Immunotherapy for Infectious Diseases

From: Immunotherapy for Infectious Diseases
Edited by: J. M. Jacobson © Humana Press Inc., Totowa, NJ
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Immunotherapy of Viral Infections Other than HIV
INTRODUCTION
Michelle Onorato and Richard B. Pollard
Our understanding of the immune system’s role in eliminating acute viral infections,
in suppressing latent viral pathogens, and in the pathogenesis of chronic viral infection
has grown in the past decade, leading to strategies for modulating the immune response
as a potential adjunct to existing antiviral therapy when it exists or as stand-alone therapy
in infections for which effective antiviral agents do not yet exist. Administration
of antibody, both to prevent acute infection (as in the case of respiratory syncytial virus
[RSV]) and to ameliorate chronic infection (as in the case of hepatitis B) is but one
example of specifically targeted immunobased therapy. Administration of cytokines,
such as interleukin-12 (IL-12), is a more innovative approach to modulating immune
responses in general and suppressing chronic infection. The adoptive transfer of
pathogen-specific cytotoxic T-cells has been effective in prevention of Epstein-Barr
virus (EBV)-related disease post transplant.
RESPIRATORY SYNCYTIAL VIRUS
RSV is a common pathogen, infecting nearly all children by 6 years of age (1).
Although most infections are mild, the ubiquitous nature of the virus means that the
total number of serious cases is still large. In the United States, RSV is thought to be
responsible for up to 50% of admissions for bronchiolitis and 25% of admissions for
pneumonia among pediatric patients (2). Serious RSV infections tend to occur in
infants younger than 6 months; children with underlying pulmonary or cardiac disease;
and children with chronic or transient immunodeficiency (3–5). However, the most
serious illness and the highest mortality rates are found in posttransplant patients (both
adult and pediatric) and in those undergoing chemotherapy for leukemia; mortality
rates in this population exceed 50% even in those treated with ribavirin (6). Thus, the
morbidity and mortality from RSV infections, together with the lack of an effective
vaccine, have led to the use of respiratory syncytial virus immunoglobulin (RSVIG) for
immunoprophylaxis in high-risk populations. Randomized trials in various pediatric
populations at risk have shown reductions in hospitalizations, hospital days, and intensive
care unit days among the groups receiving the highest dose of RSVIG (7).