The potential of the modified vaccinia Ankara (MVA) vaccine to prevent smallpox in HIV patients will be gauged by the group University Hospitals in Cleveland. Scientists do not know definitively whether the vaccine can offer protection against smallpox as a standalone treatment, like other kinds of smallpox vaccines such as Dryvax. The only FDA approved vaccine for smallpox, Dryvax would likely promote dangerous side effects in HIV patients. However, soreness at the vaccination site was the only side effect reported in German research on the use of MVA among HIV-positive trial participants.