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Immunization schedule

Last updated: August 23, 2021

Summary

Vaccinations are among the most effective measures of preventive medicine. Especially in infants and young children, they can prevent potentially harmful diseases and hospitalization. Almost no one currently living in the US has seen vaccine-preventable diseases first-hand because their frequency has been dramatically decreased by vaccination. However, they persist worldwide and vaccination programs are essential to prevent future outbreaks of diseases like pertussis, mumps, and measles. In the US, immunization guidelines are published and updated every year by the Centers for Disease Control and Prevention (CDC) and Advisory Committee on Immunization Practices (ACIP). The schedule is designed to protect children when they are most vulnerable and individuals at high-risk before they are exposed to possibly life-threatening diseases.

Furthermore, international travelers are at risk of exposure to vaccine-preventable diseases depending on the region visited and the activities planned. Travelers should therefore seek advice about potential immunizations before departure. At a pretravel consultation, the traveler's prior immunizations, health conditions, and likely exposure to diseases while traveling should be taken into account. Information on travel vaccinations may be found on the CDC and the WHO websites.

Immunization schedule 2019-2020

ACIP immunization schedule

General principles

Different vaccination types can be administered simultaneously (including live attenuated and inactivated vaccines) as specified in the ACIP immunization schedule.
Vaccines are given without dose adjustment for weight.
Missed doses should be caught up by simply continuing with the next doses required in the vaccine series.
Restarting the immunization series (i.e., from the first dose) if one or more doses are missed is never necessary, regardless of how much time has elapsed since the last dose.
The catch-up vaccinations are continued as per the minimum recommended interval between doses

Immunization schedule for birth to 18 months

Overview of immunization schedule for birth to 18 months
	Birth	1 mo	2 mo	4 mo	6 mo	9 mo	12 mo	15 mo	18 mo
Hepatitis B vaccine (HepB)	1^st dose (if infant > 2 kg)	2^nd dose		Catch-up	3^rd dose
Diphtheria and tetanus toxoids, acellular pertussis DTaP < 7 yrs		1^st dose; minimum age 6 weeks Exception: DTaP-inactivated poliovirus 4 years		2^nd dose	3^rd dose	Catch-up		4^th dose
Inactivated poliovirus vaccine (IPV)		1^st dose, minimum age 6 weeks		2^nd dose	3^rd dose
Rotavirus vaccine (RV)		1^st dose orally, minimum age 6 weeks		2^nd dose	3^rd dose
Hemophilus influenza type b vaccine (Hib)			1^st dose, minimum age 6 weeks	2^nd dose	(3^rd dose)	Catch-up	3^rd / 4^th dose (booster dose)		Catch-up
Pneumococcal conjugate (PCV13)			1^st dose; minimum age 6 weeks	2^nd dose	3^rd dose	Catch-up	4^th dose		Catch-up
Meningococcal conjugate			High-risk groups, minimum age of 6 weeks for Hib-MenCY, 2 months for MenACWY-CRM ,and 9 months for MenACWY-D
Hepatitis A vaccine (HepA)							2-dose series at 12–24 months (time between doses: 6–18 months)
Influenza vaccine (IIV)					Annual immunization: 1 or 2 doses
Measles, mumps, rubella vaccine (MMR)					High risk groups prior to international travel: 1^st dose at age 6–11 months		1^st dose (minimum age is 12 months)		Catch-up
Varicella vaccine (VAR)							1^st dose		Catch-up

