Governments want Covid vaccine developers to aim higher in hunt for better shots

As governments prepare to live with Covid-19, some are questioning how much to rely on drugmakers to adapt vaccines to ward off future virus variants amid signs of tension between companies and regulators over the best approach, according to several sources familiar with the matter.

Some vaccine experts say government agencies should fund and help develop a new generation of Covid shots, and seek innovation from smaller developers, as they did to identify current vaccines...