Addressing Immunization Barriers, Benefits, and Risks

C L I N I C A L

R E V I E W

THE JOURNAL OF

FAMILY PRACTICE

Addressing Immunization Barriers, Benefits, and Risks SANFORD R. KIMMEL, MD; ILENE T. BURNS, MD, MPH;

AND

RICHARD K. ZIMMERMAN, MD, MPH

Toledo, Ohio, and Pittsburgh, Pennsylvania

Immunization rates in the United States still fall short of the Healthy People 2010 goals for children and adults. To improve rates of immunization, physicians need to understand and address barriers to immunization, including fragmented health-care delivery, missed opportunities to vaccinate, and the patient’s fear of adverse reactions. This article addresses these issues and suggests strategies by which rates can be improved, such as patient reminders, standing orders, and assessment of and feedback on practitioner performance. Additionally, it provides suggestions to help physicians better communicate vaccine risks and benefits to their patients, potentially affecting an individual’s acceptance of those risks. It describes the appropriate use of materials such as the Vaccine Information Statements. Physicians should also be prepared to answer patients’ questions about alleged or controversial vaccine adverse events. ■ KEY WORDS

Vaccine; vaccination; immunization

R A T E S O F VA C C I N A T I O N Children

Thousands of children each year develop vaccinepreventable diseases, and thousands more are at risk because of inadequate immunization, despite the benefits of immunizations. Recent rates of vaccination in children show both declines and increases: during 2000, the proportion of children in the United States between 19 and 35 months of age who received four doses of diphtheria and tetanus toxoids and pertussis vaccine (DTaP), three doses of polio vaccine, three doses of Haemophilus influenzae type b vaccine (Hib), and one dose of measles-containing vaccine declined from 78% to 76% compared with 1999.1 On a more positive note, 90% of children in this age group received all three doses of hepatitis B vaccine. Those who received varicella vaccine increased from 59% to 68%.1 The Healthy People 2010 target for vaccine coverage among young children is 90% for all universally recommended vaccines.2

From the Department of Family Medicine, Medical College of Ohio (SRK), the Department of Family Medicine, University of Pittsburgh School of Medicine (ITB and RKZ), and the Department of Behavioral and Community Health Services, Graduate School of Public Health (RKZ). Address correspondence to Sanford R. Kimmel, M.D., Department of Family Medicine, Medical College of Ohio, 1015 Garden Lake Parkway, Toledo, Ohio 43614, Phone: 419383-5525, Fax: 419-382-7876, E-mail: [email protected].

KEY POINTS FOR CLINICIANS

• Reminding patients about immunizations, providing feedback on practitioner performance, and giving standing orders to vaccinate can all raise immunization rates. • Informing patients and/or their parents about vaccine benefits and risks can raise compliance. • Providing the current Vaccine Information Statement each time a vaccine is required by the National Childhood Vaccine Injury Act.

Adults

Adults are inadequately immunized against influenza and pneumococcus. They may also be inadequately protected against tetanus, rubella, varicella, or hepatitis A or B. In 1999, 67% of adults 65 and older received influenza vaccine, and 55% reported a history of pneumococcal vaccination.3 Disparities in immunization rates exist for minorities and high-risk patients. In 1996, 67% of white Medicare enrollees reported receiving influenza vaccination compared with 46% of African Americans.4 Among adults with non-gestational diabetes, 52% reported influenza vaccination in 1997, and 33% reported a history of pneumococcal vaccination.5

The Journal of Family Practice

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| A D D R E S S I N G I M M U N I Z AT I O N B A R R I E R S , B E N E F I T S , A N D R I S K S |

Although the benefits of immunizations are often obvious to health-care providers, patients, parents, and the general public may have questions or concerns about vaccinations. As knowledge of the devastation caused by many vaccinepreventable diseases fades from public memory, attention shifts to the occasionally serious adverse events that may follow immunization. The dissemination of (mis)information and anecdotal reports of alleged vaccine reactions via the media, Internet, and anti-vaccine groups causes parents, patients, and even some health-care providers to question the justification for immunizations. Consequently, vaccines have become victims of their own success.

