11 July 2024

Human trials of the first Thai COVID-19 vaccine, developed by Chula Vaccine Research Centre (CVRC) at Chulalongkorn University and King Chulalongkorn Memorial Hospital, began today (Monday).

Called “ChulaCov19”, it is the first vaccine developed in Thailand, but will be the second to be locally made, if approved, after Siam Bioscience’s production of the UK’s AstraZeneca vaccine.

It is also an mRNA vaccine, a type that provides instructions to human cells on how to make a “spike protein” that triggers the body’s immune response.

The vaccine is being administered to healthy volunteers in two phases, under the close supervision of specialised doctors, nurses and researchers at King Chulalongkorn Memorial Hospital, according to Professor Dr. Suttipong Wacharasindhu, the hospital’s director and dean of the Faculty of Medicine at Chulalongkorn University.

The first phase involves 72 volunteers. Half are aged 18-55 and half 65-75. Some of them will get 10 micrograms (mcg) of the vaccine, while others will get 25mcg and 50mcg, to determine the most effective dosage. The second phase, involving 150-300 volunteers, will begin in August, if the first phase results are satisfactory.

If both phases of the trial prove high efficacy and safety of the vaccine, the third phase can be skipped and it could be approved for mass production before mid-2022, said Dr. Suttipong.

Prior to the human trials, the CVRC conducted experiments in monkeys and rats, with a high rate of success in preventing the virus from entering their system, according to Prof. Dr. Kiat Ruxrungtham, Scientific Mentor & Founder of CVRC.

When tested for heat tolerance, it was found that the vaccine can be kept in a refrigerator at 2-8oC for three months and can last two weeks at room temperature. It can be manufactured quickly, without the need for massive facilities.

With support from Thailand’s Public Health Ministry, the National Vaccine Institute, other state agencies, the private sector and civil society, the Thai vaccine researchers have also received support from Prof. Drew Weissman, of Pennsylvania University, a physician-scientist specialising in RNA biology who laid the groundwork for the COVID-19 vaccines developed by BioNTech/Pfizer and Moderna.

The CVRC will carry out further experimentation of the vaccine in animals, alongside the human trials, to prepare for mutations of the virus. If the experiments go according to plan, human trials of the vaccine on prominent variants, such as Alpha, Delta, Gamma and Beta, will be conducted in the last quarter of this year, Dr. Kiat said.