A cerebral oedema, or brain swelling, has been diagnosed as the cause of death of a woman in Prachuap Khiri Khan who died at home after getting a second shot of a different Covid-19 vaccine, the Public Health Ministry said.
Dr Chawetsan Namwat, director of emergencies, health hazards and diseases at the Department of Disease Control, said the results of an autopsy indicate she died of brain swelling from a clot, resulting in brainstem compression.
Phongsaphak Satthasophon, a 39-year-old private tutor, died on Tuesday, a day after receiving a shot of the AstraZeneca vaccine. She had the Sinovac vaccine as her first shot. She had high blood pressure.
The government has changed its vaccination approach by providing a second dose of AstraZeneca vaccine for those who received the Chinese Sinovac vaccine for their first shot.
The government insists the new approach will boost immunity against Covid-19 variants.
Dr Chawetsan said the ministry will further investigate to determine if the tutor's death was associated with the vaccination.
The doctor yesterday also gave an update on investigations into cases of vaccination side effects.
Between Feb 28 and July 18, a total of 1,592 cases of side effects were reported and investigations into 482 cases were completed. Of these 482 cases, 71 people developed allergic reactions while tests on 240 people who reported some side effects did not detect any anomalies.
Another 158 people, who showed adverse symptoms, including 122 deaths, were determined coincidental to the inoculation but the causes were not linked to vaccines. A further 13 cases were inconclusive.
Dr Chawetsan also explained how the efficacy of the Sinovac vaccine was calculated using a study by Chiang Rai Hospital which found the percentage of people who were fully vaccinated and contracted the virus was 7.1% while the percentage of those who did not get the vaccine and contracted the virus was 40.7%.
He said the infections of those who were not vaccinated were 5.7 times higher than those who were fully vaccinated. Based on an odds ratio, two doses of Sinovac vaccine was 82.5% effective against the virus.