Shares of Novavax ($NVAX) spiked on the news that its RSV vaccine met the primary endpoint in a Phase II study. The vaccine works by immunizing women in their childbearing years, causing them to pass on protective antibodies to guard infants. Now it's on to a pivotal trial. "The study was dose confirmatory at 60 micrograms. They will go with an adjuvant and will probably go forward testing two doses administered a month apart, because the greatest response was with using a two-dose regimen," MLV & Co analyst George Zavoico told Reuters. Story