Human Development

Routine pediatric immunizations: CDC schedule and catch-up

Clinical Overview and When to Suspect Under-Immunization

— Foreign-born child, refugee, recent international adoption (assume unimmunized unless written records in WHO-recognized format)

— Homeschooled or religiously exempted children presenting for sports physicals, college entry, or post-exposure care

— Children with prolonged hospitalizations, NICU graduates discharged off-schedule, or those with chronic illness whose vaccines were "held"

— Foster care intake, adolescent well-visit where prior records are fragmented

Scope: The CDC/ACIP childhood and adolescent immunization schedule is updated annually and represents the US standard of care from birth through age 18. Step 3 testing focuses on age-appropriate dosing, catch-up logic, contraindications vs precautions, and counseling vaccine-hesitant families.

Routine antigens covered birth–18 y: HepB, RV, DTaP/Tdap, Hib, PCV15/20, IPV, influenza, MMR, VAR, HepA, HPV, MenACWY, MenB, COVID-19, RSV (nirsevimab passive immunization).

When to suspect under-immunization:

Step 3 management: At every encounter—well-child, urgent care, ED follow-up, pre-op—review the immunization record and offer due/overdue doses simultaneously. Missed opportunities (giving only one vaccine when several are due) are a quality measure failure.

Documentation: Per the National Childhood Vaccine Injury Act, you must record vaccine name, manufacturer, lot #, date, site, route, VIS edition date, and administrator signature. Provide the Vaccine Information Statement (VIS) before each dose.

Board pearl: Mild illness, low-grade fever, antibiotic use, breastfeeding, prematurity, and recent exposure to infection are NOT contraindications. Withholding vaccines for these reasons is a classic wrong-answer trap.

Funding safety net: Vaccines for Children (VFC) program covers Medicaid-eligible, uninsured, underinsured, and AI/AN children through age 18—removing cost as a barrier.

Presentation Patterns and Key History

— 2-, 4-, 6-month well-child visit: which vaccines are due today?

— 11–12 y adolescent visit: Tdap, HPV, MenACWY (#1), influenza

— 16 y visit: MenACWY booster, MenB shared decision-making

— Catch-up scenario: 7-year-old immigrant with no records

— Pre-kindergarten (4–6 y): DTaP #5, IPV #4, MMR #2, VAR #2

— Birth history: HepB at birth? Maternal HBsAg status? Gestational age (affects RSV/nirsevimab eligibility, HepB dosing in <2 kg infants—delay until 1 month or hospital discharge)

— Prior reactions: anaphylaxis to vaccine component (egg, gelatin, neomycin, yeast), encephalopathy within 7 days of pertussis vaccine, intussusception (rotavirus precaution)

— Immunocompromise: primary immunodeficiency, HIV with low CD4, chemotherapy, high-dose steroids (≥2 mg/kg/day or ≥20 mg/day prednisone for ≥14 days), biologics, post-HSCT

— Household contacts: pregnant women, immunocompromised persons → still give live vaccines to the child (MMR, VAR, RV) but avoid contact with rash if it develops

— Travel plans: may accelerate MMR (give at 6–11 mo, doesn't count toward series) or HepA

— Pregnancy in adolescent: defer live vaccines (MMR, VAR, HPV technically defer, LAIV)

Typical exam vignettes:

History must capture:

Key distinction: Contraindication = do not give (anaphylaxis to prior dose/component; severe combined immunodeficiency for live vaccines; encephalopathy within 7 days of DTaP unrelated to other cause). Precaution = weigh risk/benefit (moderate-severe acute illness with fever, Guillain-Barré within 6 weeks of prior tetanus-containing vaccine, progressive neurologic disorder for DTaP).

Board pearl: Egg allergy of any severity is no longer a contraindication to influenza vaccine—give any age-appropriate flu vaccine in the usual setting.

Counseling: Use presumptive language ("Sara is due for three shots today") rather than participatory ("What do you want to do?")—evidence shows higher uptake and is the ACIP-endorsed communication strategy.

Physical Exam Findings and Pre-Vaccination Assessment

— Is the child sick today? (moderate/severe illness = defer)

— Any allergies to medications, food, or prior vaccines?

— Any reaction to a previous vaccine?

— Immunocompromise in child or household? Recent blood products?