Immunization schedule for 19 months to 18 years

Overview of immunization schedule for 19 months to 18 years
		19-23 mos	2–3 years	4–6 years	7–10 years	11–12 years	13–15 years	16–18 years
Hepatitis B vaccine (HepB)		Catch-up
Diphtheria and tetanus toxoids, acellular pertussis	DTaP < 7 yrs	Catch-up		5^th dose
Diphtheria and tetanus toxoids, acellular pertussis	Tdap ≥ 7 yrs				Catch-up	Single booster dose of Tdap is recommended If catch-up immunizations with Tdap already administered, the single booster dose is not necessary for adolescents
Inactivated poliovirus vaccine (IPV)		Catch-up		4^th dose	Catch-up
Hemophilus influenza type b vaccine (Hib)		Catch-up			One dose recommended for high-risk groups
Pneumococcal vaccines	Pneumococcal conjugate (PCV13)	Catch-up			Recommended for high-risk groups
Pneumococcal vaccines	Pneumococcal polysaccharide (PPSV23)		High-risk groups, minimum age is 2 years
Influenza vaccine	IIV	Annual immunization: 1 or 2 doses			Annual immunization: 1 dose (> 9 years)
Influenza vaccine	LAIV		Annual immunization: 1 or 2 doses (2–9 years)		Annual immunization: 1 dose (> 9 years)
Hepatitis A vaccine (HepA)		2-dose series at 12–24 months (time between doses: 6–18 months)	Catch-up
Meningococcal conjugate		High-risk groups				1^st dose	Catch-up	Booster dose at age 16 if first dose administered before 16th birthday Catch-up immunization recommended for persons aged 13–18 years
Meningococcal B vaccine (MenB)					High-risk groups: 2 or 3 doses depending on the brand (minimum age: 10 years) Based on clinical discretion: Adolescents and young adults aged 16–23 years to provide short-term protection against most strains of serogroup B meningococcal disease
Measles, mumps, rubella vaccine (MMR)		Catch-up		2^nd dose	Catch-up
Varicella vaccine (VAR)		Catch-up		2^nd dose	Catch-up
Human papillomavirus vaccine (HPV)					High-risk groups, minimum age 9 years	2-dose series (can be ages 9–14 years)	3-dose series for > 15 years	Catch-up

Adult recommendations and duration of protection

Overview immunization schedule for adults
Adult recommendations			Duration of protection
Hepatitis B vaccine (HepB)		For all adults, who want protection from hepatitis B or who are at risk for hepatitis B infection Individuals who do not respond to a primary 3-dose hep B vaccine series (i.e., anti-HBs < 10mIU/mL) should complete a 2^nd3-dose vaccine series Nonresponders: individuals who have an anti-HBs < 10mIU/mL after 6 doses of hep B vaccine, for whom an acute or chronic HBV infection has been ruled out.	At least 20 years
Diphtheria and tetanus toxoids, acellular pertussis		For all adults ≥ 19 years who have never received a Tdap vaccine, provide a dose of Tdap (regardless of the interval since the last tetanus and diphtheria vaccine) Booster doses of Td or Tdap every 10 years All pregnant women should receive a single dose of Tdap at 27–36 weeks of gestation regardless of the interval since the last Tdap or Td vaccination.	Approx. 10 years
