Immunization

Regina C. Larocque

Edward T. Ryan

Immunization represents the most cost-effective means of preventing infectious disease. There are five major categories: (a) routine vaccinations of childhood and adolescence, (b) routine vaccinations of adulthood (Tables 6-1 and 6-2), (c) postexposure prophylactic immunizations, (d) travel-related immunizations, and (e) work-related/special circumstance immunizations. Of these, administration of vaccines during childhood has been most successful; fewer than 100 children die each year of vaccine-preventable illnesses in the United States. In comparison, 50,000 to 70,000 adults die each year in the United States of vaccine-preventable illnesses. Although most people born in the United States receive standard immunizations during childhood, approximately 1 in 10 persons currently living in the United States was born in another country. Many of these people have been incompletely immunized.

GENERAL PRINCIPLES OF IMMUNIZATION (1, 2, 3 and 4)

Overall Efficacy and Safety in Adults

Compared with responses in young adults or children, responses are often lower in elderly or immunocompromised persons; however, vaccines still induce clinically meaningful protective immunity in most adult populations. Vaccine administration in adults is safe. Most adverse reactions from parenteral injections occur at the injection site and include induration, erythema, and tenderness; low-grade fever and mild constitutional symptoms may also occur. Severe complications such as anaphylactic shock occur in less than 1 in 1 million inoculations. Individuals with a high likelihood of having severe reactions can usually be identified before the administration of a specific agent.

Types of Immunization

Immunizations can be either active or passive.

Active Immunization

Active immunization entails the administration of a vaccine (live attenuated microorganisms, killed microorganisms, or purified proteins or polysaccharides of microorganisms) or a toxoid (a deactivated toxin). Active immunization often provides longterm (lasting for years or, less frequently, for life) protective immunity; however, meaningful immunity is often not achieved until 2 to 4 weeks after vaccination. Vaccines that are live attenuated versions of an infectious agent are usually more efficacious and provide longer-lasting immunity than do nonliving vaccines. Similarly, polysaccharide-based vaccines are in general less immunogenic than are protein-based vaccines; however, the coupling of polysaccharide antigens to “carrier” proteins may markedly increase immunologic responses against polysaccharide components.

Passive Immunization

Passive immunization entails the administration of preformed antibody (such as immunoglobulin). Passive immunization results in immediate protective immunity, but such immunity is short term (usually lasting for only 3 to 6 months).

Administration

A host of strategies are available for administration.

Technique

With a few exceptions, most vaccines may be administered simultaneously. An adult can usually tolerate the administration of up to four vaccines (two vaccines administered separately in each deltoid area) in a given appointment. Adults should be vaccinated in the deltoid area of their upper extremities. Because of unreliable absorption, inoculations (other than certain immunoglobulin preparations) should not be administered in the gluteal region. A new syringe and needle should be used for each vaccination/immunization. If more than one live attenuated viral vaccine (e.g., measles-mumps-rubella; varicella or herpes zoster; yellow fever) is indicated, the vaccines should be administered on the same day (at different injection sites) or at least 4 weeks apart. When live vaccines are administered on different days sooner than 4 weeks apart, immunologic responses may decrease.

Combining Passive and Active Immunization

Immunoglobulin preparations (and immunoglobulin-containing blood products) should not be administered with live viral vaccines when the immunoglobulin preparation contains antibodies directed against such viruses. If a patient requires both an immunoglobulin preparation and a live viral vaccine, the live viral vaccine should be administered at least 2 weeks before the immunoglobulin preparation (if possible). If the immunoglobulin preparation is administered first, 3 to 11 months (usually 3 to 6 months) should elapse before the live viral vaccine is administered. The duration of inhibition of a live viral vaccine is related to the dose of immunoglobulin given. (Specific recommendations can be found in Appendix A-19, Epidemiology and Prevention of Vaccine-Preventable Diseases—12th edition, “The Pink Book.”) Simultaneous administration of immunoglobulin preparations and all or any of the nonliving vaccines is not problematic. Persons with immunoglobulin A deficiency should not receive immunoglobulin preparations unless the risk of illness clearly outweighs the risk of anaphylaxis.

