More Frequent Use of Pneumococcal Vaccine Recommended

ABSTRACT & COMMENTARY

Synopsis: Revaccination is advised if prior vaccine status is unknown or if it has been more than five years since the last vaccination for those at highest risk.

Source: Centers for Disease Control and Prevention. MMWR Morb Mortal Wkly Rep 1997;46 (No. RR-8):1-24.

Since the last national recommendations for pneumococcal vaccine use were issued in 1989, new studies have been published regarding this vaccine’s efficacy, which now enable us to better determine the target populations and the need for additional revaccinations. Pneumococcal infection causes 500,000 pneumonias and 40,000 deaths in the United States annually—more than any other vaccine-preventable bacterial disease. For bacteremic disease, the case fatality rate for the elderly is 30-40%. At least half of these deaths are potentially preventable through pneumococcal vaccination, which has been clearly shown to prevent invasive bacteremic disease but not necessarily other forms of pneumococcal infection.

Recommended candidates for the pneumococcal vaccine now include all persons aged 65 years and older, all persons aged 2-64 years who have functional or anatomic asplenia, who live in long-term care facilities, and who have chronic illness (e.g., CHF, COPD, diabetes, alcoholism, cirrhosis). The vaccine should be given two weeks before elective splenectomy for the greatest effectiveness. Special populations who are at risk for invasive pneumococcal disease, such as Eskimos and certain American Indians, should also be vaccinated. Healthy children and persons with asthma are not included in the recommended vaccination groups at this time.

When this vaccine was first created in 1977 covering 14 capsular polysaccharide antigens, it was not known how long antibody levels would persist and therefore when booster shots might need to be administered. Subsequently, a 23-antigen vaccine was released in 1983, and recommendations were issued that anyone who received the old vaccine should be revaccinated with the new formulation. These 23 antigens represent 85-90% of the serotypes causing invasive infection and include six that most frequently cause drug-resistant pneumococcal infection.

Ongoing studies of antibody levels in healthy adults have now shown that antibody levels persist for at least five years after vaccination but may decline to prevaccination levels in 10 years. This decline appears to be accelerated to 3-5 years in elderly persons, in persons after splenectomy or transplants, and in various other immunocompromised states including dialysis for renal disease and active HIV infection. Although it is unclear if these declining levels mean less clinical immunity, it has prompted the ACIP to recommend that persons at "highest risk" (see Table) be revaccinated after five years. More than two vaccinations in a lifetime are not recommended since data are insufficient on the long-term safety for more doses.

Table

High-Risk Conditions Eligible for Revaccination After Five Years

Asplenia (splenectomy or sickle cell disease)*

HIV infection

Chronic renal failure, Nephrotic syndrome*

Long-term systemic corticosteroid therapy

Generalized malignancy

Leukemia, lymphoma, Hodgkin’s disease, multiple myeloma

Transplantation (organ or bone marrow)*

Any immunosuppressive chemotherapy

* Children age 3-10 years in above categories, consider three-year revaccination

There are no absolute contraindications to the initial vaccination, but if a severe local reaction does occur then revaccination should be avoided. Side effects of the pneumococcal vaccine are generally considered mild, and a recent meta-analysis of nine randomized, controlled trials found fewer than one-third of 7531 patients reporting mild local reactions (e.g., pain at the injection site, redness, or swelling).1 In this analysis, there were no anaphylactic reactions, although they have been rarely reported;2 no deaths or neurologic syndromes (such as Guillain-Barré syndrome) have ever been attributed to the pneumococcal vaccine. For HIV-positive patients, the vaccine may cause a transient rise in viral replication, but its significance is unknown. Both pneumococcal and influenza vaccines can be administered together at separate body sites.

COMMENT BY MARY ELINA FERRIS, MD

This important article reminds us again how critical it is to promote more extensively the use of pneumococcal vaccines (coverage for vulnerable groups in 1993 was only 28%).3 It answers some important questions about whether booster shots should be given, although the guidelines are unfortunately difficult to institutionalize since decisions must be made as to who is a candidate or not. It is possible that future guidelines will include all elderly in a five- or 10-year revaccination scheme, but currently only "high-risk" groups are included. In any case, there should be no hesitation in administering a pneumococcal vaccination to an eligible person whose vaccination status is unknown.

Current data support this vaccine’s effectiveness against invasive bacteremic disease, but research is not so clear against other types of infection such as radiographically diagnosed pneumonia. Technically, the vaccine does not necessarily prevent "pneumonia" but rather prevents "pneumococcal bacteremia." Nonetheless, this is a distinction few patients would probably find important; the important message is that the vaccine will clearly save lives.

Medicare does pay for pneumococcal vaccine, and both hospitals and individual providers may "roster bill" to make group administration easier. The CDC recommends an increased awareness among physicians and more standing orders and other community-based strategies to increase its use. (Dr. Ferris is Associate Clinical Professor, Loma Linda University, and Clinical Associate Professor, University of Southern California.)

References

1. Fine MJ, et al. Efficacy of pneumococcal vaccination in adults: A meta-analysis of randomized controlled trials. Arch Intern Med 1994;154:2666-2677.

2. Centers for Disease Control and Prevention. Recommendations of the Immunization Practices Advisory Committee: Pneumococcal polysaccharide vaccine. MMWR Morb Mortal Wkly Rep 1989;38:64-68, 73-76.

3. Centers for Disease Control and Prevention. Influenza and pneumococcal vaccination coverage levels among persons aged ³ 65 years. MMWR Morb Mortal Wkly Rep 1995;44:506-507, 513-515.