— Temperature ≥38.5°C with systemic illness → defer

— Low-grade fever, URI, otitis media, mild diarrhea → proceed

— Inspect injection sites: deltoid for ≥12 months and toddlers/older; anterolateral thigh (vastus lateralis) for infants <12 months

— Document any active eczema, dermatitis—affects site selection, not vaccine eligibility

— Assess developmental milestones at well-visits; vaccines do not cause autism—reaffirm with families if asked

— Anatomic or functional asplenia (sickle cell disease, post-splenectomy, congenital): add PCV20 + PPSV23, MenACWY starting at 2 months (use infant schedule), MenB at ≥10 y, Hib if unvaccinated

— Cochlear implant or CSF leak: PCV20 + PPSV23

— Severe combined immunodeficiency or known T-cell defect: avoid all live vaccines (MMR, VAR, LAIV, RV, yellow fever, BCG)

— Active cancer on chemo: hold live vaccines; inactivated vaccines acceptable but suboptimal response—revaccinate ≥3 months after chemo completion

— IM vaccines: 22–25 gauge, 1-inch needle for infants, 1–1.5 inch for older children/adolescents

— Aspiration before injection is not required per ACIP

— Multiple vaccines: separate sites by ≥1 inch; document each site

Pre-vaccine screening at every visit (4 questions):

Vital signs that matter:

Exam pearls:

Special physical findings altering plan:

Injection technique safety:

CCS pearl: Before ordering vaccines on the CCS, order "counsel patient/parent on vaccine," "vaccine information statement," and document observation for 15 minutes post-injection (longer if prior vasovagal or allergy history)—syncope is most common in adolescents post-HPV/MenACWY/Tdap; have them seated or supine.

Diagnostic Workup — Records Review and Serology

— State immunization information system (IIS) registry

— Prior pediatrician, school, WIC, military, or international yellow card (WHO format)

— Self-report alone is not acceptable for childhood vaccines except influenza and PPSV in adults

— Default rule: "When in doubt, vaccinate." Extra doses of most vaccines are not harmful.

— Exceptions where titers may be cost-effective: internationally adopted children where parents prefer fewer injections, or where vaccine cost/availability is limiting

— HepB: anti-HBs ≥10 mIU/mL = immune; HBsAg + anti-HBc to screen for chronic infection (high yield in international adoptees)

— MMR: measles IgG, mumps IgG, rubella IgG

— Varicella: VZV IgG

— Hepatitis A: total anti-HAV

— Polio, Hib, pertussis, pneumococcal: titer testing not recommended routinely—just vaccinate per catch-up

— Live vaccines (MMR, VAR) can suppress tuberculin reactivity for 4–6 weeks

— Place PPD/IGRA same day as live vaccine OR wait ≥4 weeks after

Step 1: Obtain authoritative records.

Step 2: Decide—catch up or check titers?

Useful serologic markers (when titer-testing is chosen):

Tuberculosis screening interaction:

Pregnancy testing in adolescents: Not required before HPV, but counsel to avoid pregnancy during series; if becomes pregnant, complete after delivery

Board pearl: Internationally adopted child <18 months from a country with high HepB prevalence → check HBsAg, anti-HBc, anti-HBs, plus HIV, syphilis, TB, stool O&P, CBC. Vaccinate per US schedule regardless of foreign records unless records meet ACIP standards (written, dates with day/month/year, intervals appropriate).

Key distinction: A vaccine dose given >4 days before the minimum age or minimum interval is invalid and must be repeated. The "4-day grace period" applies to most childhood vaccines but not to rabies or the HepB birth dose.

Diagnostic Workup — Catch-Up Schedule Logic

— Do not restart a series—count valid prior doses and continue

— Use the ACIP catch-up schedule (Table 2) for minimum ages and intervals

— Administer all needed vaccines at the same visit when possible

— HepB: 3-dose series anytime; minimum intervals 4 weeks (1→2), 8 weeks (2→3), 16 weeks total from dose 1; final dose ≥24 weeks of age

— Rotavirus: max age for dose 1 = 14 weeks 6 days; max age for final dose = 8 months 0 days; do NOT initiate after 15 weeks

— DTaP: 5 doses by age 6; if starting late, use catch-up intervals; switch to Tdap at age 7+

— Hib: complexity depends on age at first dose and product; not needed if healthy and ≥5 years (unless asplenia, HIV, post-HSCT)

— PCV: healthy children ≥5 y generally do not need catch-up; high-risk through age 18 need PCV20 ± PPSV23

— IPV: 4 doses; final dose ≥4 y and ≥6 mo after previous; not routinely given ≥18 y in US-born

— MMR: 2 doses ≥4 weeks apart, both after 12 months of age

— Varicella: 2 doses; if <13 y, interval ≥3 months; if ≥13 y, interval ≥4 weeks

— HepA: 2 doses ≥6 months apart

— HPV: 2 doses (0, 6–12 mo) if started age 9–14; 3 doses (0, 1–2, 6 mo) if started ≥15 y or immunocompromised

— MenACWY: 1 dose at 11–12, booster at 16; if first dose at 13–15, booster at 16–18; if first dose ≥16, no booster needed

General catch-up principles:

Catch-up by age—high-yield rules:

Step 3 management: A 5-year-old with only 3 DTaP doses and 2 IPV—give DTaP #4 today, IPV #3 today (or wait per intervals), schedule DTaP #5 and IPV #4 at age-appropriate times. Don't restart.

Board pearl: A child who turns 7 mid-DTaP series finishes with Tdap (not DTaP) for any remaining doses.