BARRIERS TO IMMUNIZATION Immunization providers and recipients may encounter logistical or perceptual barriers to achieving higher immunization rates. Logistical barriers include fragmented health care, vaccine costs and availability, scheduling complexity, expanding target populations for vaccination, missed opportunities to immunize, and missed attendance for well-person visits. Perceptual barriers include lack of awareness of immunization rates in the provider’s practice and region, misconceptions about the prevalence or severity of vaccine-preventable diseases, and concerns about safety and efficacy of vaccines. Fragmentation of care

In our mobile society, many children do not spend their entire childhood under the care of a single “medical home.” Continuity of care for children who do not experience geographical relocations may be interrupted by changes in insurance carriers and in arrangements between providers and insurers. Health-care professionals may have difficulty determining which immunizations are needed for new patients who have not maintained personal copies of their immunization records. The development and expansion of vaccine registries may minimize the effect of lost records and patient mobility and help to minimize missed opportunities for vaccination. Va c c i n e c o s t s a n d a v a i l a b i l i t y

Uninsured and underinsured persons without full coverage for immunization costs are at a higher risk for inadequate immunization. The federal Vaccines for Children (VFC) program provides states with free vaccines for children who are Medicaid-eligible, have no health insurance, or are Native Americans or Alaskan natives. In addition, children whose insurance does not cover vaccines are eligible for VFC if they are vaccinated at a fed-

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erally qualified health center or rural health clinic. Further information about the VFC program is available from the Centers for Disease Control and Prevention (CDC) at www.cdc.gov/nip/vfc. Shortages of tetanus-containing vaccines, measles-mumps-and-rubella vaccine (MMR), varicella vaccine, and pneumococcal conjugate vaccine (PCV7) may have delayed immunizations and require patient recall when vaccines become available. Recall systems may be simple “tickler files” of index cards containing the person’s name, address, and required vaccine(s) or even a sophisticated computerized recall system. Because of delays in manufacture and distribution of influenza vaccine, high-risk individuals and health-care workers have first priority for immunization beginning in October.6 Children under 9 years of age who are receiving their initial dose of influenza vaccine should also be immunized in October.6 Information about prioritizing early influenza vaccination is available at www.cdc.gov/nip/ flu/Provider.htm. Expanding schedule and indications

Vaccines new to the pediatric schedule and expanded indications for vaccination in some adult populations have increased the number of immunizations recommended. For example, influenza vaccine is now recommended routinely for those 50 and older.6 The number of office visits required to complete immunization is also potentially increased. Combination vaccines minimize the number of injections needed at a given visit but present additional options for choosing vaccines to stock and schedules to follow. Depending on the age of initiation and manufacturer, various preparations of the same vaccine (e.g., Hib, hepatitis A and B) can have different schedules, doses, and different numbers of doses in a complete course. Missed opportunities and missed attendance at office visits

A missed opportunity for immunization occurs when a candidate for vaccination visits a healthcare provider, but no immunization is given. Whenever possible, immunization status should be addressed, even during visits for acute problems. Illnesses such as an upper respiratory infection with low-grade fever are usually not contraindications to immunization. Patients who do not visit a physician may be unaware of the need for immunization. Among Medicare beneficiaries interviewed in 1996, 57% of responders cited not knowing that pneumococcal vaccine was needed as the reason they were unvaccinated.7 Lack of clinician awareness of immunization rates

Busy clinicians may be unaware of the rates of immunization within their own practices. Relying

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on a casual review of patient immunization records within a single practice may lead to overestimation of immunization rates. A systematic audit of adult and pediatric charts is required to identify possible low rates among patients who do not present routinely for health maintenance. This type of assessment and feedback has been demonstrated to increase adult immunization rates.8 Reviewing patient risk factors during chart audit may also prompt realization that additional vaccines are indicated. The Clinic Assessment Software Application (CASA) can perform immunization rate audits and generate reminder and recall notices. It can be downloaded free of charge at www.cdc.gov/nip/casa.