Rotavirus vaccine (RV)		Catch-up not routinely recommended for persons ≥ 18 years	Up to 3 years after completion of series
Hemophilus influenza type b vaccine (Hib)		Catch-up immunization for high-risk groups (e.g., adults with asplenia, sick cell disease, or hematopoietic stem cell transplant)	Unknown; requires further investigation
Pneumococcal vaccines	Pneumococcal conjugate (PCV13)	For all adults age ≥ 19 with certain medical conditions (immunosuppression, CSF leaks, chronic renal failure, asplenia, cochlear implants), PCV13 vaccine followed by PPSV23 vaccine at least 8 weeks later is recommended. In immunocompetent adults ≥ 65 years, a shared decision between the physician and patient should be made. In a patient who wishes to receive both, administer PCV13 first and then PPSV23 at least 1 year later.	Not lifelong
Pneumococcal vaccines	Pneumococcal polysaccharide (PPSV23)	Recommended for all adults ≥ 65 years Sequential PCV13 and PPSV23 are recommended for individuals age < 65 with certain high-risk conditions. For adults age < 65 who are current smokers or have a chronic medical condition, PPSV23 vaccine alone is recommended.	Not lifelong
Inactivated poliovirus vaccine (IPV)		Catch-up not routinely recommended for persons ≥ 18 years	Probably lifelong after completion of series
Influenza vaccine (IIV, LAIV)		A yearly vaccine is recommended for all patients every flu season (Oct–April in northern hemisphere; May–Oct in southern hemisphere)	1 season
Hepatitis A vaccine (HepA)		2 doses of HepA vaccine separated by 6–18 months for high risk groups (e.g., travelers to endemic countries, users of recreational drugs, men who have sex with men, patients with chronic liver disease)	At least 25 years in adults and 14–20 years in children
Meningococcal conjugate		Repeat every 5 years in high-risk groups (e.g., patients with asplenia or complement component deficiency, complement inhibitor use, people traveling or residing in high-epidemic countries , microbiologists exposed to Neisseria meningitidis; first-year college students living in residence halls, military recruits)	Up to 5 years
Meningococcal B vaccine		Repeat every 2–3 years in high-risk groups	2–3 years
Measles, mumps, rubella vaccine (MMR)		Catch-up immunization is recommended in high-risk groups	Probably lifelong
Varicella vaccine (VAR)		All adults who have never received the full immunization dose or have not had chickenpox	At least 10–20 years after completion of series
Zoster recombinant vaccine (RZV)		RZV: 2 doses in adults > 50 years (preferred over ZVL)	-
Human papillomavirus vaccine (HPV)		Catch-up immunization recommended for all adults < 26 years 2 doses (0, 6–12 month schedule) in patients who began the immunization schedule at < 15 years 3 doses (0, 1–2 month, 6 month schedule) in patients who began the immunization schedule ≥ 15 years or who are immunocompromised)	No evidence of weakened protection over time after completion of series

