Eight hours after getting the first dose of the vaccine developed by the British-Swedish company in collaboration with Oxford University, the person, whose identity has not been disclosed, showed symptoms of third-degree anaphylaxis like fever, shivering, convulsions, and hand numbness.

Anaphylaxis is a serious allergic reaction that is rapid in onset and may cause death. It typically causes some symptoms such as an itchy rash, throat or tongue swelling, shortness of breath, vomiting, lightheadedness and low blood pressure. These symptoms appear within minutes to hours.

The person was among 1,382 who were vaccinated on Sunday, the national Expanded Program on Immunization reported.

Another person vaccinated on Sunday showed symptoms of dizziness, restlessness and irritability after 30 minutes.

Both are being treated in hospital and are in stable condition.

Earlier there were at least 12 cases of second-degree anaphylaxis.

The mass vaccination began last Monday, and so far 11,605 medical staff and other frontline workers in 12 localities have received their first shot.

At least 10 European nations including Denmark, Iceland and Norway have suspended the use of the AstraZeneca vaccine following reports of severe cases of blood clots following shots.

The U.K., France, Australia, Canada and Mexico are among nations that have sought to reassure citizens about the benefits of getting the vaccine and have said they will continue their respective inoculation campaigns.

Vietnam has yet to have cases of blood clot, Professor Dang Duc Anh, director of the National Institute of Hygiene and Epidemiology and head of the immunization program, said.

Vietnam has ordered 30 million doses, and 117,600 arrived late last month. The country will receive another 4.1 million AstraZeneca doses through Covax by April. It is also negotiating with the U.S.’s Pfizer and Moderna and other vaccine manufacturers in Russia and China.

In the latest outbreak beginning on January 28 Vietnam has had 901 cases.