The race for a Zika vaccine is intense. But it may be missing the most important players

About a year ago, before the Zika virus grabbed global attention, there were zero vaccines for it in development. Today, according to the World Health Organization, there are 30. Some of the work has been astonishingly quick. Human trials for two experimental vaccines have already begun. But a vaccine is likely still several years off, and there are indications the wait could be lengthened by a complication that has little to do with the science of vaccine development: The world’s top-tier pharmaceutical companies are largely hanging back, reluctant to get into the race for a vaccine. Of the vaccines under development, only two projects involve major manufacturers, and in one of those cases — a partnership between GlaxoSmithKline and the National Institute of Allergy and Infectious Diseases — the approach planned is new, untested, and not likely to race to market. The bulk of the work is being done by US and Brazilian government...