T-cell responses of vaccinated cancer patients

Following vaccination with defined tumor antigens that are recognized by T cells, a small proportion of cancer patients display tumor regressions. Several reports describe anti-vaccine T-cell responses, evaluated with a variety of methods, for example, by assessing T-cell function or expression of specific TCR. However, a correlation between these T-cell responses and the tumor regressions has not yet been established. It appears that some patients display tumor regression with an unexpectedly low frequency of anti-vaccine T cells.