Abstract: The invention concerns a derivative of viral regulatory protein or a fragment of viral regulatory protein or of the alpha interferon or a fragment of alpha interferon, which is carboxymethylated, a method for preparing, use of the resulting product in a method of treatment for the human or animal body, a pharmaceutical composition and a vaccine containing as active principle, at least one of the carboxymethylated proteins or fragments.

Abstract: The serum levels of anti-tat antibodies, tat protein, and p24 protein are predictive of disease progression in HIV infected individuals and serve as prognostic markers. The present invention relates to a method for determining the prognosis of an HIV infected individual by measuring serum levels of one or more of these prognostic markers. In addition, a method for monitoring whether an HIV infected individual is in need of immunization with a tat vaccine and a method for monitoring the efficacy of immunization with a tat vaccine are also disclosed.