What are the catch-up vaccination guidelines for adults who never received vaccinations as a child?

Catch-Up Vaccination Guidelines for Unvaccinated Adults

Adults who never received childhood vaccinations should follow the adult immunization schedule and receive all age-appropriate vaccines immediately without needing to restart any series, regardless of time elapsed between doses. 1

Core Principle: Never Restart a Series

The most critical principle is that vaccine series do not need to be restarted, regardless of how much time has elapsed between doses or vaccine type. 1 This means if an adult received any childhood vaccines but never completed the series, they simply continue from where they left off rather than starting over.

Essential Vaccines for Previously Unvaccinated Adults

Immediate Priority Vaccines

• Tdap (Tetanus, Diphtheria, Pertussis): Administer one dose of Tdap immediately, followed by Td or Tdap boosters every 10 years thereafter. 1

• MMR (Measles, Mumps, Rubella): Administer 2 doses at least 4 weeks apart for adults born in 1980 or later with no evidence of immunity. 1

• Varicella: Administer 2 doses 4-8 weeks apart for adults with no evidence of immunity (no history of chickenpox or shingles, no prior vaccination, and no laboratory confirmation of immunity). 1

• Hepatitis B: Complete a 3-dose series (0,1-2 months, 6 months schedule). 2, 3

• Hepatitis A: Complete a 2-dose series with doses separated by at least 6 months. 1, 2

Age-Specific Vaccines

• HPV (Human Papillomavirus): For adults through age 26 who were not previously vaccinated, administer a 2- or 3-dose series depending on age at initiation. 4

• Meningococcal ACWY: Consider for adults with specific risk factors (complement deficiency, asplenia, microbiologists, or during outbreaks). 1, 2

• Pneumococcal vaccines: Follow age-based and risk-based recommendations, with PCV13 followed by PPSV23 for immunocompromised individuals, or PPSV23 alone for adults ≥65 years or those with chronic conditions. 1

• Zoster (Shingles): Administer 2-dose series of RZV (Shingrix) 2-6 months apart for adults ≥50 years, regardless of prior history of shingles. 1

Annual Vaccines

• Influenza: Administer annually, every year. 2, 4

Key Implementation Strategies

Simultaneous Administration

All indicated vaccines should be administered simultaneously at separate injection sites during the same visit. 1 This approach is critical because:

• It increases the probability that adults will be fully immunized 1
• It reduces the risk of patients not returning for subsequent doses 5
• There are no safety concerns with simultaneous administration of multiple vaccines 1

Accelerated Schedules When Needed

• Minimum intervals between doses can be used when rapid catch-up is needed (such as before international travel), but doses should never be administered earlier than the minimum intervals specified in catch-up schedules. 1

• Doses administered ≥4 days before the minimum interval can be counted as valid, but doses given ≥5 days early must be repeated. 1

Common Pitfalls to Avoid

Do Not Delay Vaccination

The goal is to immunize as soon as possible, before exposure to infectious organisms. 1 Waiting for "the right time" or spreading vaccines out unnecessarily increases the window of vulnerability to vaccine-preventable diseases. 6

Do Not Confuse Contraindications

• Very few true contraindications exist for vaccination. 6
• Pregnancy is NOT a contraindication for most inactivated vaccines (including Tdap, which is recommended during each pregnancy). 1
• Live vaccines (MMR, varicella, zoster live vaccine) are contraindicated in pregnancy and severe immunocompromising conditions, but RZV (recombinant zoster vaccine) may be used in some immunocompromised patients. 1, 3

Special Populations Requiring Modified Schedules

• Healthcare personnel: Must have documented evidence of immunity to varicella regardless of birth year, requiring 2 doses if no prior vaccination. 1

• Immunocompromised adults: Require modified schedules with additional doses of pneumococcal vaccines and should avoid live vaccines. 1, 3

• Pregnant women: Should receive Tdap during each pregnancy (preferably 27-36 weeks gestation) and can receive most inactivated vaccines if otherwise indicated. 1

Documentation and Follow-Up

• Maintain accurate vaccination records to track which vaccines have been administered and which remain outstanding. 2
• Schedule follow-up appointments immediately to ensure completion of multi-dose series. 5
• Use reminder systems to prevent patients from falling off schedule for subsequent doses. 6