Bengal Chief Minister Mamata Banerjee on Thursday wrote to Prime Minister Narendra Modi seeking his intervention for early approval of Covaxin by the World Health Organisation, without which people having taken the Bharat Biotech jab may face problems travelling abroad.

The chief minister, in her letter, stated that her government has been "receiving both Covishield and Covaxin" from the very beginning.

Even the private sector in the state has procured and administered both the vaccines, she said.

"A large number of students from all over the country travel abroad every year for higher studies and many of them have got themselves vaccinated with Covaxin.

"They came to learn later on that their vaccination certificate is not valid abroad. These students are now in a fix regarding their next course of action and their career is at stake," Mamata wrote to Modi on Thursday.

Many countries are allowing the entry of only those people who have taken WHO-approved vaccines, she noted.

"It is learnt that Covaxin is still not approved by WHO and it is not possible to travel abroad as many countries are allowing only those people who are fully vaccinated with WHO-approved vaccines.

"Hence, I request for your kind intervention so that an early approval is received for Covaxin from WHO so that students do not face any problem. This will also benefit people travelling abroad for job, education, business and any other purposes as well," she added.

Mamata had on Wednesday asked Chief Secretary HK Dwidevi to write to the Union Health Secretary and Cabinet Secretary on this matter.

She had also urged the Centre to take steps to ensure that people inoculated with Covaxin do not face any restriction during their overseas travel.