Allergic Reactions and Desensitization

A person who has an anaphylactic reaction to eggs or egg proteins should not receive vaccines grown in chick-egg embryos or cell cultures. Gastric or intestinal discomfort after eating eggs is not a contraindication to receiving these vaccines. Vaccines sometimes contain low levels of antibiotics that may trigger an allergic reaction. No vaccine that is available in the United States contains penicillin, so an allergy to penicillin does not contraindicate the use of any vaccine in the United States. However, the measles, mumps, and rubella (MMR); varicella; herpes zoster; and inactivated polio virus vaccines (IPV) do contain low levels of neomycin; individuals with a history of anaphylactic reactions to neomycin should not receive these vaccines. IPV should also not be administered to individuals with a history of anaphylactic reactions to polymyxin B or streptomycin.

If an individual has a history of a reaction to any vaccine, the repeated administration of that vaccine should be carefully weighed against the risk and severity of the illness in that individual and the severity of the previous reaction. For special circumstances, vaccine desensitization protocols are available.

TABLE 6-1 Summary of Recommendations for Routine Adult Immunizations

Vaccine Name and Route	For Whom Recommended	Schedule (Any Vaccine Can Be Given with Another)	Contraindications and Precautions (Mild Illness Not a Contraindication)
Influenza
Inactivated influenza vaccine	▪ All adults	▪ Given every year	Contraindications: ▪ Previous anaphylactic reaction to this vaccine, to any of its components, or to eggs
▪ Give IM		▪ In the temperate Northern Hemisphere, October to November is the optimal time to receive an annual flu shot to maximize protection, but the vaccine may be given at any time during the influenza season (typically December to March) or at other times when the risk of influenza exists	Precautions: ▪ Moderate or severe acute illness ▪ History of Guillain-Barré syndrome within 6 wk of previous administration of influenza vaccine ▪ Pregnancy and breast-feeding are not contraindications to the use of this vaccine
Live attenuated influenza vaccine
▪ Give intranasally	▪ Healthy, nonpregnant adults aged ≤49 y	▪ Same as for inactivated influenza vaccine	▪ Contraindications: ▪ Previous anaphylactic reaction to this vaccine, to any of its components, or to eggs
		▪ If the LAIV and MMR, yellow fever, or varicella vaccines are not given on the same day, then space them at least 28 d apart	▪ Pregnancy, asthma, reactive airway disease, or other chronic disorder of the cardiac or pulmonary systems; an underlying medical condition, including diabetes, renal disease, or hemoglobinopathy; a known or suspected immune deficiency disease or receipt of immunosuppressive therapy; history of influenza-associated Guillain-Barré syndrome ▪ Close contact with severely immunosuppressed persons
Pneumococcal polysaccharide (PPV23)	▪ Adults >65 y of age	▪ Routinely given as one-time dose; administer if previous vaccination history is unknown	▪ Contraindications: ▪ Previous anaphylactic reaction to this vaccine or to any of its components Precautions:
▪ Give IM or SC	▪ Adults ≥19 y of age with chronic heart disease, chronic lung disease, diabetes mellitus, alcoholism, chronic liver disease, cirrhosis, or cigarette use, and persons living in special environments or social settings (residents of nursing homes or long-term care facilities)	▪ Those who received PPSV23 before age 65 y for any indication should receive another dose of the vaccine at age 65 y, or later if at least 5 y have elapsed since their previous PPSV23 dose.	▪ Moderate or severe acute illness
