Recommendations of the Immunization Practices Advisory Committee (ACIP) Update: Pneumococcal Polysaccharide Vaccine Usage -- United States
These revised recommendations of the Immunization Practices Advisory Committee (ACIP) on pneumococcal polysaccharide vaccine update the previous recommendations (MMWR 1981;30:410-2, 417-9) to include current information and practices.
A 23-valent polysaccharide vaccine against disease caused by Streptococcus pneumoniae (pneumococcus) was licensed in the United States in 1983. It replaces the 14-valent polysaccharide vaccine licensed in 1977. This statement includes new data that have become available about pneumococcal vaccine and its effectiveness and new recommendations regarding its use for selected persons and groups.
Pneumococcal disease is important, because it is responsible for a substantial number of cases and deaths in the United States each year. Although pneumococcal pneumonia accounts for less than 25% of all pneumonia, it is, nevertheless, a common disease. Pneumococcal pneumonia occurs in all age groups. In adults, its incidence increases gradually among those over 40 years old, with a twofold increase in incidence among those over 60 years old. Estimates on the occurrence of serious pneumococcal diseases in the United States are based on surveys, research reports, and several community-based studies (Table 1).
Mortality from pneumococcal disease is highest among patients with bacteremia or meningitis, patients with underlying medical conditions, and older persons. In some high-risk patients, mortality has been reported as high as 40% for bacteremic disease and 55% for meningitis. These rates occur despite therapy with antibiotics, such as penicillin, to which most (97%) clinically significant pneumococci isolated in the United States are exquisitely sensitive.
Patients with certain chronic conditions are clearly at increased risk of developing pneumococcal infection, as well as experiencing more severe pneumococcal illness. These conditions include: sickle cell anemia, Hodgkin's disease, multiple myeloma, cirrhosis, alcoholism, nephrotic syndrome, renal failure, chronic pulmonary disease, splenic dysfunction, and history of splenectomy or organ transplant. Other patients may be at greater risk of developing pneumococcal infection or having more severe illness because of diabetes mellitus, congestive heart failure, or conditions associated with immunosuppression. Patients with cerebrospinal fluid (CSF) leakage complicating skull fractures or neurosurgical procedures can have recurrent pneumococcal meningitis.
PNEUMOCOCCAL POLYSACCHARIDE VACCINES
The new pneumococcal vaccine is composed of purified, capsular polysaccharide antigens of 23 types of S. pneumoniae (Danish types 1, 2, 3, 4, 5, 6B, 7F, 8, 9N, 9V, 10A, 11A, 12F, 14, 15B, 17F, 18C, 19A, 19F, 20, 22F, 23F, and 33F). Each polysaccharide is extracted separately and combined into the final product. Each dose of the new vaccine contains 25 ug of each polysaccharide antigen.
The 23 bacterial types represented in the current vaccine are responsible for 87% of bacteremic pneumococcal disease in the United States reported to CDC in 1983, compared with 71% for the previous 14- valent formulation (1). Studies of the cross-reactivity of human antibodies against related types suggest that cross-protection may occur among some of these types (e.g., 6A and 6B) (2).
Although the new polysaccharide vaccine contains only 25 ug of each antigen, compared with 50 ug of antigen in the old 14-valent vaccine, a study of 53 adults reveals comparable levels of immunogenicity of the two vaccines (3). Most healthy adults show a twofold or greater rise in type-specific antibody, as measured by radioimmunoassay, within 2-3 weeks after vaccination. In contrast, the vaccine is generally less antigenic for children under 2 years old than for other vaccinees. However, because the precise protective titers of antibody for any of these serotypes have not been established, measuring antibody levels in vaccinated persons is not indicated.
EFFECTIVENESS OF PNEUMOCOCCAL POLYSACCHARIDE VACCINES
In the 1970s, two randomized, controlled trials were conducted in populations with a high incidence of disease in South Africa and New Guinea using newly formulated pneumococcal vaccine (4,5). Both studies demonstrated significant reductions in the occurrence of pneumonia in these young, healthy populations.
It should be noted, however, that two randomized, controlled trials of pneumococcal vaccine in older-aged U.S. adults showed less satisfactory results (6). One was of outpatients over 45 years old; the other, of inpatients of a chronic-care psychiatric facility. In neither study was there any difference in the occurrence of respiratory morbidity and mortality between those vaccinated with a polyvalent pneumococcal vaccine and those given a placebo. In the first study, data suggested some vaccine protection against bacteremic pneumococcal disease, but the incidence of pneumococcal disease was low and may not have enabled a valid assessment of vaccine efficacy. In the other study, there were no fewer cases of radiologically diagnosed pneumonia among vaccinees than among controls.
