Antibody tests, among staff at the Thai Red Cross Emerging Infectious Diseases Health Science Centre at the Faculty of Medicine of Chulalongkorn University, who were fully inoculated with the Chinese-made Sinovac vaccine, show rapid reduction of antibody levels, from 90% during the initial stage, to between 30% and 40%, said Dr. Thiravat Hemachudha, head of the centre, on his Facebook post today (Sunday).

He also said, however, that a study of antibodies among people who have received two doses of Sinovac vaccine, jointly conducted by doctors at the Central Chest Institute of Thailand and the National Centre for Genetic Engineering and Biotechnology (Biotec), shows that their antibodies measured 70% and are barely efficacious against the Alpha (UK) or Delta (Indian) coronavirus variants.

After having received two doses of Sinovac vaccine, he said that barely any frontline medics were found to be infected with COVID-19 initially and, even if some of them were infected, the symptoms were mild adding, however, that a while later, more medics were found to be infected, some with lung infections, but they survived “until this case.”

The “case” to which Dr. Thiravat was referring is that of a 30-year old nurse, posted on Facebook today by a Ms. Siwakorn Rattanakuntee, who worked in a hospital cohort ward and who died of COVID-19 infection five days after she fell ill, although she was fully inoculated with Sinovac vaccine.

Ms. Siwakorn said the victim would have survived had she been given a more effective vaccine, as she asked how many more frontline medics will fall victim to the disease.

Citing the nurse’s death, Dr. Thiravat reiterated the demand for a third booster jab of a different make of vaccine for frontline medics.

“Medics are not VIPs or a privileged class of people, but (the booster dose) will enable them to continue working to prevent the disease from spreading,” he said.

Meanwhile, Deputy Government Spokesperson Ms. Ratchada Thanadirek said, in her Twitter post today, that the CCSA has agreed to allocate some of the 1.5 million doses of Pfizer/BioNTech vaccine, donated to Thailand by the US government, for all frontline medical personnel, people aged over 60 and people afflicted with any of the seven underlying diseases.

The vaccine is due to arrive in Thailand this month.