Recombinant proteins produced in insect cells.

Both purified expressed proteins and virus-like particles generated in insect cells by recombinant baculoviruses are being explored as potential vaccines for seasonal and pandemic influenza. Clinical trials have suggested that recombinant hemagglutinin vaccines are well tolerated in healthy and elderly adults, that they induce a functional antibody response, and that they provide protection against seasonal influenza in adults. In one trial, a pandemic formulation of H5 vaccine (rH5) induced neutralizing antibody in adults at rates roughly similar to that seen with egg-derived subvirion H5N1 vaccine. Preliminary data suggest that vaccination with the rH5 can also prime for booster responses on revaccination with drifted strains of H5. Recombinant approaches may be extremely valuable in combating future pandemics and further studies of recombinant pandemic vaccines in humans are needed.