“HHating PeDs Immunization/Vaccination MmeHMorizing:” the childhood immunization schedule includes: HepB 0, 2, 6; Hib 2, 4, 6, 12–15; Pneumo: 2, 4, 6, 12–15; DTaP: 2, 4, 6, 15–18, 4–6 years; Td 10 years; IPV: 2, 4, 6, 4–6 years; Varicella 12–15, 4–6 years; MMR: 12–15, 4–6 years; HepA 2 years, Meningococcus 11–12 years.

References:^[1]^[2]^[3]^[4]^[5]^[6]^[7]^[8]^[9]^[10]^[11]^[12]^[13]^[14]^[15]^[16]

Immunizations for travel

Below is only a selection of recommendations. Not included are immunizations recommended for the US. For details on recommendations regarding specific countries, further diseases, vaccinations or drugs, see the CDC Yellow Book.

Overview of travel Immunizations
Immunization	Schedule	Minimum age	Risk areas	Recommendation	Other
Japanese encephalitis vaccine (JE)	2 doses, 28 days apart Should be completed at least one week before exposure Booster if last dose ≥ 1 year ago	2 months	Southeast Asia	Recommended for travelers or US citizens living in endemic areas during periods of JE transmission	There is currently no efficacy data available for the vaccine.
Yellow fever vaccine	1 dose; at least 10 days before departure	9 months	Africa, Central and South America	Recommended for all travelers or US citizens living in risk areas	Many African and South American countries require proof of vaccination from incoming travelers. One dose provides lifelong protection.
Rabies vaccine	3 doses: day 0, 7, and either 21 or 28 (depending on vaccine) Provides protection within ∼ 2 weeks	none	Rabies is endemic on all continents except Antarctica. However, several countries are considered rabies-free.	May be recommended for travelers visiting countries with a high occurrence of animal rabies and low availability of antirabies biologics (e.g., countries in Africa, South America, and Southeast Asia) Depends also on planned activities (e.g., caving, wildlife work in rabies-epizootic areas)	After being bitten by a mammal (e.g., dog, cat, monkey) persons who have been previously vaccinated should get 2 more doses of rabies vaccine (days 0 and 3). Rabies immune globulin is not required.
Typhoid and paratyphoid fever vaccine	Inactivated typhoid vaccine: 1 dose At least 2 weeks before traveling Booster dose every 2 years Live typhoid vaccine: 4 doses; day 0, 3, 5, 7); At least 1 week before traveling Booster dose every 5 years	Inactivated typhoid vaccine: 2 years of age Live typhoid vaccine: 6 years of age	Common in most developing countries, especially in Southern Asia	Recommended for travelers with exposure to potentially contaminated foods and beverages Persons with intimate exposure to a chronic carrier of Salmonella typhi	The vaccine can only prevent illness in about ¾ of cases.
Meningococcal conjugate	Children at 2 months of age: MenACWY-CRM as a 4-dose series at 2, 4, 6, and 12 months of age Children at 7–23 months of age: MenACWY-CRM or MenACWY-D as a 2-dose series Travelers 2–56 years: 1 dose MenACWY-CRM or MenACWY-D Travelers > 56 years: 1 dose of meningococcal polysaccharide vaccine (groups A, C, Y, W combined)	2 months	Sub-Saharan Africa	A quadrivalent meningococcal conjugate vaccination (e.g., MenACWY-CRM or MenACWY-D; protects against serogroups A, C, W, and Y) is recommended for persons traveling or residing in hyperendemic or epidemic countries who are in close contact with natives.	Travelers aged ≥ 2 years going to Saudi Arabia on a pilgrimage to Mecca are required by the Saudi government to provide proof of vaccination with a quadrivalent meningococcal vaccine in the last 3 years. Documentation of 2 doses of a meningococcal vaccine against serogroup A is required for travelers aged 3 months to 2 years.

References:^[17]^[18]^[19]^[20]^[21]^[22]^[23]^[24]^[25]

Pathogens affecting unvaccinated children

Overview of pathogens affecting unvaccinated children
Pathogen	Disease	Clinical features		Treatment
