FDA approves pneumococcal vaccine in older adults

The FDA has approved the use of the 13-valent pneumococcal conjugate vaccine for the prevention of pneumococcal disease in adults aged 50 years and older, according to an FDA press release. The approval supports the Department of Health and Human Services’ “Healthy People 2020” objectives.

After the FDA’s recommended use of the vaccine (Prevnar 13, Wyeth Pharmaceuticals) in the older age group, the agency granted accelerated approval of the vaccine on the condition that a clinical trial is conducted during the post-approval marketing for the verification of the anticipated clinical benefit, according to the release.

The approval was based upon various randomized, multicenter studies conducted in the United States and Europe that included adults aged 50 years and older. Participants were assigned either Prevnar 13 or to the already licensed pneumococcal vaccine approved for use in this age group (Pneumovax 23, Merck).

Prevnar 13 induced antibody levels either comparable to or higher than Pneumovax 23. An additional trial aiming to confirm the clinical benefit of Prevnar 13 is under way in a cohort of 85,000 adults aged 65 years and older.

“According to recent information for the United States, it is estimated that approximately 300,000 adults 50 years of age and older are hospitalized yearly because of pneumococcal pneumonia,,” Karen Midthun, MD, director of the FDA’s Center for Biologics Evaluation and Research, said in the release. “Pneumococcal disease is a substantial cause of illness and death. [The] approval provides an additional vaccine for preventing pneumococcal pneumonia and invasive disease in this age group.”

Of all bacteria, pneumococci produce the most potentially preventable morbidity and mortality in adults. With an estimated 4 million pneumococcal illnesses in the United States each year, the availability of a new vaccine is most welcome. This new 13-valent conjugate vaccine already is being used universally in the routine infant and childhood immunization schedule. It’s predecessor, the seven-valent vaccine was dramatically successful in the near-elimination of invasive disease (bacteremia, meningitis, etc.) caused by the seven pneumococcal vaccine serotypes in the children. Less well-appreciated were the indirect effects of the vaccine. Because the seven-valent also curtailed pneumococcal carriage in the children’s nasopharynx, it also interrupted the transmission of those seven serotypes. Children, it turns out, are the major transmitters of pneumococci to adults and when those serotypes were eliminated from children, they no longer were transmitted to adults. Thus, disease caused by those serotypes also was reduced dramatically in adults. Careful surveillance is in place to determine whether the new 13-valent vaccine will have a similar effect.

For years physicians already have been providing at-risk adults protection against invasive pneumococcal disease by using the 23-valent polysaccharide vaccine according to the recommendations of the ACIP. The ACIP now is considering recommendations that relate to both of the pneumococcal vaccines now available. Should there be a preference? If so, for which? Are there advantages/disadvantages to using both? If so, could they be given concurrently or, if in sequence, in what order and at what interval? Ought persons already vaccinated with polysaccharide vaccine also receive the conjugate vaccine — and why? Those are but some of the questions with which the members of the ACIP are wrestling.

Here are some questions for the rest of us: Can we keep the two vaccines straight in our medical records systems? Heck, can we keep them straight in our office refrigerators? Given the vagueness of most immunization histories in our adult patients, perhaps these two pneumococcal vaccines will convince us and our public health department partners that adult practioners need the same sort of effective and comprehensive vaccine registries already found so useful by our pediatrician and family practice colleagues.

– William Schaffner, MD

Infectious Disease News Editorial Board member

President, National Foundation for Infectious Diseases

Disclosure: Dr. Schaffner reports no relevant financial disclosures.

Approval and the eventual availability of Prevnar 13 raises myriad of questions regarding optimal use of the vaccine; unfortunately, virtually none of these questions can be answered at the present time. Examples: Should the 13-valent conjugate vaccine be used preferentially in the elderly? Should it be used preferentially only in high-risk elderly? What will be the future role of the existing 23-valent polysaccharide vaccine? Will the additional 10 capsular-types present in the 23-valent vaccine matter? How much pneumococcal infection in the elderly is caused by those additional 10 capsular-types? Does antibody raised by the conjugate vaccine differ in any significant way from antibody produced by the polysaccharide vaccine? Do both vaccines have a role to play and if so, should they be administered sequentially or simultaneously? What if the clinical trial in progress shows no clinical advantage of the conjugate vaccine? Will it be covered by Medicare?

I am personally delighted that the 13-valent conjugate vaccine is now available, but there is clearly much yet to be learned. It will be most interesting to see how the ACIP will deal with this product.

– Theodore C. Eickhoff, MD

Editor Emeritus of Infectious Disease News

Disclosure: Dr. Eickhoff reports no relevant financial disclosures.

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