Provided are a composition, food and drink that exert, through oral ingestion of a lactic acid bacterium, a culture product thereof, a processed product thereof or a composition comprising the same, an effect of enhancing an immune response to an antigen, said antigen being administered via another route such as subcutaneous injection.A composition for oral ingestion for enhancing the proliferation of cytotoxic T lymphocytes (CTL) specific to an antigen and the production of an antibody specific to the antigen, said composition comprising a lactic acid bacterium strain
