Description
LYMErix™ is made from lipidated recombinant outer-surface
protein A (rOspA) of B. burgdorferi sensu stricto. The
rOspA protein is expressed in Escherichia coli and purified.
LYMErix™ contains 30 µg of purified rOspA lipidated
protein absorbed onto aluminum hydroxide adjuvant.
Mechanism
of Action
Evidence from several studies in animals indicates that B.
burgdorferi in a vector tick undergoes substantial antigenic
change between time of tick attachment on a mammalian host and
subsequent transmission of the bacterium to the host. The spirochetes
residing in the tick gut at the initiation of tick feeding express
primarily OspA. As tick feeding begins, the expression of outer-surface
protein C (OspC) is increased and the expression of OspA is decreased,
so that spirochetes that reach the mammalian host after passing
through the tick salivary glands express primarily OspC (66).
The rOspA vaccine appears to exert its principal protective effect
by neutralizing or killing Lyme disease spirochetes within the
tick gut (67).
Route of Administration,
Vaccination Schedule, and Dosage
0.5ml (30 µg) of LYMErix™ is administered by intramuscular
injection into the deltoid muscle. Three doses are required for
optimal protection, with the initial dose followed by a second
dose one month later and a third dose 12 months after the first.
Vaccine administration should be timed so that the second dose
of the vaccine (year one), and the third dose (year two) are
given several weeks before the beginning of the B. burgdorferi
transmission season, which usually begins in April.
