The Center for Vaccine Development seeks volunteers to take part in a research study of an investigational pneumococcal vaccine. Potential volunteers must be between the ages of 55 and 74, in stable health and have received one pneumococcal vaccine or none at all. Potential volunteers who received one pneumococcal vaccine, must have received it three to seven years prior to enrollment.
Participants cannot get pneumonia from the investigational vaccine. Volunteers will be compensated for time and travel, which includes three to four clinic visits and one scheduled phone visit during approximately six months.
Pneumococcal disease is an illness caused by a type of bacteria called pneumococcus. Pneumococcus can cause pneumonia (infection of the lungs), meningitis (infection of the lining of the brain) and sepsis (infection of blood). Older people run a greater risk of getting the diseases caused by pneumococcus. The best way of protecting against invasive pneumococcal disease is by vaccination. Vaccination causes the body to make antibodies to pneumococcus.
Purpose of study
The purpose of this study is to improve vaccine protection against pneumonia. There are currently two pneumococcal vaccines that have been approved for use in adults 50 years of age and older. One of those vaccines (Pneumovax 23®, Merck & Co., Inc.), called the 23-valent pneumococcal vaccine, has been available for approximately 30 years. This vaccine, which is sometimes called "the pneumonia shot," is designed to prevent infection with 23 of the nearly 100 strains of the pneumococcal bacteria. Pneumovax protects against pneumococcal infection in the blood but not against pneumonia from pneumococcus.
The second vaccine (Prevnar 13®, Wyeth Pharmaceuticals, Inc.), called the 13-valent pneumococcal vaccine, is designed to prevent infection with 13 strains of pneumococcal bacteria; however, it can protect against both pneumococcal infection in the blood and pneumonia. Adults who have been previously vaccinated with Pneumovax 23 and then receive Prevnar 13 tend to have lower antibody levels than adults who have never received Pneumovax 23.
The purpose of this study is to see whether giving two injections of Prevnar 13 to adults who have been previously vaccinated with Pneumovax 23 improves the antibody response to the pneumococcal strains in Prevnar 13. Everyone in this study will receive Prevnar vaccine, either one or two doses.