Immunizations: Important at every stage of life

By Stephen L. Cochi, M.D., M.P.H.
Captain, United States Public Health Service
Acting Director, National Immunization Program
Centers for Disease Control and Prevention

The National Partnership for Immunization designates every August as National Immunization Awareness Month (NIAM). The goal is to raise awareness about immunization across the lifespan as families prepare for the return to school, and the medical community begins preparations for the upcoming influenza season. This month is a reminder to parents, caregivers, health care providers, and others that immunization improves the quality of life for persons of all ages in the United States.

Immunizations are important at every stage of life. It is just as important for adolescents and adults to get their shots as it is for infants and children. In fact, adolescence and adulthood are opportunities to catch up with vaccinations that may have been missed in childhood.

Immunizations are critical in stopping the spread of diseases that can disable and kill. Health education professionals are in a special position to convey information about these immunizations throughout a person’s life. In this article, some of the key facts about the recommended adult and adolescent vaccines are highlighted to help health care professionals inform patients and others about the vaccines that can best protect them.

Vaccines for Adolescents

The American Academy of Pediatrics recommends specific vaccines for teenagers and college students. These are the varicella (chickenpox) vaccine, the hepatitis B vaccine, the Measles-Mumps-Rubella (MMR) vaccine, the tetanus-diphtheria vaccine, and the meningococcus vaccine for college students.

Varicella (chickenpox) vaccine: Chickenpox is a disease that can have serious complications, especially for older children and adults. It can lead to severe skin infection, scars, pneumonia, brain damage, and death. Also a person who has had chickenpox can get a painful rash called shingles years later. Although many adults had this disease as children and lived to tell the tale, others have not been as lucky. Until we started using the varicella vaccine in the past several years, 100 people died from chickenpox each year and 12,000 had to be hospitalized for it. Now these numbers are greatly reduced.

Chickenpox vaccine can prevent these serious complications and also shingles. Most people who get this vaccine do not get chickenpox. But if someone who got vaccinated does get chickenpox, it is usually a very mild case. They will have fewer spots, are less likely to have a fever, and will recover faster.

If a teenager has not received this vaccination by age 13, he or she should be given two doses of the vaccine with a four to eight week interval between the first and second dose.

Hepatitis B vaccine: This vaccine protects against a serious disease caused by a virus that attacks the liver. This hepatitis B virus (HBV) can cause lifelong infection, cirrhosis (scarring) of the liver, liver cancer, liver failure, and death. Anyone who is 18 years of age or younger should get this vaccine.

Measles-Mumps-Rubella (MMR) vaccine: Everyone should get two doses of the MMR vaccine. The second dose of this vaccine can be given at any age as long as it is at least 28 days after the first dose. Some adults should also get the MMR vaccine. Generally, anyone 18 years of age or older, who was born after 1956, should get at least one dose of the MMR vaccine unless they can show that they have had either the vaccines or the disease.

History has shown us the importance of the second dose of the measles vaccine. The measles vaccine, which was introduced in 1963, led to a 99% reduction in the incidence of measles. However, because many children did not get the vaccine or received only one dose, a measles epidemic struck the U.S. between 1989 and 1991.

A more recent example of how a disease can return involves a teenager who was not vaccinated against the measles. While traveling abroad, he contracted this infectious disease and returned by plane to the United States In the process, he infected two of his fellow students and then his sister after he arrived home.

Measles disease can be serious. Approximately 20% of reported measles cases experience one or more complications. These complications are more common among children younger than 5 and adults older than 20. For every 1,000 children who get measles, one or two will die from it. Measles can also make a pregnant woman have a miscarriage, give birth prematurely, or have a low-birth-weight baby.

Tetanus-diphtheria vaccine: A Tetanus-diphtheria vaccine booster dose is recommended every 10 years after the initial series of shots. Most reported cases of tetanus (lockjaw) occur in people who have never been vaccinated or those who have not had a booster vaccination in the past 10 years.

Meningococcus vaccine: This is required by many colleges for incoming students, particularly those living in college dormitories. Although this disease is highest among children under 1 year of age, it increases in adolescents who are older than 15 years of age, although not nearly to the level that occurs in young children.

Given this information, it is of value to immunize incoming college freshmen with the meningococcal vaccine. However, given that the incidence of the disease begins to rise in late adolescence, it may be more effective to immunize children at 11 to 12 years of age, when they are receiving a series of other vaccines.

A very practical and succinct introduction to meningococcal meningitis for college-bound students, their parents, and others is the brochure, "Meningitis on Campus: Don’t Wait. Vaccinate," produced by the National Meningitis Association. This can be found on the CDC National Immunization Program web site at www.cdc.gov/nip/recs/teen-schedule.htm.

Vaccines for Adults

Many of the recommended vaccines for adults are similar to those recommended for teens. The vaccines recommended for adults are hepatitis B vaccine (for adults at risk), measles-mumps-rubella vaccine (for susceptible adults), tetanus-diphtheria vaccine (for all adults, every 10 years), vaccines for travelers, varicella vaccine (for susceptible adults), the influenza vaccine (for adults 50 and older) and pneumococcal vaccine (for adults 65 and older).

