WEDNESDAY, Dec. 14, 2005 (HealthDay News) -- Giving a pre-transplant vaccine to bone marrow donors could help safeguard bone marrow transplant recipients from deadly pneumonia, say researchers at City of Hope Cancer Center in California.
The vaccine targets cytomegalovirus (CMV), which can cause life-threatening pneumonia in people with seriously weakened immune systems, such as stem cell transplant patients. CMV is present in about half of all people, but is not usually a threat to those with healthy immune systems.
"Our hope is that by giving the [transplant] patient's incoming, new immune system a booster shot before the transplant, they will be better protected," Don J. Diamond, director of the Laboratory of Vaccine Research at City of Hope, said in a prepared statement.
Stem cell transplant patients are at greatest risk of CMV-related pneumonia in the first 40 days following transplant, when their new immune system is taking hold.
"Because CMV is prevalent, most people's immune systems are used to it, and don't need to be very aggressive to keep it at bay. Unfortunately, this also means the immune system won't respond to it very vigorously in its new home after transplant," Diamond said.
The vaccine that his group developed boosts the donor's immune system readiness to respond to CMV. The vaccine contains an altered form of poxvirus that coaxes the donor's body into making large amounts of certain CMV proteins, which activates the donor's immune system prior to transplant.
Laboratory tests with the vaccine indicated that this elevated immunity would be maintained after a transplant and protect the recipient from CMV-related pneumonia. Diamond's team plans clinical trials next year.
More information
The Leukemia and Lymphoma Society has more about blood and marrow stem cell transplantation.
