london—the biotech startup behind the covid19 vaccine jointly developed by astrazeneca plc and the university of oxford plans as soon as this week to file publicly to sell shares in the us according to people close to the company the oxford startup vaccitech ltd has been aiming for a listed valuation of around 700 million with backers estimating it could be a 1 billion company by yearend the wall street journal reported last month the company recently raised 168 million in new funding in a big step toward a public share offering that financing valued vaccitech at roughly five times its prepandemic value of around 86 million the journal reported citing people close to the company