The Drugs Controller General of India on Friday asked the Serum Institute of India to suspend recruitment in its clinical trials of AstraZeneca’s potential coronavirus vaccine in the country until further orders, amid safety concerns, PTI reported.

Pharmaceutical company AstraZeneca on Tuesday had paused late-stage global trials of the vaccine in the wake of a suspected adverse reaction in a participant. The Serum Institute of India is developing the vaccine in collaboration with AstraZeneca and Oxford University.

In an order issued on Friday, VG Somani, the drugs controller general of India, asked for increased safety monitoring of those already vaccinated with the experimental vaccine. Somani asked the Serum institute to submit a plan and report on the same.

Besides this, the drug regulator body also asked the firm to submit clearance from the Data and Safety Monitoring Board in the United Kingdom as well as in India before resuming trials in the future.

The move places further restrictions on the trials, which were already been put on hold by the Serum institute on Thursday, after the DGCI had asked the vaccine maker for details on the suspension of trials overseas. In a show-cause notice to SII, the drug regulator had pulled up the institute for not informing it about AstraZeneca pausing clinical trials of the vaccine candidate in other countries, and for not submitting casualty analysis of the “reported serious adverse events”.

According to the DCGI’s order issued on Friday, the Serum Institute in its reply to the notice said the Data and Safety Monitoring Board noted no safety concerns from the clinical trials of the vaccine conducted in India. However, it added the monitoring board recommended “to pause further enrolment into the study until ongoing investigations of SAE reported in the UK study is completed and the sponsor and the UK DSMB are satisfied that it doesn’t pose any safety concerns”.

“In the view of the above, I Dr VG Somani, Drugs Controller General of India, Central Licensing Authority, after careful examination of your reply and the recommendations of the DSMB in India, in exercise of the powers vested under Rule 30 of the New Drugs and Clinical Trials Rules, 2019, direct to you suspend any new recruitment in the phase 2 and 3 clinical trial till further orders,” the order read. “Increase the safety monitoring of the subjects already vaccinated with the vaccine under trial and submit the plan and report.”

The vaccine, popularly known as the Oxford vaccine, has been widely seen as a leading candidate against the infection. The vaccine, called AZD1222, had produced an immune response against the coronavirus and proved to be safe in early-stage clinical trials, according to results published in medical journal The Lancet.

As many as 17 sites in India are conducting testing for the vaccine. It is being tested on individuals between the ages of 18 and 55. The trials began on August 26.