Risk Stratification and Decision Framework

— Tier 1 (routine, healthy): standard ACIP schedule

— Tier 2 (chronic disease): asthma, diabetes, CKD, chronic liver disease, CHD → add annual influenza, PCV20, HepA/HepB if not already covered

— Tier 3 (immunocompromised): HIV, malignancy, asplenia, complement deficiency, HSCT, solid organ transplant, primary immunodeficiency → expanded pneumococcal and meningococcal coverage; avoid live vaccines based on degree of immunosuppression

— MMR and varicella: give if CD4 ≥15% AND ≥200 cells/µL in adolescents; not severely immunosuppressed

— Avoid LAIV and rotavirus is contraindicated only in SCID; rotavirus is permissible in HIV-exposed infants

— MenACWY: start at 2 months (infant 4-dose schedule), boost every 5 years lifelong

— MenB: ≥10 years, then booster 1 year later, then every 2–3 years

— PCV20 + PPSV23 (PPSV23 8 weeks after PCV, repeat once 5 years later)

— Live vaccines: complete ≥4 weeks before immunosuppression

— Inactivated: complete ≥2 weeks before

— Post-HSCT: revaccinate fully starting 6–12 months post-transplant

Tiered vaccine groupings by medical risk:

HIV-specific logic:

Asplenia/complement deficiency:

Household contacts of immunocompromised: Give all routine vaccines including live—household varicella vaccine recipient with rash should cover lesions and avoid the immunocompromised contact until crusted.

Pre-transplant timing:

Key distinction: PCV15 vs PCV20—either is acceptable for the routine infant series (4 doses at 2, 4, 6, 12–15 mo). If PCV15 is used, follow with PPSV23 at 2 years for high-risk children; PCV20 obviates the need for PPSV23 in many high-risk groups.

Board pearl: Children with CSF leaks or cochlear implants need PCV + PPSV23 but not meningococcal vaccines (unlike asplenia/complement deficiency).

Pharmacotherapy — Routine Schedule Drug-by-Drug

— RSV: Nirsevimab monoclonal antibody for infants <8 mo entering first RSV season (or maternal RSVpreF vaccine at 32–36 weeks gestation Sept–Jan)

— Maternal Tdap at 27–36 weeks every pregnancy

— Maternal influenza any trimester

Birth: HepB #1 (monovalent, within 24 h; if mother HBsAg+, also give HBIG within 12 h)

2 months: HepB #2, RV #1, DTaP #1, Hib #1, PCV #1, IPV #1

4 months: RV #2, DTaP #2, Hib #2, PCV #2, IPV #2

6 months: HepB #3 (range 6–18 mo), RV #3 (if RotaTeq), DTaP #3, Hib #3 (if PRP-T), PCV #3, IPV #3 (range 6–18 mo), influenza annually starting at 6 mo, COVID-19 per current guidance

12–15 months: Hib #4, PCV #4, MMR #1, VAR #1, HepA #1

15–18 months: DTaP #4

18–23 months: HepA #2 (≥6 mo after #1)

4–6 years: DTaP #5, IPV #4, MMR #2, VAR #2

11–12 years: Tdap (1 dose), HPV (2- or 3-dose series), MenACWY #1

16 years: MenACWY booster; MenB shared clinical decision-making (16–23 y)

Annual: Influenza for all ≥6 months

Maternal/passive:

Live vaccines (memorize): MMR, VAR, MMRV, LAIV, rotavirus, yellow fever, BCG, oral typhoid, smallpox

Spacing rules between live vaccines: Give same day OR separate by ≥28 days. If given <28 days apart, the second is invalid—repeat ≥28 days later.

Antibody-containing products (IVIG, blood transfusion): delay MMR/VAR by 3–11 months depending on product/dose; conversely, avoid antibody products for 2 weeks after MMR/VAR

Board pearl: MMRV (ProQuad) at first dose (12–15 mo) doubles the risk of febrile seizure vs MMR + VAR separately—prefer separate injections for dose 1; MMRV acceptable for dose 2 at 4–6 y.

Procedures, Counseling, and Vaccine Hesitancy Management

— Multiple vaccines same visit: standard of care; no maximum number

— Combination vaccines (Pediarix, Pentacel, Vaxelis, Kinrix, ProQuad) reduce injections but cannot substitute for missing antigens—check what's inside

— Anatomic spacing: ≥1 inch apart, same limb acceptable if needed

— Breastfeeding, sucrose, swaddling for infants

— Topical lidocaine/prilocaine (EMLA) 30–60 min pre-injection

— Distraction, cough trick, vapocoolant in older children

— Prophylactic acetaminophen reduces antibody response—do not give pre-vaccine routinely; treat fever if it develops

— Corroborate parental concerns ("I hear you're worried about autism")

— About me ("I've studied this extensively")

— Science (cite Lancet retraction, large cohort data showing no MMR-autism link)

— Explain/advise ("I strongly recommend MMR today")

