CanSino Biologics Inc., China's adenovirus-based single-dose COVID-19 vaccine producer, saw its first half-year net profit drop by 98.7 percent from a year ago, as global and domestic vaccine demands have been cooling down, according to the company's filing published on Sunday.

The Tianjin-based company also reported a 69.5 percent year-on-year decline in revenue for the same period, attributing the downturn to both weaker vaccine demand and price changes of its products.

The revenue for the January-June period decreased from 2.06 billion yuan ($299.8 million) to 629.8 million yuan, according to the filing.

So far, there are several homegrown mRNA vaccine candidates pushing its vaccine development for the market as an alternative option. CanSino was approved by the National Medical Products Administration of China to conduct clinical trials in April and started in May.