Measles virus	Measles	(High) fever Erythematous maculopapular, blanching, partially confluent exanthem Begins behind the ears along the hairline Disseminates to the rest of the body toward the feet (palm and sole involvement is rare) Brown discoloration and desquamation can appear in severely affected areas. Koplik spots, coryza Generalized lymphadenopathy Malaise Cough Conjunctivitis		Symptomatic treatment Vitamin A supplementation Postexposure prophylaxis (see “Prevention” in “Measles”)
Rubella virus	Rubella	Low-grade fever Fine, nonconfluent, pink maculopapular exanthem Begins on the head, typically behind the ears Extends to the trunk and extremities, sparing palms and soles Postauricular and suboccipital lymphadenopathy Malaise Sore throat, cough Conjunctivitis		Symptomatic treatment
Varicella zoster virus	Chickenpox	Low-grade fever, malaise Simultaneous occurrence of erythematous macules, papules, vesicles, and crusted papules Hypopigmentation of healed lesions can occur. Rash starts on the trunk and spreads to the face, scalp, and extremities. Severe pruritus		Symptomatic treatment Antiviral therapy (first-line: acyclovir, second line: valacyclovir OR famciclovir)
Mumps virus	Mumps	Fever, malaise Inflammation of the salivary glands Most commonly parotitis Usually unilateral Possibly orchitis		Symptomatic treatment
Corynebacterium diphtheriae	Diphtheria	Grayish-white pseudomembranes over posterior pharyngeal wall and/or tonsils Cervical lymphadenopathy and nuchal soft tissue swelling (bull neck) Foul-smelling breath Difficulty breathing, inspiratory stridor		Antibiotic therapy: penicillin G OR erythromycin Diphtheria antitoxin Airway support
Haemophilus influenzae type b	Epiglottitis	High fever Sore throat Dysphagia and odynophagia Drooling Muffled voice (“hot-potato” voice) Respiratory distress		Empiric IV antibiotics Third-generation cephalosporin (e.g., cefotaxime, ceftriaxone) OR beta-lactam with a beta-lactamase inhibitor (e.g., ampicillin/sulbactam, amoxicillin/clavulanate) Adjunctive therapy with steroids (dexamethasone OR methylprednisolone)
Haemophilus influenzae type b	Meningitis	Classic triad: fever, headache, and neck stiffness Photophobia Nausea, vomiting Malaise Altered mental status, seizures	Sore throat, pharyngitis	Empiric antibiotic therapy after obtaining CSF See “Empiric antibiotic therapy for bacterial meningitis.” Tailor antimicrobial therapy once the pathogen is identified. For H. influenzae type b and S. pneumoniae: adjuvant therapy (e.g., dexamethasone) For H. influenzae type b and N. meningitidis: postexposure prophylaxis for close contacts (see “Postexposure chemoprophylaxis for bacterial meningitis”)
Streptococcus pneumoniae			Sinusitis, pharyngitis
Neisseria meningitidis			Myalgia Possibly petechial or purpuric rash Possibly Waterhouse-Friderichsen syndrome
Poliovirus	Meningitis Poliomyelitis		Gastroenteritis Sore throat Myalgia Asymmetric flaccid paralysis Most commonly affects the leg muscles Usually more severe in proximal muscles	Supportive treatment Mechanical ventilation in patients with respiratory failure
Clostridium tetani	Tetanus	Painful muscle spasms and rigidity Trismus, risus sardonicus, opisthotonus Possibly laryngospasm/respiratory muscle spasms, autonomic dysfunction (e.g., circulatory arrest)		Wound cleaning and debridement Antibiotic treatment: metronidazole OR penicillin G Active and passive immunization (see “Tetanus prophylaxis”) Supportive treatment
Bordetella pertussis	Pertussis	Intense paroxysmal coughing (often occurring at night) Followed by a deep and loud inhalation or high-pitched whooping sound Often followed by posttussive vomiting		Supportive treatment Oxygen administration with humidification Antibiotic treatment: macrolides (e.g., azithromycin, clarithromycin, erythromycin)
Hepatitis A virus	Hepatitis A	Right upper quadrant pain, tender hepatomegaly Fever, malaise Anorexia, nausea, vomiting Jaundice, pruritus		Supportive treatment In case of chronic hepatits B: Nucleoside/nucleotide analogs (e.g., tenofovir, entecavir) PEG-IFN-α
Hepatitis B virus	Hepatitis B