— Use motivational interviewing; avoid confrontation

— Document refusal with AAP Refusal to Vaccinate form; revisit at every visit

— HPV vaccine: minors can often consent in many states under minor consent for STI prevention statutes—know your state law

— Document discussion; bill appropriately

— VAERS (Vaccine Adverse Event Reporting System): report any clinically significant adverse event, mandatory for events listed on the Reportable Events Table

— VICP (Vaccine Injury Compensation Program): no-fault federal compensation; statute of limitations 3 years from first symptom

Administration logistics:

Pain reduction:

Vaccine hesitancy framework (CASE/AAP approach):

Adolescent confidentiality:

Reporting and safety:

CCS pearl: Post-injection, order observe 15 min; if syncope occurs, document, supine positioning, vitals. For anaphylaxis: IM epinephrine 0.01 mg/kg (max 0.3 mg) in mid-anterolateral thigh, call 911, oxygen, IV access, second dose in 5–15 min if needed.

Special Populations — Preterm, Low Birth Weight, and Medical Complexity

— Vaccinate by chronologic age, not corrected age, with the same doses (no dose reduction)

— HepB birth dose:

— Infant ≥2000 g and mother HBsAg-negative: give within 24 h as usual

— Infant <2000 g and mother HBsAg-negative: delay until 1 month chronologic age or hospital discharge (whichever first); this dose does not count toward the 3-dose series

— Mother HBsAg-positive or unknown: HepB + HBIG within 12 h regardless of weight; if <2000 g, give 4 total doses (birth, 1, 2–3, 6 mo)

— Rotavirus: can give in NICU at discharge if age-appropriate, but not while still hospitalized (shedding risk)

— Annual influenza ≥6 mo

— Nirsevimab/palivizumab for RSV per AAP criteria

— PCV + PPSV23 if eligible

— Inactivated vaccines safe but possibly less effective—check titers after series for HepB, MMR, VAR in selected cases

— Live vaccines: see prior chunk; revaccinate post-chemo/post-HSCT

— Complete all vaccines including live ≥4 weeks pre-transplant if possible

— Post-transplant: no live vaccines; inactivated only, starting 3–6 months post-transplant

— CKD/dialysis: high-dose HepB (40 mcg, double dose) and annual flu, PCV20

— Chronic liver disease: HepA + HepB strongly indicated

Preterm and low birth weight infants:

Chronic lung disease, CHD, Down syndrome:

Immunocompromised children:

Solid organ transplant candidates:

Renal/hepatic impairment:

Board pearl: Aspirin therapy in children (Kawasaki, rheumatic disease) is a precaution for varicella and LAIV due to Reye syndrome risk—use inactivated influenza vaccine and consider VAR risk/benefit individually.

Step 3 management: NICU graduate at 2-month birthday: give all 2-month vaccines on schedule including rotavirus if not still hospitalized; monitor for apnea in extremely preterm (<28 weeks) for 48 h after first immunizations.

Special Populations — Pregnancy, Adolescents, and International

— Recommended in pregnancy: Tdap (27–36 weeks every pregnancy), influenza (inactivated, any trimester), COVID-19, RSVpreF (32–36 weeks Sept–Jan)

— Contraindicated in pregnancy: MMR, varicella, LAIV, HPV (defer until postpartum, though inadvertent administration not an indication for termination)

— Postpartum: give MMR and varicella before discharge if non-immune; HPV can resume/start

— Verify HepB (3 doses), MMR (2), VAR (2), HepA (2), polio (4)

— Administer Tdap, HPV, MenACWY, annual flu, COVID-19, MenB shared decision

— HPV: 9-valent (Gardasil 9), 2 doses if <15 at start, 3 doses if ≥15 or immunocompromised

— Accelerate MMR: give at age 6–11 months for travel, then repeat 2 doses ≥12 months and ≥4 weeks apart (early dose doesn't count)

— HepA, typhoid, yellow fever (≥9 mo), Japanese encephalitis, meningococcal (Hajj), rabies pre-exposure as indicated

— Malaria chemoprophylaxis (not a vaccine but tested)

— Assume unvaccinated if no documentation; vaccinate per US catch-up schedule

— Screen: TB (IGRA ≥2 y or PPD), HIV, HepB, HepC, syphilis, lead, CBC, stool O&P

Pregnant adolescents:

Breastfeeding: Not a contraindication to any vaccine (mother or infant), including live vaccines (exception: yellow fever requires caution).

Adolescent-specific catch-up at 11–18 y:

International travelers (pediatric):

Refugees/internationally adopted:

Key distinction: HPV vaccine in pregnancy = not recommended, but not abortifacient—reassure and resume series postpartum. MMR/VAR in pregnancy = contraindicated but inadvertent administration is not an indication for termination; counsel and report to registry.

Board pearl: A previously unvaccinated adolescent immigrant ≥7 y needs Tdap (not DTaP) for catch-up tetanus series: Tdap, then Td or Tdap at 4 weeks, then Td or Tdap 6–12 months later (3 doses total).

