Study to Test Pneumococcal Vaccine in Older Adult
ScienceDaily (Oct. 15, 2012) — Researchers plan to see if a higher dose of a pneumococcal vaccine will create a stronger immune response in older adults who received an earlier generation vaccine against pneumonia and other pneumococcal diseases.
The study supported by the National Institutes of Health will compare two dosages of a pneumococcal vaccine approved for children ages 6 weeks to 5 years, and adults 50 and older. The trial will enroll up to 882 men and women ages 55 to 74
Researchers will conduct a Phase IIb randomized clinical trial, involving two groups of adults ages 55 to 74. The first group, 294 participants who have never been vaccinated with the PPSV23 vaccine, will receive a single 0.5 milliliter (mL) injection of the PCV13 vaccine. The second group, 588 participants who were vaccinated with the PPSV23 vaccine three to seven years before study enrollment, will be randomized to receive one 0.5 mL injection of the PCV13 vaccine or 1.0 mL of the PCV13 vaccine administered as two 0.5 mL injections, one in each arm. Researchers will evaluate participants' immune responses via blood samples drawn 28 days and 180 days post-injection, to compare responses between those who had previously been vaccinated with the PPSV23 vaccine and those who had not been. The researchers will also evaluate whether the larger, 1.0 mL, dose of PCV13 is more immunogenic than the 0.5 mL dose in participants who were previously vaccinated with the PPSV23 vaccine.
Since 92% of pneumonia-related deaths are in those 55 or older, it makes sense that they would be targeted for additional research.