Clinical and Laboratory Studies of Live Cytomegalovirus Vaccine Ad-169

Summary Live strain Ad-169 vaccine was prepared in human diploid cell strain WI-38 and studied clinically in 43 adult male priests and seminarians. All seronegative persons who were vaccinated developed antibody, and the immune adherence and neutralizing antibodies persisted at high levels for at least one year. Clinical reactions were minor consisting mainly of soreness, induration, and erythema at the injection site and mild systemic reaction including headache, chills, fatigue, myalgia, and fever in a few persons. It was not possible to recover virus from the peripheral leukocytes, urine, or throat of seronegative persons who were vaccinated. Susceptible persons who were in contact with the vaccinated persons failed both to excrete virus and to develop antibody indicating lack of contagious spread of the vaccine virus. Continuing investigations to measure the safety and efficacy of the vaccine seem highly justified in view of the importance of the virus in fetal damage, transfusion disease, and organ transplantation.