Greater Benefits of Pneumococcal Vaccines that 'Cover' More Strains

Newswise — The current vaccine against pneumococcal bacteria is effective, but vaccines that "cover" additional strains could further reduce pneumococcal infections in infants and toddlers, according to an Israeli study in the April issue of The Pediatric Infectious DiseaseJournal. The journal is published by Lippincott Williams & Wilkins, a part of Wolters Kluwer Health, a leading provider of information and business intelligence for students, professionals, and institutions in medicine, nursing, allied health, pharmacy and the pharmaceutical industry.

Vaccines covering more strains would be especially effective in preventing infections with antibiotic-resistant pneumococci, according to the study by Dr. Dror S. Shouval and colleagues of Ben-Gurion University of the Negev, Beer-Sheva, Israel.

The researchers analyzed types and causes of pneumococcal infections among children under age three in the Negev region of southern Israel from 2000 to 2004, before the introduction of pneumococcal vaccine. In Israel and other countries, including the United States, children now receive a "7-valent" vaccine (PCV7) that protects against seven of the most common pneumococcal strains.

Infection with pneumococci (Streptococcus pneumonia bacteria) is a serious public health problem, especially in infants and young children. Pneumococcal vaccine is recommended to prevent "invasive" infections such as pneumonia (infection of the lungs) and meningitis (infection of the tissues lining the brain and spinal cord). Less serious but more common infections, including acute conjunctivitis (eye infection) and acute otitis media (middle ear infection), are also caused by pneumococci. Vaccines with Greater Coverage Would Prevent Additional InfectionsThe researchers analyzed nearly 5,500 pneumococcal strains isolated from children with invasive infections, otitis media, or conjunctivitis or from healthy children. The results suggested that PCV7 vaccination would have prevented infections with 37 to 54 percent of strains, depending on the type of isolate.

Vaccines that provided coverage against more pneumococcal strains would afford greater protection. A "10-valent" vaccine (PCV10) designed to cover 10 different strains would have protected the children against 44 to 68 percent of strains. A "13-valent" vaccine (PCV13) covering 13 strains would have prevented infection with 54 to 84 percent of strains identified.

Vaccines with greater coverage would also reduce the risk of infection with strains resistant to penicillin and other common antibiotics. Dr. Shouval and colleagues estimate that upgrading from the PCV7 to the PCV13 vaccine could prevent more than 90 percent of cases of invasive pneumococcal disease and acute otitis media caused by drug-resistant pneumococci—including difficult to treat multidrug-resistant strains.

In the United States, routine vaccination with PCV 7 has led to a dramatic reduction in invasive pneumococcal disease, and some reduction in otitis media caused by pneumococci. As the PCV-10 and PCV-13 vaccines are readied for clinical development, there is a need for more information on how coverage against more strains would affect rates of pneumococcal disease.

The new study—including data on less-serious infections—indicates that the newer vaccines are likely to protect against a broader range of pneumococcal strains. The results suggest significant added benefits of both the PCV10 and PCV13 vaccines. "Moreover, PCV13 has an important potential added benefit over PCV7 and PCV10 in reducing disease by drug-resistant S. pneumonia," the researchers conclude.

About The Pediatric Infectious Disease JournalThe Pediatric Infectious Disease Journal® (http://www.pidj.com) is a peer-reviewed, multidisciplinary journal directed to physicians and other health care professionals who manage infectious diseases of childhood. The journal delivers the latest insights on all aspects of infectious disease in children, from state-of-art diagnostic techniques to the most effective drug therapies and other essential treatment protocols. The Pediatric Infectious Disease Journal is official journal of the Pediatric Infectious Diseases Society and the European Society for Paediatric Infectious Diseases.

About Lippincott Williams & Wilkins Lippincott Williams & Wilkins (LWW) is a leading international publisher for healthcare professionals and students with nearly 300 periodicals and 1,500 books in more than 100 disciplines publishing under the LWW brand, as well as content-based sites and online corporate and customer services. LWW is part of Wolters Kluwer Health, a leading provider of information and business intelligence for students, professionals and institutions in medicine, nursing, allied health, pharmacy and the pharmaceutical industry.

Wolters Kluwer Health is a division of Wolters Kluwer, a leading global information services and publishing company. The company provides products and services for professionals in the health, tax, accounting, corporate, financial services, legal, and regulatory sectors. Wolters Kluwer had 2008 annual revenues of €3.4 billion ($4.9 billion), employs approximately 20,000 people worldwide, and maintains operations in over 35 countries across Europe, North America, Asia Pacific, and Latin America. Wolters Kluwer is headquartered in Amsterdam, the Netherlands. Its shares are quoted on Euronext Amsterdam (WKL) and are included in the AEX and Euronext 100 indices. Visit www.wolterskluwer.com for information about our market positions, customers, brands, and organization.