Pneumococcal conjugate (PCV13) (for use in select individuals)	▪ Adults >19 y of age with congenital or acquired immunodeficiency, HIV infection, chronic renal failure, leukemia, lymphoma, Hodgkin disease, generalized malignancy, iatrogenic immunosuppression (as defined by CDC), solid organ transplant, sickle cell disease/other hemoglobinopathy, congenital or acquired asplenia should receive PCV13, to be followed by PPSV23 at least 8 wk later, and revaccinate with PPSV23 booster after 5 y. Adults >19 y of age with cerebrospinal fluid leak or cochlear implant should receive PCV13 once, to be followed at least 8 wk later with PPSV23, with no current recommendation for additional boosters. Of note, PCV13 is not currently recommended for individuals with chronic heart disease, chronic lung disease, diabetes mellitus, alcoholism, chronic liver disease, cirrhosis, or cigarette use. These individuals should receive PPSV23.	▪ Routinely given as one-time dose	Contraindications: ▪ Previous anaphylactic reaction to this vaccine or to any of its components
Hepatitis B (Hep B)	▪ All persons through 18 y; any adult wishing to obtain immunity	▪ Three doses are needed on a 0-, 1-, and 6-mo schedule	Contraindications: ▪ Previous anaphylactic reaction to this vaccine or to any of its components
▪ Give IM	▪ High-risk adults, including household contacts and sex partners of HbsAg-positive persons; users of illicit injectable drugs; sexually active persons not in a long-term, mutually monogamous relationship; men who have sex with men; people with HIV or recently diagnosed STDs; patients in hemodialysis units and patients with renal disease that may result in dialysis; recipients of certain blood products; health care workers and public safety workers who are exposed to blood; clients and staff of institutions for the developmentally disabled; inmates of long-term correctional facilities; certain international travelers ▪ Note: Prior serologic testing may be recommended, depending on the specific level of risk or likelihood of previous exposure.	▪ Alternate timing options for vaccination include 0, 2, and 4 mo and 0, 1, and 4 mo
Brands may be used interchangeably	▪ Persons with chronic liver disease.	▪ There must be 4 wk between doses 1 and 2, and 8 wk between doses 2 and 3; overall, there must be at least 4 mo between doses 1 and 3
	Note: Perform serologic screening for people who have emigrated from endemic areas. When HbsAg-positive persons are identified, offer them appropriate disease management; in addition, screen their household members and intimate contacts and give the first dose of vaccine at the same visit; if found susceptible, complete the vaccine series	▪ Schedule for those who have fallen behind: if the series is delayed between doses, do not start the series over; continue from where it was left off
		Note: Fixed combination of the A and B vaccines should be given on a 0-, 1-, and 6-mo schedule or on an accelerated schedule of 0, 7, and 21-30 d and a booster dose at 12 mo
Hepatitis A (Hep A)	▪ People who travel or work outside the United States, northern and western Europe, New Zealand, Australia, Canada, and Japan	▪ Two doses are needed	Contraindications: ▪ Previous anaphylactic reaction to this vaccine or to any of its components. Precautions:
	▪ People with chronic liver disease, including people with hepatitis C virus infection, people with hepatitis B who have chronic liver disease, illicit drug users, men who have sex with men, people who work with hepatitis A virus in experimental lab settings (this does not refer to routine medical laboratories), and people who anticipate close personal contact with an international adoptee during the first 60 d after arrival from a country with high or intermediate endemicity.	▪ The minimum interval between doses 1 and 2 is 6 mo	▪ Moderate or severe acute illness.
▪ Give IM	▪ Anyone wishing to obtain immunity to hepatitis A	▪ If dose 2 is delayed, do not repeat dose 1; just give dose 2	▪ Safety in pregnancy has not been determined, so benefits must be weighed against potential risks
Brands may be used interchangeably
Td, Tdap (tetanus, diphtheria, pertussis)	▪ All adults who lack a history of a primary series containing at least three doses of tetanus- and diphtheria-containing vaccine	▪ For persons who are unvaccinated or behind, complete the primary series with Td (spaced 0, 1- to 2-, and 6- to 12-mo intervals); substitute a one-time dose of Tdap for one of the doses of Td.	Contraindications: ▪ Previous anaphylactic reaction to this vaccine or to any of its components
