administered vaccines) are more effective than clinician reminders alone.
References
- CDC. Recommended Adult Immunization Schedule, United States, 2024-2025. MMWR. 2024.
- Dooling KL, et al. Recommendations of the Advisory Committee on Immunization Practices for use of recombinant zoster vaccine. MMWR. 2018;67(3):103-108.
- Kobayashi M, et al. Use of 15-valent and 20-valent pneumococcal conjugate vaccines among U.S. adults: ACIP recommendations. MMWR. 2023;72(RR-3):1-39.
- Meites E, et al. Human papillomavirus vaccination for adults: ACIP recommendations. MMWR. 2019;68(32):698-702.
- Lu PJ, et al. Surveillance of vaccination coverage among adult populations -- United States, 2022. MMWR Surveill Summ. 2023.
How to think about this
Adult immunization can feel overwhelming given the growing number of recommended vaccines and nuanced schedules. Rather than memorizing every detail, focus on understanding the underlying principles that guide ACIP recommendations. This includes prioritizing vaccines based on disease burden, individual risk factors (age, comorbidities, lifestyle), and public health impact. Recognize the shift towards simplifying schedules, such as with PCV20 for pneumococcal disease, and the increasing role of shared clinical decision-making for certain vaccines like HPV in older adults or RSV. Critically evaluate whether a vaccine is live or inactivated, as this dictates its use in vulnerable populations like pregnant or immunocompromised patients.
Check yourself with 2 bullets.
- What are the key considerations when deciding whether to give a live vaccine?
- How has the approach to pneumococcal vaccination for adults changed recently, and what is the primary advantage of the new recommendation?
