** Shares of vaccine maker Novavax NVAX.O rise 28.9% to $7.67 premarket

** Co swings to Q1 profit from a year-ago loss, helped by reduced costs related to the development and sale of its COVID-19 vaccines

** Says discussions with the US FDA regarding its proposed study design for its COVID-19 vaccine are ongoing

** Reports Q1 net income came of $519 million, compared to a net loss of $148 million a year earlier

** Reports quarterly revenue of $667 million up from $94 million a year ago, and beating analysts' estimate of $343.85 million, as per data compiled by LSEG

** Last month, the U.S. health regulator asked Novavax to produce more data on its COVID-19 vaccine if it gets full approval

** Up to last close, NVAX down 26% YTD

(Reporting by Sneha S K)

((Sneha.SK@thomsonreuters.com))