March 12 (UPI) -- Several more countries have suspended distribution of AstraZeneca's COVID-19 vaccine over concerns about blood clotting that's been seen in a few isolated cases.
Thailand is the first Asian nation to suspend the vaccine, which was developed by AstraZeneca and Britain's Oxford University.
The recipients who experienced blood clotting issues had received vaccines from a batch produced in Europe.
"With this postponement, we are not saying that the vaccine is problematic," Dr. Yong Poovorawan, head of Thailand's Center of Excellence in Clinical Virology at Chulalongkorn University, said in the Bangkok Post Friday.
"This postponement is to wait for verification whether there is any implication with the vaccine or that batch of the vaccine. That batch was produced in Europe. We use a batch made in Asia."
The European Medicines Agency stood behind the vaccine on Thursday, saying that blood clotting has only been seen in 30 cases.
The AstraZeneca vaccine has been approved for emergency use in more than 70 nations, including Canada and Britain. It has not yet been authorized in the United States, but there are tens of millions of doses at U.S. manufacturing facilities waiting for distribution.
"There is currently no indication that vaccination has caused these conditions, which are not listed as side effects with this vaccine," the agency said while acknowledging an investigation to see if there is a correlation is ongoing.
"The position of EMA's safety committee PRAC is that the vaccine's benefits continue to outweigh its risks and the vaccine can continue to be administered while investigation of cases of thromboembolic events is ongoing," the agency said.