	▪ After the primary series has been completed, a booster dose is recommended every 10 y	▪ Give Td booster every 10 y after the primary series has been completed; for adults aged >19 y, a one-time dose of Tdap is recommended to replace one of the Td boosters	▪ For Tdap only, history of encephalopathy within 7 d following DTP/DTaP
	▪ A booster dose of tetanus- and diphtheria-containing toxoid as early as 5 y later may be needed for the purpose of wound management, so consult ACIP recommendations		Precautions: ▪ Moderate or severe acute illness
	For Tdap only:
	▪ All adults who have not received Tdap	▪ Tdap can be administered regardless of interval since the most recent tetanus- or diphtheria-containing vaccine	▪ Guillain-Barré syndrome within 6 wk of receiving tetanus toxoid-containing vaccine
	▪ Health care workers who have direct patient contact and have not received Tdap		▪ History of Arthus reaction after a previous dose of tetanus- and/or diphtheria toxoid-containing vaccine, including MCV4
	▪ Pregnant women	▪ The ACIP now recommends that all women receive a Tdap immunization during each pregnancy. Optimal timing is between 27 and 36 wk gestation to maximize the maternal antibody response and passive antibody transfer to the infant.
	▪ Postpartum women and adults in contact with infants younger than 12 mo who have not received Tdap, including adults aged 65 y and older
Polio (IPV)	▪ Not routinely recommended for persons >18 y of age	▪ Refer to ACIP recommendations regarding unique situations, schedules, and dosing information	Contraindications: ▪ Previous anaphylactic or neurologic reaction to this vaccine or to any of its components
Give IM or SC	Note: Adults living in the United States who never received or completed a primary series of polio vaccine need not be vaccinated unless they intend to travel to areas where exposure to wild-type virus is likely; previously vaccinated adults should receive one booster dose if traveling to polio-endemic areas.		Precautions: ▪ Moderate or severe acute illness.
			▪ Pregnancy Contraindications:
Varicella (chickenpox)	▪ All adults without evidence of immunity	▪ Two doses are needed	▪ Previous anaphylactic reaction to this vaccine or to any of its components
▪ Give SC	Note: Evidence of immunity is defined as a history of two doses of varicella vaccine; born in the United States before 1980 (exception: health care personnel and pregnant women); a history of varicella disease or herpes zoster based on health care provider diagnosis; laboratory evidence of immunity; and/or laboratory confirmation of disease	▪ Dose 2 is given 4-8 wk after dose 1	▪ Pregnancy or possibility of pregnancy within 4 wk
		▪ If the second dose is delayed, do not repeat dose 1; just give dose 2	▪ Persons immunocompromised because of malignancies and primary or acquired cellular immunodeficiency including HIV/AIDS ▪ Note: For those on high-dose immunosuppressive therapy, consult ACIP recommendations regarding delay time
		▪ If the varicella vaccine and MMR, live attenuated influenza vaccine, or yellow fever vaccine are not given on the same day, then space them at least 28 d apart	Precautions: ▪ Moderate or severe acute illness
		▪ If blood, plasma, and/or immune globulin were given in past 11 mo, consult the ACIP guidelines regarding time to wait before vaccinating	▪ Manufacturer recommends that salicylates be avoided for 6 wk after administration of varicella vaccine because of a theoretical risk of Reye syndrome
Herpes zoster (shingles)	▪ All persons aged ≥60 y who do not have contraindications		Contraindications: ▪ Previous anaphylactic reaction to this vaccine or to any of its components
Give SC			▪ Pregnancy or possibility of pregnancy within 4 wk (Manufacturer recommends 3 mo.)
Note: The varicella and the herpes zoster vaccine are not to be used interchangeably; the herpes zoster vaccine contains more than 10 times the amount of live virus as the varicella vaccine			▪ Persons immunocompromised because of malignancies and primary or acquired cellular immunodeficiency, including HIV/AIDS (consult ACIP recommendations regarding definitions of immunocompromising states)
			Precautions: ▪ Moderate or severe acute illness