Detailed information on who should get these vaccines and on the diseases they protect against can be found on the CDC web site (www.cdc.gov/nip) and at the National Immunization Partnership web site (www.partnersforimmunization.org/niam.html).

Influenza Vaccine

One vaccine that adults are likely to inquire about this year is the influenza "flu" vaccine. The flu vaccine is the primary method for preventing influenza and its severe complications. There are two types: the "flu shot" which contains an inactivated vaccine (killed virus) and a nasal-spray flu vaccine (sometimes referred to as LAIV for Live Attenuated Influenza Vaccine) which contains attenuated or weakened live viruses. The LAIV is approved only for use for healthy people between the ages of 5 and 49.

The flu virus causes disease among all age groups. Although flu is most common among -children, the rates of serious illness and death are highest among persons 65 years and older and for anyone with medical conditions that place them at increased risk for complications from the flu.

The flu vaccine provides a high degree of protection for the majority of vaccinated children and young adults. One study reported that, for "non-institutionalized" persons who are older than 60, the vaccine was 58% effective in preventing influenza symptoms. It also indicated that this number could be lower for people who are older than 70. In general, the effectiveness of the flu vaccine shot depends primarily on the age and health condition of the vaccinee and how well matched the viruses in the vaccine are with those in circulation during that particular influenza season. Recently, the Advisory Committee on Immunization Practices (ACIP), which advises CDC on vaccine recommendations, recommended that the primary adult groups for the flu vaccine should be:

  • Persons at increased risk for influenza-related complications | For example, adults who are older than 65 years of age, pregnant women, and anyone who suffers from certain chronic medical conditions
  • Persons who are between 50 to 64 years of age | This age group is more likely to have chronic medical conditions
  • Persons who live with or care for persons at high risk | For example, healthcare workers and household contacts who have frequent contact with persons at high risk and who can infect others at high risk for the flu.

The ACIP also recommended the following for the upcoming 2004-2005 flu season:

  • Inactivated vaccine is preferred over live, attenuated influenza vaccine (LAIV) for vaccinating household members, health care workers, and others who have close contact with severely immunosuppressed persons during periods when such persons require care in a protected environment.
  • If a health care worker receives LAIV, the health care worker should refrain from contact with severely immunosuppressed patients for 7 days after vaccine receipt. No preference exists for inactivated vaccine use by health care workers or other persons who have close contact with persons with lesser degrees of immunosuppression.
  • Severely immunosuppressed persons should not administer LAIV. However, other persons at high risk for influenza complications may administer LAIV (see "Personnel Who May Administer LAIV" in the ACIP recommendations1).
  • The 2004-05 trivalent vaccine virus strains are A/Fujian/411/2002 (H3N2)-like, A/ New Caledonia/20/99 (H1N1)-like, and B/Shanghai/361/2002-like antigens. For the A/Fujian/411/2002 (H3N2)-like antigen, manufacturers may use the antigenically equivalent A/Wyoming/3/2003 [H3N2] virus, and for the B/Shanghai/361/ 2002-like antigen, manufacturers may use the antigenically equivalent B/Jilin/20/ 2003 virus or B/Jiangsu/10/2003 virus (see "Influenza Vaccine Composition" in the ACIP recommendations1).

Although influenza vaccination levels increased substantially during the 1990s, further improvements in vaccine coverage levels are needed, chiefly among persons who are older than 65 years and are at increased risk for flu-related complications among all racial and ethnic groups.

There are some actions that the health care community can take to boost influenza rates:

  • Vaccinating before the start of the flu season
  • Vaccinating patients during hospital stays or during routine health care visits so that an extra trip to get a flu vaccination is unnecessary
  • Vaccinating persons who live in closed settings, such as nursing homes and other chronic-care facilities, and the staff who work there
  • Using reminder/recall systems so that high risk populations remember to get their flu shots

Immunizations are among the most successful and most effective public health tools we have for protecting the public against the spread of disease. They have been so successful that smallpox has been eradicated, polio has nearly been eliminated, and many other vaccine-preventable diseases have virtually disappeared.

Despite this success, more can be accomplished. As a result of the success of immunizations, there are clinicians who have never seen certain vaccine-preventable diseases, and there are members of the public who do not perceive them as a threat. The fact that some diseases are rare in the United States does not mean they cannot return; some are just a plane ride away. It is still important for individuals to be protected against vaccine-preventable diseases.

Vaccines not only help to protect individuals, but also help to protect entire communities by preventing and reducing the spread of infectious agents.

The complete ACIP influenza recommendations can be found in the May 28th 2004 edition of CDC’s Monthly Morbidity Weekly Report (MMWR) at www.cdc.gov/mmwr/preview/mmwrhtml/rr5306a1.htm

(Editor’s note: For more information on pandemic influenza, rapid diagnosis, and treatment with antivirals, see Audio conference prepares you for influenza season’ in this issue.)