What is Childhood Immunization Schedule — What to Get and When?

A clear, parent-friendly overview of the routine childhood vaccine schedule, why combination vaccines exist, and how to stay on track.

Why do combination vaccines like MMR exist?

They reduce clinic visits and needle sticks, simplify schedules, and maintain high coverage with no loss of safety or effectiveness.

What if my child misses a dose?

Use a catch-up schedule. You never need to restart a vaccine series—continue from where you left off using age-appropriate intervals.

Are vaccines safe for infants?

Yes. Infant vaccines are rigorously tested for safety and effectiveness; common reactions are mild such as soreness or low fever.

Where can I find my country’s exact schedule?

Check your national health authority (e.g., CDC, ministries of health, WHO regional pages) for brand-specific timing and intervals.

Child & Adolescent Health

Childhood Immunization Schedule — What to Get and When

2025-10-09

Intro

Childhood vaccines protect against serious infections like measles, whooping cough, and polio.
This guide lays out the typical schedule, explains why combination vaccines (like MMR) are used, and shows how to catch up if you fall behind.

Note on regions: Schedules vary by country. Use this as a clear overview, then check your national program for exact timing and brand names.

Key Points

Combination vaccines (e.g., MMR) are used to reduce injections and improve coverage without sacrificing safety or effectiveness.
If you miss a dose, you don’t restart — you catch up with the next age-appropriate dose and interval.
Mild reactions (fever, soreness) are common; serious adverse events are rare.
Keeping routine coverage high prevents outbreaks (e.g., the 2025 measles resurgence).

Background

Routine immunization layers protection across infancy and early childhood, when risks from infections are highest.
Schedules are designed to maximize protection when children are most vulnerable and to minimize visits using combo vaccines tested together.

The Schedule at a Glance (Typical Pattern)

Exact timing varies by country. This table shows common ages and combinations you’ll see in many national schedules.

Age	Vaccines (common abbreviations)	Protects Against	Notes
Birth	HepB #1	Hepatitis B	Given within 24 hours where recommended.
6–8 weeks	DTaP-IPV-HepB-Hib #1 (combo), PCV #1, Rotavirus #1	Diphtheria, tetanus, pertussis; polio; hepatitis B; Hib; pneumococcal; rotavirus	Some programs give MenB #1 here.
4 months	DTaP-IPV-HepB-Hib #2, PCV #2, Rotavirus #2	Same as above	Rotavirus may be 2-dose or 3-dose series depending on brand.
6 months	DTaP-IPV-HepB-Hib #3 (where used), Influenza (seasonal)	Same + flu	Some schedules place the 3rd primary DTaP/Hib/IPV later.
12 months	MMR #1, PCV booster, Hib booster	Measles, mumps, rubella; pneumococcal; Hib	In some regions MMRV (adds varicella) after 12–15 months.
15–18 months	DTaP booster, Varicella #1 (if not MMRV)	Pertussis; chickenpox	Timing varies; some give MMRV here.
4–6 years	MMR #2, DTaP-IPV booster	Measles, mumps, rubella; tetanus, diphtheria, pertussis; polio	School-entry boosters.
11–12 years	Tdap, HPV #1, MenACWY #1	Pertussis booster; HPV-related cancers; meningococcal	HPV: 2 doses if started ≤14; 3 doses if ≥15.
16 years	MenACWY booster; consider MenB series	Meningococcal	MenB timing varies by program and risk.

Why Combination Vaccines Exist

Fewer needles & visits → better adherence.
Simpler logistics → fewer errors, higher coverage.
Tested together → no loss of safety or immune response.

Catch-Up Basics

Never restart a vaccine series due to delay.
Respect minimum intervals between doses (varies by product).
Prior disease (e.g., chickenpox) or documented immunity may change what’s needed.
For accelerated travel needs, clinicians may compress intervals within safety limits.

Risks / Benefits / Prognosis

Benefits: Prevents severe disease, complications, and outbreaks; protects vulnerable infants and immunocompromised people through herd effects.
Risks: Mostly mild and short-lived (fever, soreness). Serious reactions are rare and monitored by pharmacovigilance systems.
Outlook: Maintaining high coverage keeps communities open, kids in school, and hospitals focused on true emergencies.

FAQ

Q: Can I get MMR as three separate shots?
A: Some regions permit separate components, but MMR as a combined vaccine is standard — fewer shots, same safety and protection.

Q: My child had COVID-19. Does that change the routine schedule?
A: COVID vaccination is a separate decision from the routine schedule. Follow your national COVID guidance alongside the routine schedule.

Q: Are aluminum adjuvants safe?
A: Yes. The amounts used are very small and help the immune response. Total exposure is lower than everyday sources like food.

Q: What if my child has an egg allergy?
A: Most routine vaccines are safe; discuss specifics (like some flu vaccines) with your clinician.

Q: Where do I find my country’s exact schedule?
A: Check your national health authority (e.g., ministries of health, CDC/EMA/WHO regional pages).