Meningococcal	▪ A single dose of meningococcal vaccine is recommended for college freshmen living in dormitories; microbiologists routinely exposed to Neisseria menin-gitides; military recruits; and persons who travel to or reside in countries in which meningococcal disease is hyperendemic or epidemic (e.g., the “meningitis belt” of sub-Saharan Africa) during the dry season (December through June).	▪ MCV4 is preferred over MPSV for persons aged ≤55 y, although MPSV is an acceptable alternative	Contraindications: ▪ Previous anaphylactic or neurologic reaction to the vaccine or to any of its components, including diphtheria toxoid (for MCV4)
	▪ Vaccination is required by the government of Saudi Arabia for all travelers to Mecca during the annual Hajj. ▪ A 2-dose series of MCV4 (administered at 0 and 2 mo) is recommended for adults with anatomic or functional asplenia or persistent complement component deficiencies. Adults with HIV who are vaccinated should also receive a 2-dose series.	▪ Revaccination with MCV4 every 5 y is recommended for adults previously vaccinated with MCV4 or MPSV who remain at increased risk for infection.	Precautions: ▪ Moderate or severe acute illness
▪ Give MCV4 IM ▪ Give meningococcal polysaccharide vaccine (MPSV) SC
MMR	▪ Adults born in 1957 or later (especially those born outside the United States) should receive at least one dose of MMR if there is no serologic proof of immunity or documentation of a dose given on or after the first birthday	▪ One or two doses are needed	Contraindications: ▪ Previous anaphylactic reaction to this vaccine or to any of its components
▪ Give SC	▪ Persons in high-risk groups, such as health care personnel, students entering college and other post-high school educational institutions, and international travelers, should receive a total of two doses ▪ Adults born before 1957 are usually considered immune, but proof of immunity (serology or vaccination) may be desirable for health care personnel ▪ Women of childbearing age who do not have acceptable evidence of rubella immunity or vaccination	▪ If dose 2 is recommended, give it no sooner than 4 wk after dose 1 ▪ If MMR and other live viral vaccines are not given on the same day, then space them at least 28 d apart ▪ If a pregnant woman is found to be rubella susceptible, administer MMR postpartum	▪ Pregnancy or possibility of pregnancy within 4 wk ▪ Persons immunocompromised because of cancer, leukemia, lymphoma, or immunosuppressive drug therapy, including high-dose steroids or radiation therapy Note: HIV positivity is not a contraindication to MMR except for those who are severely immunocompromised
			Precautions: ▪ If blood, plasma, and/or immune globulin were given in past 11 mo, see ACIP recommendations regarding time to wait before vaccinating ▪ Moderate or severe acute illness ▪ History of thrombocytopenia or thrombocytopenic purpura Note: If PPD (tuberculosis skin test) and MMR are both needed but not given on the same day, delay PPD for 4-6 wk after MMR
Human papillomavirus (HPV)	▪ All previously unvaccinated girls and women aged 9-26 y. ▪ HPV may be administered to males aged 9-26 y to reduce their likelihood of genital warts.	▪ Three doses are needed on a 0-, 2-, and 6-mo schedule ▪ The minimum interval between doses 1 and 2 is 4 wk and between doses 2 and 3 is 12 wk	Contraindications: ▪ Previous anaphylactic reaction to this vaccine or to any of its components Precautions: ▪ Data on vaccination in pregnancy are limited; vaccination should be delayed until after completion of the pregnancy
Detailed Advisory Committee on Immunization Practices recommendations can be found at http://www.cdc.gov/vaccines/ ACIP, Advisory Committee on Immunization Practices; CSF, cerebrospinal fluid; HbsAg, hepatitis B surface antigen; IM, intramuscular; MCV4, meningococcal conjugate vaccine; MMR, measles, mumps, rubella; MPSV, meningococcal polysaccharide vaccine; PPD, purified protein derivative; PPV23, 23-valent polysaccharide vaccine; SC, subcutaneous; STD, sexually transmitted disease. Adapted from Recommended Adult Immunization Schedule—United States, 2011. Available at http://www.cdc.gov/vaccines/recs/schedules/default.htm