Complications and Adverse Outcomes

— Local: pain, redness, swelling at site (resolves 1–2 days)

— Systemic: low-grade fever, fussiness, decreased appetite

— MMR/VAR: fever and rash 7–14 days post-vaccine; mild

— DTaP: fever ≥40.5°C (precaution for future), persistent inconsolable crying ≥3 h (precaution), hypotonic-hyporesponsive episode (precaution), seizure within 3 days (precaution)

— MMR: febrile seizure (peaks 7–10 days post-dose 1; higher with MMRV), thrombocytopenia (1 in 30,000–40,000; transient)

— Rotavirus: intussusception—small absolute risk (~1–5 per 100,000), highest after dose 1; counsel parents on signs (currant jelly stool, episodic crying, abdominal mass)

— HPV/MenACWY/Tdap in adolescents: vasovagal syncope—observe seated 15 min

— Influenza (LAIV): wheezing in <2 y or asthmatics—avoid; use IIV

— Yellow fever: viscerotropic and neurotropic disease, rare; avoid in ≥60 y for first dose

— MenB: local reactions common; no major systemic concerns

— Rate: ~1 per million doses

— Triggers: gelatin (MMR, VAR), yeast (HepB, HPV), neomycin

— Management: IM epinephrine, airway, fluids, antihistamines, steroids

— Future doses: contraindicated for same vaccine; consider allergy referral

— Historical association with 1976 swine flu vaccine; current flu vaccines: rare, ~1 per million

— GBS within 6 weeks of prior tetanus-containing vaccine = precaution for future Tdap

Common, expected reactions (counsel, do not avoid future doses):

Notable specific adverse events:

Anaphylaxis:

Guillain-Barré syndrome:

Board pearl: Reportable Events Table (VAERS): anaphylaxis (0–4 h), encephalopathy (0–72 h for DTaP, 5–15 days MMR), shoulder injury related to vaccine administration (SIRVA), vasovagal syncope (0–1 h), brachial neuritis (Tdap, 2–28 days), intussusception (rotavirus, 1–21 days)—report regardless of causality.

When to Escalate Care and Special Coordination

— Anaphylaxis post-vaccine → IM epi, 911, monitored bed, observe ≥4–6 h; biphasic reaction risk

— Seizure post-vaccine without prior history → ED evaluation, neuro consult if recurrent or focal

— Suspected intussusception post-rotavirus → ED for abdominal US ± air enema reduction

— Allergy/immunology: prior anaphylaxis to vaccine, multiple drug allergies, immunodeficiency workup

— Infectious disease: complex catch-up in HIV, transplant, primary immunodeficiency

— Neurology: evolving neurologic disease (defer pertussis until stable diagnosis)

— Hematology/oncology: vaccine timing around chemotherapy

— Report vaccine-preventable disease cases (measles, mumps, rubella, pertussis, polio, diphtheria, tetanus, HepA, HepB, Hib invasive, meningococcal, varicella in some states) to local health department within 24 h

— Outbreak response: state may authorize accelerated schedules (e.g., MMR at 6–11 months during measles outbreak)

— Provide written immunization record meeting state requirements

— Religious/philosophical/medical exemptions vary by state

— During outbreaks, unvaccinated children may be excluded from school for the duration of the incubation period

— Exposed susceptible patient → post-exposure prophylaxis:

— Measles: MMR within 72 h OR IVIG within 6 days for high-risk

— Varicella: VAR within 3–5 days OR VariZIG within 10 days for high-risk

— HepA: HepA vaccine within 2 weeks; add IG for >40 y or immunocompromised

— HepB: HBIG + HepB vaccine series

— Pertussis: macrolide prophylaxis for close contacts

— Rabies: HRIG + 4-dose vaccine series

Immediate escalation (in-clinic or ED):

Specialist referral:

Public health coordination:

School and daycare entry:

Hospital exposures:

CCS pearl: Suspected vaccine-preventable disease (e.g., measles in unvaccinated child)—order droplet/airborne isolation immediately on triage, notify infection control, public health, and obtain measles IgM + PCR before extensive workup. Don't wait for confirmation to isolate.

Key Differentials — Vaccine Reactions vs Vaccine-Preventable Disease

— Post-MMR: 7–14 days after dose; mild, generalized maculopapular rash; child looks well; no Koplik spots

— Wild measles: 3 Cs (cough, coryza, conjunctivitis) + Koplik spots → cephalocaudal rash; high fever, toxic appearance

— Post-VAR: 1–2 weeks; <10 lesions usually, mild

— Wild: 200–500 lesions in crops, all stages, intense pruritus, fever

— Reaction: <72 h, no fever, no spread beyond site, resolves spontaneously

— Cellulitis: progressive, fever, lymphangitic streaking, requires antibiotics

— Cannot get flu from IIV (inactivated); coincidental URI common

— LAIV may cause mild rhinorrhea

— Vaccine-derived poliovirus: only with OPV (not used in US)

