image: Superinfection: infection with a strain of CMV triggers an immune response, including the activation and expansion of cytotoxic CD8+ T cells. The virus persists mainly in the latent form. A secondary infection by the same or similar CMV occurs if the secondary virus blocks MHC class I antigen presentation to the virus-specific CD8+ T cells. This image relates to an article that appeared in the April 2, 2010, issue of Science, published by AAAS. The Perspective paper, by Dr. Hartmut Hengel of Heinrich-Heine-University in Düsseldorf, Germany, and Dr. Ulrich H. Koszinowski of Ludwig-Maximilians-University in Munich, Germany, was titled, "A Vaccine Monkey Wrench?" view more
Credit: N. Greenman/<i>Science</i>