TABLE 6-2 Recommended Adult Immunization Schedule

Vaccine	19-26 y	27-49 y	50-59 y	60-64 y	≥65 y
Influenza	1 dose annually
Tetanus, diphtheria, pertussis (Td/Tdap)	Substitute 1-time dose of Tdap for Td booster; then boost with Td every 10 y				Td booster every 10 y
Varicella	2 doses
Human papillomavirus (HPV)	3 doses (females)
Zoster				1 dose
Measles, mumps, rubella (MMR)	1 or 2 doses		1 dose
Pneumococcal polysaccharide (PPV23)	1 or 2 doses				1 dose
Meningococcal	1 or more doses
Hepatitis A	2 doses
Hepatitis B	3 doses
Open boxes: Recommended for all persons in this age category who lack evidence of immunity. Shaded boxes: Recommended if some other risk factor is present (e.g., on the basis of medical, occupational, lifestyle, or other indications). For detailed recommendations on all vaccines, refer to the text. Adapted from the Centers for Disease Control and Prevention. Recommended adult immunization schedule, by vaccine and age group—United States, 2011.

Vaccination during Pregnancy and Breast-Feeding

Generally, live attenuated viral vaccines should not be administered to pregnant women because of the theoretical risk of transmission of the vaccine virus to the fetus (Table 6-3). A woman who receives a live attenuated viral vaccine should be advised to avoid pregnancy for 1 month following MMR, varicella, herpes zoster, or yellow fever vaccination. Pregnancy in a household contact is not a contraindication to vaccine administration, except to varicella and herpes zoster vaccines if the pregnant woman is not immune to varicella (on theoretical grounds) or (also on theoretical grounds) live influenza vaccine if the pregnant woman did not receive the corresponding inactivated influenza vaccine at least 2 to 4 weeks previously. The yellow fever viral vaccine strain has been transmitted through breast milk, resulting in encephalitis in very young breastfeeding children. The rubella vaccine has been reported to be transmitted through breast milk, but this attenuated virus has not been known to be harmful in the nursing infant. Whether the varicella vaccine is excreted in human breast milk and, if so, whether the infant could be infected are not known. Therefore, varicella vaccine may be considered for a nursing mother. Breastfeeding is a contraindication to receiving the smallpox vaccine.

Vaccination of Immunocompromised Persons

Severely immunocompromised persons should not receive vaccines of live attenuated viruses (Table 6-4). Moreover, an individual with an immunocompromised household contact should not receive the varicella, herpes zoster, or live attenuated influenza vaccine because person-to-person transmission may occur. The MMR vaccine, however, may be administered to individuals infected with the human immunodeficiency virus (HIV) who are not severely immunocompromised. All vaccines of inactivated viruses may be safely administered to immunocompromised individuals, although immune responses may be less than optimal.

Misconceptions about Contraindications

Mild or moderate local reactions to a previous vaccination (including tenderness, redness, or swelling at the injection site or a low-grade fever) are not contraindications to subsequent vaccination. Neither are mild respiratory, intestinal, or flu-like illnesses, low-grade fever, and a history of recent illness contraindications to vaccine administration. Current antibiotic therapy is a contraindication only to the administration of the oral typhoid vaccine (an attenuated bacterial strain that is killed by antibiotics); all other vaccines may be administered to individuals receiving antibiotics. With the exception of allergies to neomycin, streptomycin, or polymyxin B, allergy to antibiotics is not a contraindication to vaccine administration. For individuals in whom a vaccine is otherwise indicated, a history of seizures is not a contraindication to vaccine administration, nor is a history of a non-vaccineassociated chronic demyelinating condition (such as multiple sclerosis or Guillain-Barré syndrome); many such individuals are at increased risk for a number of vaccine-preventable illnesses.

Record Keeping

The National Childhood Vaccine Injury Act of 1986 requires that all health care providers who administer MMR vaccines (in any combination), polio vaccines, or diphtheria, pertussis, and tetanus vaccines (in any combination) maintain immunization records and contact the Centers for Disease Control and Prevention (CDC) and the Food and Drug Administration (FDA) if an adverse reaction occurs (http://www.vaers.hhs.gov). This is true even if a vaccine is administered to an adult. Records should include the date, name of the vaccine, manufacturer, lot number, expiration date, inoculation site, route of administration, and name of the person administering the vaccine. All clinically significant postvaccination reactions should be reported, not just those required by law. Federal law also requires the distribution of vaccine information statements (VIS) to persons (even adults) receiving certain vaccines (MMR, polio, diphtheria, pertussis, and tetanus vaccines in any combination). VIS can be accessed at http://www.cdc.gov/vaccines/pubs/vis/default.htm or http://www.immunize.org/vis (VIS sheets are available in ˜30 languages).