— Vaccine-strain varicella reactivation: can occur years later, milder

— BCG-osis in SCID: live BCG dissemination, fatal if undiagnosed

— Febrile seizure: 6 mo–5 y, fever, generalized, <15 min, returns to baseline, no focal features

— Workup: only if first febrile seizure with atypical features; otherwise reassurance

Post-MMR fever/rash vs measles:

Post-VAR rash vs wild varicella:

DTaP local reaction vs cellulitis:

Post-influenza vaccine illness:

Vaccine-strain disease (rare):

Febrile seizure post-MMRV vs epilepsy:

Key distinction: Anaphylaxis (minutes to 4 h, urticaria + airway/CV/GI symptoms, requires epi) vs vasovagal syncope (immediate post-injection, pallor, bradycardia, recovers with supine positioning, no urticaria). Mislabeling syncope as anaphylaxis incorrectly contraindicates future vaccines.

Board pearl: A child who develops acute encephalopathy within 7 days of DTaP with no other identifiable cause has a contraindication to further pertussis-containing vaccines—use DT (pediatric) instead. This is one of the few absolute pertussis vaccine contraindications.

Key Differentials — Mimics of Vaccine Adverse Events

— Onset of recognition often coincides with 12–18 month MMR timing—coincidence, not causation

— Multiple large studies (Madsen 2002, DeStefano 2013, Jain 2015, Hviid 2019) confirm no link

— Original Wakefield study retracted; license revoked

— Peak 2–4 months overlaps with vaccine schedule

— Large studies show no causal link; some show protective association

— Infant immune system handles thousands of antigens daily

— Combined antigens in modern schedule < antigens in 1980 (whole-cell pertussis alone had 3000 antigens)

— Removed from all routine childhood vaccines in US since 2001 (trace in some multidose flu vials only)

— Ethyl mercury (thimerosal) ≠ methyl mercury; cleared rapidly

— IOM 2004 review: no causal link to neurodevelopmental disorders

Autism spectrum disorder:

SIDS:

Multiple sclerosis and HepB vaccine: No causal association in multiple cohort studies

Diabetes type 1 and vaccines: No causal association

POTS, chronic fatigue, fibromyalgia post-HPV: Reported but no causal association in pharmacovigilance data

"Vaccine overload"/too many too soon:

Thimerosal/mercury:

Aluminum adjuvants: quantities well below toxicity thresholds; oral aluminum from breast milk/formula exceeds vaccine exposure

Genetic mitochondrial disorders presenting post-vaccine (Hannah Poling case): vaccines may unmask but not cause underlying mitochondrial disease; rare

Board pearl: When counseling, acknowledge concerns, share data sources (CDC Vaccine Safety Datalink, Vaccine Adverse Event Reporting System, peer-reviewed studies), and use plain language. Studies show physician strong recommendation is the single most influential factor in parental vaccine acceptance.

Key distinction: Temporal association (event happens after vaccine) ≠ causal association (vaccine caused event). Background rates of childhood illnesses mean some events will always coincidentally follow vaccination.

Long-Term Plan and Lifetime Schedule Integration

— Complete any pediatric series in progress (HPV catch-up through age 26 routine, 27–45 shared decision)

— Tdap → Td or Tdap booster every 10 years lifelong

— Annual influenza

— MenACWY/MenB completion for high-risk

— HepB for all adults 19–59 (universal recommendation as of 2022); ≥60 with risk factors

— Provide updated immunization card

— Schedule next due dates

— Remind about flu vaccine annually starting in September

— Discuss upcoming adolescent vaccines at the 9-year visit (HPV can start at 9)

— Tdap → Td/Tdap every 10 y

— MenACWY: 11–12 y, booster 16 y; high-risk every 5 y lifelong

— MenB high-risk: every 2–3 y

— PPSV23 high-risk: repeat once 5 y after first; one more at 65

— MMR: 2 doses if born ≥1957 and lacking evidence of immunity

— VAR: 2 doses ≥4 weeks apart if non-immune, born ≥1980 in US

— HepB: 3 doses for all 19–59

— HPV: through 26 routine; 27–45 shared decision

— Healthcare workers: HepB, MMR, VAR, Tdap, annual flu, COVID-19

— College students in dormitories: MenACWY (state laws vary)

— MSM, IDU, multiple partners: HepA, HepB, HPV

— Enroll in state IIS at birth; updated at every encounter

— Provide portable record at transitions (moves, college, military)

Transition to adult schedule (≥19 y):

Anticipatory guidance for parents at each well-visit:

Booster intervals to memorize:

Adult catch-up for missed childhood vaccines:

High-risk adult additions:

Documentation continuity:

Step 3 management: At the 18-year visit, complete a "graduation audit": Tdap done? HPV series complete? MenACWY booster at 16? Influenza this season? COVID-19 current? Provide written summary for college/employment health forms.

