The Second Domestic Case of 'Rare Thrombosis' Occurs... Man in His 30s Vaccinated with AZ Leftover Vaccine

On the 7th, medical staff at a hospital in Dobong-gu, Seoul, are administering the AstraZeneca (AZ) COVID-19 vaccine. [Image source=Yonhap News]

[Asia Economy Reporter Lee Chun-hee] The second case of 'rare thrombosis (thrombocytopenic thrombosis syndrome, TTS)' occurring after receiving the COVID-19 vaccine has been reported in South Korea.

The COVID-19 Vaccination Response Task Force announced on the 16th that the second confirmed case of rare thrombosis has occurred. According to the task force, the patient is a man in his early 30s who received the AstraZeneca (AZ) vaccine through leftover vaccine inoculation on the 27th of last month. Nine days after vaccination, on the 5th, he experienced severe headaches and vomiting, and his symptoms did not improve after medical treatment.

Twelve days after vaccination, on the 8th, his symptoms worsened and he experienced changes in consciousness. Upon visiting a higher-level hospital and undergoing tests, thrombocytopenia was observed, and brain imaging confirmed thrombosis and hemorrhage, raising suspicion of rare thrombosis. Subsequent antibody tests for confirmation were conducted during treatment, and on the 15th, the test returned positive. The patient is currently receiving treatment in the intensive care unit.

Following this, the task force held an expert consultation meeting on blood coagulation disorders on the 15th and reconfirmed that this case meets the criteria for confirmed rare thrombosis.

Previously, on the 31st of last month, the first domestic case of rare thrombosis was confirmed. This patient was also a man in his 30s, working in a vulnerable facility, who received the AZ vaccine. After vaccination on April 27th, he visited a medical institution on May 9th due to headache symptoms and received treatment. On the 12th, he was hospitalized due to seizures. Subsequent tests confirmed rare thrombosis, and the blood coagulation disorder advisory committee also clinically determined that the case met the definition of rare thrombosis.

As of midnight on the day, a total of 9,032,827 people have received the first dose of the AZ vaccine, and this is the second confirmed case of rare thrombosis, which corresponds to 0.2 cases per one million people. However, among people in their 30s, as of midnight on the 14th, 458,849 have received at least one dose, and two individuals in this age group have been diagnosed with rare thrombosis, resulting in an incidence rate of 4.4 cases per one million people.

However, a task force official stated, "Overseas, the incidence rate has been reported as 3 to 4 cases per one million people, or 1 to 2 cases per 100,000 people. Considering this, the domestic situation needs to be monitored further, but it is currently estimated not to be at a high level." According to the task force, the current incidence rates of rare thrombosis abroad are 9.5 cases per one million people in the UK (as of May 20) and 10 cases per one million people in the European Union (EU) (as of April 16).