Most vaccinations are given during childhood, but some require boosting during adulthood or are indicated for specific patient populations such as international travelers or those with certain medical conditions. Although generally safe, some vaccines contain live, attenuated organisms that can cause disease in immunocompromised patients. Thus, knowledge of the indications for and contraindications to specific vaccinations is critical to protect adults in special circumstances who are at risk.
Vaccines have helped eliminate or significantly reduce the burden of more than a dozen illnesses.1–3 The Advisory Committee on Immunization Practices (ACIP) of the US Centers for Disease Control and Prevention (CDC) makes recommendations about vaccinations for normal adults and children as well as for certain groups at high risk of vaccine-preventable infections.4Tables 1 and 2 summarize the recommendations for vaccination by medical condition.4 In addition, several applications are available online, including downloadable apps from the (www.cdc.gov/vaccines/schedules/Schedulers/adult-scheduler.html) and the American College of Physicians (http://immunization.acponline.org/app/).
HUMANITY’S GREATEST ADVANCES IN PREVENTING INFECTIOUS DISEASE
Immunization and improved sanitation are humanity’s greatest advances in preventing sickness and death from infectious diseases. Since Jenner’s discovery in 1796 that milkmaids who had contracted cowpox (vaccinia) were immune to smallpox, vaccination has eliminated smallpox, markedly decreased the incidence of many infectious diseases, and, most recently, shown efficacy in preventing cervical cancer (with the human papillomavirus vaccine) and hepatocellular cancer (with the hepatitis B vaccine).1–3
Unfortunately, vaccination rates remain low for most routine vaccinations indicated for adults. For example, about 60% of adults over age 65 receive pneumococcal vaccination, and fewer than 10% of black patients over age 60 receive zoster vaccination.5 Various factors may account for these low rates, including financial disincentives.6
Nevertheless, vaccination remains one of medicine’s most effective defenses against infectious diseases and is especially important in the special populations discussed below. By being steadfast proponents of vaccination, especially for the most vulnerable patients, physicians can help ensure the optimum protection for their patients.
VACCINATING PREGNANT PATIENTS
When considering vaccination during pregnancy, one must consider the risk and benefit of the vaccine and the risk of the disease in both the mother and the child.
In general, if a pregnant woman is at high risk of exposure to a particular infection, the benefits of vaccinating her against it outweigh the risks. Vaccinating the mother can also protect against certain infections in early infancy through transfer of vaccine-induced immunoglobin G (IgG) across the placenta.7 In general, inactivated vaccines are considered safe in pregnancy, while live-attenuated vaccines are contraindicated.4 Special considerations for pregnant women include:
Tetanus, diphtheria, and acellular pertussis (Tdap). One dose of Tdap vaccine should be given during each pregnancy, preferably at 27 to 36 weeks of gestation, regardless of when the patient received a previous dose.8
Inactivated influenza vaccine should be given as early as possible during the influenza season (October to March) to all pregnant women, regardless of trimester.
Inactivated polio vaccine may be considered for pregnant women with known exposure to polio or travel to endemic areas.
Hepatitis A, hepatitis B, pneumococcal polysaccharide, meningococcal conjugate, and meningococcal polysaccharide vaccines can be given to women at risk of these infections. If a pregnant patient requires pneumococcal polysaccharide vaccine, it should be given during the second or third trimester, as the safety of this vaccine during the first trimester has not been established.9
Smallpox, measles-mumps-rubella, and varicella-containing vaccines are contraindicated in pregnancy. Household contacts of a pregnant woman should not receive smallpox vaccine, as it is the only vaccine known to cause harm to the fetus.10
Human papillomavirus vaccination is not recommended during pregnancy.
Yellow fever live-attenuated vaccine. The safety of this vaccine during pregnancy has not been established, and it is in the US Food and Drug Administration (FDA) pregnancy category C. However, this vaccine is required for entry into certain countries, and it may be offered if the patient is truly at risk of contracting yellow fever. Because pregnancy may affect immunologic response, serologic testing is recommended to document an immune response. If the patient’s itinerary puts her at low risk of yellow fever, then writing her a vaccine waiver letter can be considered.11