Follow-Up, Monitoring, and Counseling Touchpoints

— Newborn, 3–5 days, 1 mo, 2 mo, 4 mo, 6 mo, 9 mo, 12 mo, 15 mo, 18 mo, 24 mo, 30 mo, then annually 3–21 y

— Every visit: check vaccine status, address gaps

— Expect soreness, low-grade fever, fussiness 1–2 days

— Acetaminophen 10–15 mg/kg q4–6h or ibuprofen (≥6 mo) 10 mg/kg q6h for discomfort

— Cool compress to injection site

— Return for: temperature ≥40°C, inconsolable crying >3 h, lethargy, seizure, signs of allergic reaction (hives, wheezing, swelling)

— HEDIS Combo 10: 4 DTaP, 3 IPV, 1 MMR, 3 Hib, 3 HepB, 1 VAR, 4 PCV, 1 HepA, 2–3 RV, 2 flu by age 2

— Adolescent immunization: HPV completion, MenACWY, Tdap by 13

— Practice should run immunization registry reports quarterly to identify overdue patients

— Telephone, mail, text, patient portal; evidence-based for improving rates

— School-entry reminders

— At 9 y: introduce HPV ("starting at 9, we'll give a vaccine that prevents cancer")

— At 11 y: Tdap, HPV, MenACWY trio

— At 15 y: MenB shared decision, flu

— Severely preterm <28 weeks first vaccines: monitor 48 h in hospital for apnea

— Prior vasovagal syncope: supine administration, 30-min observation

— Prior local large reaction: still vaccinate; ice and NSAIDs

Well-child visit schedule (AAP Bright Futures) and vaccine integration:

Post-vaccine counseling (give to caregivers at each visit):

Quality metrics tracked:

Reminder-recall systems:

Counseling about future vaccines at each visit:

Special monitoring after specific vaccines:

Board pearl: Standing orders allowing nurses to administer vaccines per protocol (without per-visit physician order) increase coverage rates and are an ACIP/CDC-endorsed quality improvement strategy.

Ethical, Legal, and Patient Safety Considerations

— Provide current VIS for each vaccine each time; document date of VIS edition

— Discuss benefits, risks, alternatives (including risk of disease if unvaccinated)

— Document who gave consent (parent vs legal guardian); foster parents often cannot consent for routine vaccines without state agency authorization—check local law

— Many states allow minors to consent to STI-prevention vaccines (HPV, HepB) without parental involvement; know your state's minor consent statute

— Document confidentiality discussion; bill in a way that preserves confidentiality (avoid EOB disclosure)

— Counsel using CASE/motivational interviewing; address specific concerns

— Document refusal with AAP Refusal to Vaccinate form signed by parent

— Revisit at every visit; never abandon the patient

— Some pediatric practices dismiss families who refuse all vaccines—AAP discourages but does not prohibit; if dismissing, provide adequate notice, records, and referral to avoid abandonment

— Vaccine-preventable diseases (measles, pertussis, etc.) → local health department within 24 h

— Adverse events meeting Reportable Events Table criteria → VAERS

— Suspected medical neglect from severe undervaccination during outbreak → CPS in extreme cases (rare, jurisdiction-dependent)

— Created VICP (no-fault compensation) and VAERS

— Requires VIS distribution and documentation

— Limits manufacturer liability; petitions go to "vaccine court"

— Moving children: provide complete written immunization record + IIS export

— Foster care: state agencies often have central registries; verify before duplicating doses

— Hospital discharge: NICU graduates need clear written plan for catch-up

— VFC program ensures access regardless of insurance

— Address barriers: transportation, work hours, language—use interpreters, evening clinics

Informed consent:

Mature minor and adolescent consent:

Vaccine refusal:

Mandatory reporting:

National Childhood Vaccine Injury Act (1986):

Transition-of-care safety:

Equity:

Step 3 management: When parent refuses HepB birth dose despite mother being HBsAg+, this constitutes a medical emergency for the infant (90% chronic HepB risk without prophylaxis). Engage hospital ethics, social work, and consider court order—document extensively; this is a classic ethics question.

High-Yield Associations and Rapid-Fire Facts

— HepB: birth

— Rotavirus: 6 weeks (max start 14w6d)

— DTaP, Hib, PCV, IPV: 6 weeks

— Influenza: 6 months

— MMR, VAR, HepA: 12 months

— HPV: 9 years (routinely starts 11–12)

— MenACWY: 11 years routine; 2 months if high-risk

— MenB: 16 years routine; 10 years if high-risk

— Live + live: same day or ≥28 days apart

— Inactivated + anything: no spacing needed

— 4-day grace period for most vaccines

"Live" vaccines memorized: MMR, Varicella, MMRV, LAIV, Rotavirus, Yellow fever, BCG, Oral typhoid, Smallpox, Oral polio (not US)

Egg-containing vaccines (no longer a contraindication even in anaphylaxis): influenza (most), yellow fever (still a precaution)