Another method for estimating the efficacy of pneumococcal vaccine compares the distribution of serotypes of pneumococci isolated from the blood of vaccinated and unvaccinated persons (9). Recent data obtained by this method are based on comparing 210 S. pneumoniae isolates from the blood of persons who received the 14-valent vaccine with 1,475 blood isolates from unvaccinated persons. These data show that among persons over 60 years old with no underlying illness or no chronic pulmonary disease, chronic heart disease, or diabetes mellitus, the estimated efficacy ranges between 60% and 80%. However, among persons with cirrhosis or renal failure, the estimated efficacy appears to be lower.
In another recent study, controls were matched to 90 patients with systemic evidence of pneumococcal infection (isolates from blood, CSF, or other normally sterile body fluids) (10). Although vaccine efficacy was 0% for patients with severe immunocompromising conditions, it was 70% for all patients over 55 years of age and 77% for patients at moderately increased risk of pneumococcal infection.
Only a few studies of pneumococcal vaccine efficacy in children have been conducted. In a small, nonrandomized study of children and young adults 2-25 years old who had sickle cell anemia or had had splenectomy, the occurrence of bacteremic pneumococcal disease was significantly reduced by immunization with an 8-valent vaccine (7). Pneumococcal vaccine has shown no significant benefit in preventing otitis media in children (8).
The duration of protection induced by vaccination is unknown. While elevation of antibody titers has been shown 5 years after immunization, studies of persistence of elevated titers are ongoing.
RECOMMENDATIONS FOR VACCINE USE
Newly available data regarding vaccine efficacy support the broader use of pneumococcal vaccine in the United States. Vaccination is particularly recommended for the following:
When elective splenectomy is being considered, pneumococcal vaccine should be given at least 2 weeks before the operation, if possible. Similarly, when immunosuppressive therapy is being planned, as in patients who are candidates for organ transplants, the interval between vaccination and initiation of immunosuppressive therapy should be as long as possible.
Although vaccine failures have been reported in some of these groups, especially those who are immunocompromised, vaccination is still recommended for such persons because they are at high risk of developing severe disease.
STRATEGIES FOR VACCINE DELIVERY
Programs for vaccine delivery to these high-risk groups need to be developed further to achieve maximum immunization rates in such groups. More effective programs are needed for giving vaccine in nursing homes and other chronic-care facilities, in physicians' offices, and in hospitals, as only a small proportion of severe pneumococcal disease occurs in previously healthy individuals.
Two-thirds of persons with serious pneumococcal disease have been hospitalized within 5 years before the pneumococcal illness (11). Vaccine can be given to hospitalized patients -- including at time of discharge -- to prevent future admissions for pneumococcal disease. In addition, persons who visit physicians frequently and have chronic conditions are likely to be at higher risk of pneumococcal infection than those who require infrequent visits. Office-based programs to identify and immunize the frequent user of medical care should help prevent pneumococcal illness. Furthermore, pneumococcal vaccine and influenza vaccine can be given at different sites at the same time without an increase in side effects (12).
Medicare has partially reimbursed the cost of pneumococcal vaccination since 1981. It has been determined that hospitals may be reimbursed for pneumococcal immunization of Medicare recipients independent of reimbursement based on systems of prospective payments.
About half of those given pneumococcal vaccine develop mild side effects, such as erythema and pain at the injection site. In less than 1% of those given pneumococcal vaccine, fever, myalgias, and severe local reactions have been reported (6,13,14). Severe adverse effects, such as anaphylactoid reactions, have rarely been reported -- about 5 per million doses administered. For additional information, the package insert should be reviewed.
It should be emphasized that pneumococcal vaccine should be given only once to adults. Arthus reactions and systemic reactions have been common among adults given second doses (15) and are thought to result from localized antigen-antibody reactions involving antibody induced by previous vaccination. Therefore, second or "booster" doses are not recommended, at least at this time. Data on revaccination of children are not yet sufficient to provide a basis for comment.
Persons who have received the 14-valent pneumococcal vaccine should not be revaccinated with the 23-valent vaccine, as the modest increase in coverage does not warrant the possible increased risk of adverse reactions. However, when there is doubt or no information on whether a person has ever received pneumococcal vaccine, the vaccine should be given. Complete records of vaccination can help to avoid repeat doses.
The safety of pneumococcal vaccine for pregnant women has not been evaluated. It should not be given to otherwise healthy pregnant women. Women at high risk of pneumococcal disease ideally should be vaccinated before pregnancy.
Disclaimer All MMWR HTML documents published before January 1993 are electronic conversions from ASCII text into HTML. This conversion may have resulted in character translation or format errors in the HTML version. Users should not rely on this HTML document, but are referred to the original MMWR paper copy for the official text, figures, and tables. An original paper copy of this issue can be obtained from the Superintendent of Documents, U.S. Government Printing Office (GPO), Washington, DC 20402-9371; telephone: (202) 512-1800. Contact GPO for current prices.**Questions or messages regarding errors in formatting should be addressed to firstname.lastname@example.org.
Page converted: 08/05/98
This page last reviewed 5/2/01