BEIJING (REUTERS) - CanSino Biologics Inc (CanSinoBIO) said on Wednesday (Feb 24) that it has filed an application in China for approval of its Covid-19 vaccine to become the country's third locally developed shot allowed for use by the general public.

While China has yet to approve rival vaccines developed by Western drug makers, it has granted authorisation to domestic products that have also gained ground in many developing countries battling a surge in coronavirus infections.

CanSinoBIO said interim analysis of data from its multi-country trial showed that its candidate, known as Ad5-nCoV, has an efficacy rate of 65.28 per cent at preventing all symptomatic cases and 90.07 per cent at preventing severe disease 28 days after a single dose has been given.

But the one-dose vaccine showed its protection rate declined slightly over time; it had a success rate of 68.83 per cent at preventing all symptomatic disease and 95.47 per cent at preventing severe disease 14 days after the vaccination.

"The efficacy of Ad5-nCoV has met the relevant technical standards laid out by the World Health Organisation and relevant standards and requirements set out... by the National Medical Products Association," the company said in a statement, adding it filed the application on Sunday.

The vaccine has already been approved in Pakistan and Mexico and is set to become the third locally developed Covid-19 vaccine in China, should it get approval for use by the general public.

China approved vaccines from Sinovac Biotech and an affiliate of state-backed China National Pharmaceutical Group (Sinopharm).

These vaccines can be stored at normal freezer temperatures, making them a potentially attractive option to many developing countries, which struggle to use rival products such as vaccines from Pfizer and Moderna, which require much colder temperatures for longer-term storage.

China has export deals with 22 countries and is providing vaccine assistance to 53 developing countries, according to its foreign ministry, as it aims to cultivate goodwill with lower-income countries.

CanSinoBIO's vaccine is jointly developed with China's military research unit and was approved for use in the country's military last year.