(Reuters) -American depositary shares of Vaccitech fell nearly 20% in their Nasdaq debut on Friday, giving the co-inventor of the COVID-19 vaccine developed by AstraZeneca Plc and Oxford University a market value of about $464 million.

The biotech firm’s shares opened at $13.62, below the initial public offering (IPO) price of $17 apiece for 6.5 million of its American depositary shares.

The UK-based company was started by two Oxford University scientists and spun out of the university’s Jenner Institute in 2016. Its co-founder Sarah Gilbert was among the scientists who led AstraZeneca’s COVID-19 vaccine development efforts.

Vaccitech said it planned to use the proceeds from the IPO to fund the development of its COVID-19 vaccine technology for treatments targeting prostate cancer, hepatitis B HPV and non-small cell lung cancer.

The company’s vaccine technology uses an altered form of chimpanzee cold virus to transport genetic material that can help boost the human immune system and fight infection.

The biotech startup has already raised $216 million to date from Gilead Sciences, Sequoia Capital China and Oxford Sciences Innovation.

In a securities filing in early April, the company reported a loss of about $17.7 million for 2020 on revenue of $4.8 million.

Its debut comes as mass vaccination programs are underway across the world to fight the pandemic, with a report from U.S. health data company IQVIA Holdings Inc projecting total global spending on COVID-19 vaccines to reach $157 billion by 2025.

(Reporting by Vishwadha Chander in Bengaluru; Editing by Aditya Soni)