References

Child and Adolescent Schedule. https://www.cdc.gov/vaccines/schedules/hcp/imz/child-adolescent.html. Updated: February 3, 2020. Accessed: June 23, 2020.
Epidemiology and Prevention of Vaccine-Preventable Diseases.
Ask the Experts About Rotavirus Vaccines. http://www.immunize.org/askexperts/experts_rota.asp. Updated: July 22, 2016. Accessed: March 23, 2017.
Ask the Experts About Hib Vaccines. http://www.immunize.org/askexperts/experts_hib.asp. Updated: January 29, 2016. Accessed: March 24, 2017.
Briere EC. Food and Drug Administration approval for use of Hiberix as a 3-dose primary Haemophilus influenzae type b (Hib) vaccination series. Morb Mortal Wkly Rep. 2016; 65 (16): p.418-419. doi: 10.15585/mmwr.mm6516a3 . | Open in Read by QxMD
Expanding the potential impact of Haemophilus influenzae type b vaccines (Hib) by optimizing immunization schedules. http://www.who.int/immunization/sage/meetings/2013/april/1_Hib_summary_of_evidence.pdf. Updated: March 26, 2013. Accessed: March 24, 2017.
Hepatitis B FAQs for Health Professionals. https://www.cdc.gov/hepatitis/hbv/hbvfaq.htm#D1. Updated: August 4, 2016. Accessed: March 24, 2017.
HPV Vaccine Information For Young Women. https://www.cdc.gov/std/hpv/stdfact-hpv-vaccine-young-women.htm. Updated: January 3, 2017. Accessed: March 23, 2017.
Meningococcal Vaccination: What Everyone Should Know. https://www.cdc.gov/vaccines/vpd/mening/public/index.html. Updated: December 9, 2016. Accessed: March 24, 2017.
MacNeil JR, Rubin L, Folaranmi T, Ortega-Sanchez IR, Patel M, Martin SW. Use of Serogroup B Meningococcal Vaccines in Adolescents and Young Adults: Recommendations of the Advisory Committee on Immunization Practices, 2015. Morb Mortal Wkly Rep. 2015; 64 (41): p.1171-1176. doi: 10.15585/mmwr.mm6441a3 . | Open in Read by QxMD
MMR vaccine FAQs. http://www.nhs.uk/conditions/vaccinations/pages/mmr-questions-answers.aspx. Updated: October 4, 2015. Accessed: March 24, 2017.
Varicella Vaccine Effectiveness and Duration of Protection. https://www.cdc.gov/vaccines/vpd-vac/varicella/hcp-effective-duration.htm. Updated: August 30, 2012. Accessed: March 24, 2017.
Van Damme P. Long-term Protection After Hepatitis B Vaccine. J Infect Dis. 2016; 214 (1): p.1-3. doi: 10.1093/infdis/jiv750 . | Open in Read by QxMD
Vaccine Non-Responders. http://www.hepb.org/prevention-and-diagnosis/vaccination/vaccine-non-responders/. Updated: January 1, 2018. Accessed: March 29, 2018.
Tomczyk S, Bennett NM, Stoecker C, et al. Use of 13-valent pneumococcal conjugate vaccine and 23-valent pneumococcal polysaccharide vaccine among adults aged ≥65 years: recommendations of the Advisory Committee on Immunization Practices (ACIP). MMWR. 2014; 63 (37): p.822-825.
Viral Hepatitis - Hepatitis A Questions and Answers for Health Professionals. https://www.cdc.gov/hepatitis/hav/havfaq.htm#B4. Updated: October 25, 2017. Accessed: March 29, 2018.
Fischer M, Lindsey N, Staples JE, Hills S. Japanese encephalitis vaccines: recommendations of the Advisory Committee on Immunization Practices (ACIP). Morb Mortal Wkly Rep. 2010; 59 (RR01): p.1-27.
Infectious Diseases Related to Travel - Japanese Encephalitis. https://wwwnc.cdc.gov/travel/yellowbook/2016/infectious-diseases-related-to-travel/japanese-encephalitis. Updated: July 10, 2015. Accessed: March 24, 2017.
Travelers' Health - Yellow Fever. https://wwwnc.cdc.gov/travel/diseases/yellow-fever. Updated: July 10, 2015. Accessed: March 24, 2017.
Clinical Update: Yellow Fever Vaccine Booster Doses. https://wwwnc.cdc.gov/travel/news-announcements/yf-vax-booster. Updated: July 21, 2015. Accessed: March 24, 2017.
Select Destinations - Saudi Arabia: Hajj/Umrah Pilgrimage. https://wwwnc.cdc.gov/travel/yellowbook/2018/select-destinations/saudi-arabia-hajj-umrah-pilgrimage. Updated: June 12, 2017. Accessed: March 29, 2018.
Infectious Diseases Related to Travel - Meningococcal Disease. https://wwwnc.cdc.gov/travel/yellowbook/2018/infectious-diseases-related-to-travel/meningococcal-disease. Updated: June 12, 2017. Accessed: March 29, 2018.
Rabies Vaccine. http://www.who.int/ith/vaccines/rabies/en/. Updated: January 1, 2018. Accessed: March 29, 2018.
Importation - Rabies-Free Countries and Political Units. https://www.cdc.gov/importation/rabies-free-countries.html. Updated: January 23, 2017. Accessed: March 29, 2018.
Infectious Diseases Related to Travel - Typhoid & Paratyphoid Fever. https://wwwnc.cdc.gov/travel/yellowbook/2018/infectious-diseases-related-to-travel/typhoid-paratyphoid-fever. Updated: May 31, 2017. Accessed: March 29, 2018.
Herold G. Internal Medicine. Herold G ; 2014