Gelatin in: MMR, VAR, yellow fever, some influenza → anaphylaxis source

Yeast in: HepB, HPV → anaphylaxis source

Neomycin/streptomycin trace: MMR, VAR, IPV

Latex in vial stoppers: rare now; check if severe latex allergy

Minimum ages (memorize):

Spacing rules:

Vaccines requiring 2 doses lifetime in healthy: MMR, VAR, HepA

Vaccines requiring 3 doses: HepB, HPV (if ≥15 y at start)

Vaccines administered IM only: most (HepB, HepA, HPV, DTaP, Tdap, Hib, PCV, IPV in US, MenACWY)

Vaccines administered SC: MMR, VAR, MMRV, MenACWY-D acceptable, IPV acceptable

Vaccines administered orally: rotavirus

Vaccines administered intranasally: LAIV

Board pearl: Hepatitis B vaccine at birth is the single most effective intervention to prevent vertical HepB transmission and chronic infection—universal birth dose since 1991; HBIG + vaccine within 12 h if mother HBsAg+ reduces transmission by >95%.

Catch-up gotcha: Rotavirus has a hard age cutoff (no doses after 8 mo 0 days)—unique among routine vaccines.

Board Question Stem Patterns

— Answer: All routine 2-month vaccines including rotavirus (live, but household immunocompromise is not a contraindication—just hand hygiene)

— Answer: Start full catch-up per US schedule; check HBsAg/anti-HBc, TB screen, HIV in adoptees; do not restart, count valid doses if records emerge

— Answer: No—maximum age for first dose is 14 weeks 6 days; do not initiate

— Answer: 2 doses (0, 6–12 months) because started <15 years and immunocompetent

— Answer: HepB vaccine + HBIG within 12 h, then 4-dose total series (birth, 1, 2–3, 6 mo); test infant at 9–12 mo for HBsAg and anti-HBs

— Answer: Give any age-appropriate flu vaccine in usual medical setting; egg allergy is no longer a contraindication or precaution

— Answer: PPD/IGRA can be falsely suppressed; either do same day as MMR or wait ≥4 weeks

— Answer: Separate MMR + VAR for dose 1 (lower febrile seizure risk); MMRV acceptable for dose 2 at 4–6 y

— Answer: Give all routine vaccines including live; if child develops varicella vaccine rash, cover lesions and minimize contact with father

— Answer: Send maternal HBsAg STAT; if positive or results unavailable within 12 h, give HepB vaccine ± HBIG; engage social work/ethics if refusal continues despite positive result

Stem 1: "2-month-old well-child, mother had GBS, father has lupus on methotrexate. Which vaccines?"

Stem 2: "5-year-old immigrant with no records. Plan?"

Stem 3: "16-week-old has never received rotavirus. Give it?"

Stem 4: "13-year-old getting first HPV dose. How many total?"

Stem 5: "Infant born to HBsAg+ mother, 1800 g. Plan?"

Stem 6: "Child with severe egg allergy needs flu vaccine. What now?"

Stem 7: "MMR given 2 weeks ago, now needs PPD for school. Result?"

Stem 8: "12-month-old presenting for MMR and varicella. MMRV or separate?"

Stem 9: "Father with leukemia on chemo, child needs vaccines. Live vaccines?"

Stem 10: "Mother refusing HepB birth dose, HBsAg unknown. Action?"

Board pearl: Read the age carefully—Step 3 stems hinge on minimum/maximum age and interval rules. Rotavirus age cutoff is the #1 tested catch-up gotcha.

One-Line Recap

Vaccinate at every opportunity using the current CDC/ACIP schedule, never restart a series, distinguish contraindications from precautions, and apply catch-up logic with attention to minimum ages and intervals.

— Live vaccines (MMR, VAR, RV, LAIV, yellow fever, BCG): contraindicated in severe immunocompromise and pregnancy; space same day or ≥28 days; not contraindicated by household immunocompromise or breastfeeding

— Rotavirus has hard age limits: first dose ≤14w6d, final dose ≤8 mo 0 days—never start late

— Adolescent trio at 11–12 y: Tdap + HPV + MenACWY; HPV is 2 doses if started <15 y, 3 doses if ≥15 y or immunocompromised; MenACWY booster at 16

— Not contraindications (don't defer for these): mild illness, low-grade fever, antibiotics, breastfeeding, prematurity, family history of seizures or SIDS, pregnant household member, egg allergy for flu vaccine

— Provide VIS at every dose, document lot/site/route/VIS date per NCVIA, observe ≥15 min post-injection (especially adolescents for vasovagal)

— Universal HepB birth dose; if maternal HBsAg+, add HBIG within 12 h and complete 3-dose (or 4-dose if <2 kg) series

— At every visit—well or sick—review immunization status and offer all due vaccines simultaneously; missed opportunities are quality failures

Top 4 recap bullets:

Top 3 management touchpoints:

Final pearl: Step 3 favors the outpatient longitudinal mindset—use IIS registries, standing orders, presumptive language, and reminder-recall systems; vaccinate the child today, schedule the next dose, and counsel the next milestone.