Biology Reference
In-Depth Information
exposure to young children, particularly in childcare settings, have been proposed
as potential sources of primary HCMV infection in this population. Therefore,
adolescence may also be an important target population for eventual implementa-
tion of HCMV vaccination programs. In recognition of the importance of
the adolescent period in acquisition of primary HCMV infection, the Institute of
Medicine (IOM) modeled its analysis of the potential benefits of a HCMV vaccine
program upon hypothetical administration of vaccine to the adolescent patient
(Stratton et al. 1999).
HCMV Infection and Disease in the Immunocompromised Patient
The potential value of HCMV vaccines is not limited to prevention of congenital
infection. Bone marrow/stem cell transplant and solid organ transplant patients
are at high risk for HCMV disease, pneumonitis, enteritis, retinitis, and viremia.
Although the availability of effective prophylactic and preemptive antiviral
therapy has made HCMV a rare cause of mortality in the HSC transplantation
setting, HCMV-seropositive transplant recipients and seronegative recipients of a
positive graft have a mortality disadvantage when compared with seronegative
recipients with a seronegative donor (Boeckh et al. 2003). HCMV seropositivity
is an important risk factor for impaired graft survival, increased risk of graft-
versus-host disease, and other opportunistic infections such as invasive fungal
infections. Therefore, prevention strategies that employ vaccines capable of stim-
ulating both humoral and cell-mediated immune responses to HCMV may be of
value in further decreasing the incidence and severity of HCMV disease, as well
as these other complications of transplantation. Such vaccines could be adminis-
tered to either the transplant recipient or to the HSC donor prior to transplanta-
tion. Whether the same vaccines that might prove successful in this patient
population would protect against HCMV transmission in women of child-bearing
age is uncertain.
Evidence That Immunity Protects Against HCMV Infection
and Disease
Role of Preconception Maternal Immunity in Protection
Against Congenital HCMV Transmission and HCMV
Disease in the Newborn
Preconceptual maternal immunity to HCMV clearly provides some degree of pro-
tection against the most devastating forms of congenital infection. In a comparison
of outcomes of HCMV-infected infants born to mothers who acquired primary
infection during pregnancy with those of infected infants born to mothers with