PUBLIC PERCEPTION O F VA C C I N E S A F E T Y Because immunizations are usually given to healthy people to prevent a serious disease, the risks of the known adverse reactions to the vaccine must be weighed against the potential benefits. The indication for the vaccine is much clearer when the disease incidence is high. It becomes less obvious as vaccine use increases and disease incidence falls. If a loss of confidence in a vaccine develops, an outbreak of disease may ensue, resulting in resumption of vaccine use. This pattern is illustrated in Figure 1.9 Physicians must accurately portray the benefits of immunization while acknowledging that vac-

cines are not always effective and may (rarely) be accompanied by serious adverse events. The known risks of vaccination must be communicated to vaccine recipients or their legal guardians. In one national survey, over 80% of respondents indicated that they received immunization information from a doctor.10 Physicians should inform patients that vaccines are biologic agents intended to stimulate immunity; as such, they commonly cause local reactions such as redness, swelling, and soreness at the injection site. Severe adverse effects such as high fever, seizures, or even encephalopathy have rarely followed some immunizations. A Canadian study found that most mothers would accept a 1:100,000 to 1:1,000,000 risk of a severe vaccine side effect; however, 14% would not tolerate any serious risk.11 Common misconceptions

Most parents support immunizing their children, but misconceptions exist. Some patients believe that too many immunizations weaken the immune system10 or cause chronic diseases such as asthma, autism,12 diabetes, or multiple sclerosis. Parents who are non-vaccinators may believe they can control their child’s susceptibility to disease, have doubts about the reliability of vaccine information, prefer errors of omission over errors of commission, or rely on herd immunity to protect their child.13 Table 1 summarizes factors affecting vaccine risk perception.14 Multiple vaccines and the immune system. Almost one-quarter FIGURE 1 of parents believed that “children get STEPS CORRELATING VACCINATION PROGRAM WITH VACCINE SAFETY CONCERNS. more immunizations than are good for them.”10 Offit and colleagues reported that, although more vaccines are now given, the actual number of antigens Disease in these vaccines has decreased.15 For example, the wholecell pertussis vaccine had approximately 3,000 antigens compared to 2 to 5 for acellular pertussis vaccine.15 The smallpox vaccine has about 200 proteins, exceeding the combined 123 to 126 proteins and polysaccharides From: Chen RT, Hibbs B. Vaccine safety: current and future challenges. Pediatric Annals 1998;27:446. present in DTaP, IPV, MMR, Hib, vari-


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VISs before the visit or while the patient is waiting may facilitate the FACTORS AFFECTING VACCINE RISK PERCEPTION discussion. Addressing parent concerns. Factor Comment Parents who refuse immunization for their children may have personal, Voluntary controllable risks More acceptable than involuntary risks cultural, religious, or experiential Natural risks More acceptable than man-made risks reasons for their beliefs. The physiFrightening or memorable risks Less acceptable than less frightening or cian should acknowledge the parmemorable risks ents’ concerns and correct any misCompression Overestimate frequency of rare risks and information they may have received. underestimate frequency of common risks In some cases it may be helpful to Risks due to commission (action) bias Less acceptable than those due to omission, ask parents to adopt the child’s posii.e., not vaccinating tion and weigh the risks of death Ambiguity aversion Known risks may be more acceptable than and morbidity from disease versus unknown risks of lesser magnitude, e.g., possible risks from the vaccine.14 risks of disease vs. new vaccine These parents may be asked to compare how they would feel if an Freeloading Rely on high vaccination rate and herd adverse outcome resulted from immunity to protect unvaccinated either taking an action or its omisBandwagoning Vaccinate because everyone else is sion. Parents who refuse immunizaAltruism Accept personal risk to benefit community or tion because they believe that immusociety nization of other children protects Information abstracted from the text of Ball LK, Evans G, Bostrom A. Pediatrics 1998;101;453–58. their child (freeloading) should know that this action increases risk for disease in their child and in vaccinated children.14 A Colorado study 15 cella, PCV7, and hepatitis B vaccines. Instead of demonstrated that vaccine exemptors were more weakening the immune system, vaccines may prethan 22 times more likely to acquire measles and vent infections that predispose individuals to serialmost 6 times more likely to develop pertussis ous diseases such as varicella complicated by than vaccinated children.18 necrotizing group A β-hemolytic streptococcal fasciitis in children or pneumonia in adults.15 TABLE 1

