(Bloomberg) -- Novavax Inc. sold 1.5 million more of its Covid-19 shots to the US, bringing total orders of the vaccine from the government to about 4.7 million.  

The delivery is part of a modification to its existing agreement with the US, Gaithersburg, Maryland-based Novavax said Monday in a statement. The deal will also help the vaccine maker develop smaller dose vials and update its protein-based vaccines with newer Covid strains. 

Novavax and other Covid vaccine makers are preparing to sell their shots directly to US health providers instead of the government, which has been its main customer in the country. The company received some $1.6 billion in US subsidies to develop and make its shot.

Shares of Novavax rose 2.2% before US markets opened. 

The drugmaker’s protein-based vaccine technology is more traditional than the messenger RNA-based products made by Pfizer Inc. and Moderna Inc. It was hoped to appeal to the vaccine-hesitant, but has seen relatively little use compared with the mRNA shots that were authorized earlier.

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