Immunostimulatory microsphere

A macroporous microsphere comprising a particle and an antigenic component, selected from the group consisting of whole inactivated pathogens and submits thereof, RDNA derived polyreptides, recombinant viruses, synthesized polypeptides and anti-idiotypes, and whole microorganisms or animal cells wherein said antigenic component is physically entrapped in or chemically crosslinked, to the interior of said particle, said particle being comprised of a polymer, and said microsphere having size of 1 to 1000 .mu.m, and pores with a mean pore diameter of 0.1 to 100 .mu.m.