Common vaccine risks

E X P L A I N I N G VA C C I N E BENEFITS AND RISKS Physicians or other providers must provide the current Vaccine Information Statement (VIS) each time they administer a vaccine that is covered under the National Vaccine Injury Compensation Program (VICP) or is purchased through a CDC grant.16 They must record the date of administration, the vaccine manufacturer, the lot number, and the name and business address of the provider, along with the edition of the VIS and the date the vaccination was provided in the patient’s medical record.16 Copies of each VIS can be obtained from the CDC at www.cdc.gov/nip/publications/vis or from the Immunization Action Coalition at www.immunize.org. Vaccine recipients or their guardians should also be asked if they have any questions about the vaccines, including the reason for the vaccine’s administration. Answers to “Six Common Misconceptions about Vaccination and How to Respond to Them” can be obtained from www.cdc.gov/nip/ publications/6mishome.htm. Because physicians and nurses cite time as the most common barrier to communicating with patients about vaccine risks and benefits,17 providing the appropriate

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Pain, swelling, and redness at the injection site are common local reactions following immunization. Sterile abscesses occasionally occur after injection of inactivated vaccines, possibly because of irritation from a vaccine component or inadvertent subcutaneous injection of an intramuscular vaccine.16 Fever and irritability are common systemic reactions that may be attenuated by giving acetaminophen at the time of immunization or immediately afterward. Increased fever, redness, swelling, and pain at the injection site have been reported following the fourth dose as compared to the first dose of the licensed diphtheria-tetanus-acellular pertussis (DTaP) vaccines.19 Swelling of the entire thigh or upper arm lasting a mean of 4 days has occurred in 2% to 3% of children following their fourth or fifth dose of the same consecutive DTaP.19 All licensed DTaP vaccines were less likely to elicit common reactions than diphtheria-tetanuswhole-cell pertussis (DTwP) vaccines.20 Local reactions to vaccines or their components are not usually considered contraindications for vaccine administration. Uncommon vaccine risks

Allergic reactions occur infrequently after immunizations. For example, the rate of anaphylaxis

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after hepatitis B vaccine is 1 in 600,000.16 Yeast proteins may cause this reaction.21 Neomycin, an antibiotic, and gelatin, a vaccine stabilizer, are both used in the production of the MMR and varicella vaccines. However, persons with a history of food allergy to gelatin rarely develop anaphylaxis after

vaccine administration.16 MMR vaccine—but not influenza vaccine—may be given to persons with egg allergy.16 Seizures and/or hypotonic-hyporesponsive episodes were both previously reported to occur after 1 of every 1,750 DTwP immunizations and

TABLE 2 MEASLES, MUMPS, AND RUBELLA DISEASE AND VACCINE FACT SHEET Measles, mumps, rubella vaccine

Risks and sequelae

Measles disease

Mumps disease

Rubella disease

Risk of acquiring disease Highest number US cases

894,134 cases in 194125

152,209 cases in 196826

Recent number US cases Highest number US cases congenital rubella Recent number US cases congenital rubella

