Influenza: More efficient, more protective vaccinations Boosting an influenza vaccine with a different strain offers twice the protection for half the volume of vaccine. Pigs and humans need two doses of killed influenza vaccine—a “priming” dose, with a “booster” given approximately 4 weeks after—in order to provide immunity. Kristien Van Reeth, of Belgium’s Ghent University, and collaborators demonstrated that differing the strain of the primer and booster elicits antibodies that protect against both strains, negating the need for two doses of both strains. The swine vaccinated in Van Reeth’s study also had increased immunity against strains that the animals were not vaccinated against but bore similarities to the viruses used. This cross-protection corresponds with conclusions from similar research into other animals and could eliminate the need for unnecessary vaccinations whilst increasing vaccine efficacy in swine and presumably in humans.