SPECIFIC IMMUNIZATION PROGRAMS (1, 2, 3 and 4)

Tetanus

Despite the fact that almost half of all individuals older than 60 years of age lack protective levels of serum anti-tetanus toxin antibodies, fewer than 100 cases of tetanus occur each year in the United States. Almost all cases of tetanus reported in the United
States occur in adults who did not complete a primary tetanus immunization series or who did not receive appropriate treatment for a tetanus-prone wound. Prevention of tetanus should, therefore, concentrate on primary vaccination and proper postexposure immunization (Table 6-5); immigrants and elderly persons are most likely not to have received a primary immunization series.

TABLE 6-3 Summary of Recommendations on Immunization of Pregnant Women

Vaccine		Should Be Considered If Otherwise Indicated	Contraindicated During Pregnancy	Comment
Routine				Safety during pregnancy has not been determined; the risk associated with vaccination should be weighed against the risk for hepatitis A in pregnant women who may be at high risk for exposure. Immunoglobulin is an alternative.
	Hepatitis A
	Hepatitis B	X		Pregnant women who are identified as being at risk for hepatitis B virus infection during pregnancy should be vaccinated
	Human papillomavirus			Not recommended for use in pregnancy; if a woman is found to be pregnant after initiation of the vaccination series, the remainder of the threedose regimen should be delayed until after completion of the pregnancy
	Influenza (inactivated)	Recommended
	Influenza (live attenuated)*		X
	Measles*		X
	Meningococcal (MCV4)			No data are available on safety during pregnancy
	Mumps*		X
	Pneumococcal (PPV23)			The safety of PPV23 during the first trimester of pregnancy has not been evaluated, although no adverse consequences have been reported among newborns whose mothers were inadvertently vaccinated during pregnancy
	Polio (IPV)			Vaccination of pregnant women should be avoided on theoretical grounds
	Rubella*		X	Rubella-susceptible women who are not vaccinated because they may be pregnant should be counseled about the risk for congenital rubella syndrome and the importance of being vaccinated as soon as they are no longer pregnant
	Tetanus-diphtheria-acellular pertussis (Tdap)	Recommended		ACIP recommends that all women receive a Tdap immunization during each pregnancy. Optimal timing is between 27 and 36 week’s gestation to maximize the maternal antibody response and passive antibody transfer to the infant. If not administered during pregnancy, Tdap should be administered immediately postpartum
	Varicella*		X
	Zoster		X
Travel and Other
	Herpes zoster*		X
	Japanese encephalitis			Pregnant women who must travel to an area where risk of JE is high should be vaccinated when the theoretical risks of immunization are outweighed by the risk of infection to the mother and developing fetus
	Meningococcal (MPSV)	X		Studies of vaccination with MPSV during pregnancy have not documented adverse effects among either pregnant women or newborns
	Rabies	X		Pregnancy is not considered a contraindication to postexposure prophylaxis; if the risk of exposure to rabies is substantial, preexposure prophylaxis might also be indicated during pregnancy
	Typhoid (parenteral and oral*)			No data have been reported on the use of any of the typhoid vaccines among pregnant women
	Yellow fever*			The safety of yellow fever vaccination during pregnancy has not been established, and the vaccine should be administered only if travel to an endemic area is unavoidable and if an increased risk for exposure exists; if international travel requirements are the only reason to vaccinate a pregnant woman rather than an increased risk of infection, efforts should be made to obtain a waiver letter
ACIP, Advisory Committee on Immunization Practices. Asterisk indicates a live attenuated vaccine. Generally, live virus vaccines are contraindicated for pregnant women because of the theoretical risk of transmission of the vaccine virus to the fetus. If a live virus vaccine is inadvertently given to a pregnant woman or if a woman becomes pregnant within 4 wk after vaccination, she should be counseled about the potential effects on the fetus. Vaccination is not ordinarily an indication to terminate the pregnancy. Women should be counseled to avoid pregnancy for 4 wk after vaccination with a live virus vaccine. Adapted from U.S. Department of Health and Human Services, Centers for Disease Control and Prevention. Guidelines for vaccinating pregnant women, 2008. Available at http://www.cdc.gov/vaccines/pubs/preg-guide.htm