86 cases in 200028

338 cases in 200028

12 million cases in 1964–196527 57,686 cases in 196927 176 cases in 200028 20,000 cases in 1964–196527

Transmission route

Droplet spray

Transmission to susceptible household contacts

90%25

9 cases in 200028

None reported after immunization of pregnant women but the theoretical risk is 2%29

Direct contact, airborne droplets and fomites Rate not available because 30%–40% infections are subclinical26

Oral droplets or transplacentally 50–60% of susceptible family members and almost 100% in closed populations27

2.5–50 deaths/million mumps cases due to 1.4–2% fatality if develop encephalitis26,31

1 death/30,000 rubella cases due to 20% fatality if develop encephalitis27

Risk of sequelae Case fatality rate

Encephalitis Subacute sclerosing panencephalitis Pneumonia

1–3 deaths per 1000 measles cases16,25

1–2 cases/1000 measles 1/400–1/6000 cases31 cases25 8.5 cases/million measles cases25

1/5000–1/6000 cases27,29

1 death not attributed to vaccine.30 Fatal measles pneumonitis in one young man with advanced HIV29 1 case/million doses30

20 reported cases of

0 to 0.7 cases/million

progressive rubella panencephalitis27

doses25 2 cases/million doses30

1%–6% of persons with measles32

Thrombocytopenia

Rare31

Orchitis

14%–35% adolescent and adult men26,30

1/3000 rubella cases27

0.5–33 cases/million doses16,30 0.3 cases/million doses30

Anaphylaxis

5 cases/million doses; none fatal30

Vaccine efficacy

95% with single dose at 12–15 mos of age. Second dose, ages 4–6 yrs, improves efficacy16

Copyright 2002, Society of Teachers of Family Medicine. Used with permission.


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acute encephalopathy in 0 to 10.5 cases per 1 million doses of DTwP vaccine.22 In 1991, the Institute of Medicine concluded that DTwP vaccine did not cause infantile spasms, Reye syndrome, or sudden infant death syndrome (SIDS).23 Febrile seizures, persistent crying lasting 3 hours or more, and hypotonic-hyporesponsive episodes also have been reported very rarely after DTaP, which is now the vaccine recommended for use in the United States.22 Inactivated poliovirus vaccine (IPV) is the recommended vaccine in the United States for the prevention of acute poliomyelitis. Oral polio vaccine (OVP) with its risk of vaccine-associated paralytic poliomyelitis (1 case per 2.4 million doses of OPV) is no longer justified for routine use because wild poliovirus has been eradicated from the Western hemisphere and many other parts of the world.24 Tables 2 and 3 compare the risks of wild measles, mumps, rubella, and varicella disease with adverse events reported after the MMR and varicella vaccines. Adverse events that are temporally

related to administration of a vaccine do not prove causation. Vaccine efficacy indicates the effectiveness of the vaccine in preventing the disease. Controversial and unproven vaccine risks

Chronic diseases are often attributed to vaccines because immunizations are given at a time in children’s lives when the signs and symptoms of those diseases first become apparent. Parents are understandably frustrated. In their search for answers, they may allege that vaccines caused the illness because of the temporal relationship between immunization and disease appearance. Well-controlled studies have yet to document causation. The alleged link of measles, mumps, and rubella vaccine (MMR) vaccine to autism was highlighted by Wakefield’s study of 12 children with gastrointestinal diseases and developmental regression.38 The report did not include viral studies and stated, “We did not prove an association between measles, mumps, and rubella vaccine and the syndrome described.”38(p.641) Taylor

TABLE 3 VARICELLA DISEASE AND VACCINE FACT SHEET Risks and sequelae Risk of acquiring disease

Varicella disease

Varicella vaccine

Average number US cases/yr Transmission route

3.7 million/yr (1980–1990)33 Direct contact or airborne spread respiratory tract secretions; transplacental passage 90% in susceptible household contacts33;