Newswise — August 16, 2021 – Chulalongkorn Memorial Hospital, Thai Red Cross Society, and the Vaccine Research Center, Faculty of Medicine, Chulalongkorn University (CVRC) held a press conference on the progress of clinical trials for the Thai “ChulaCov19” mRNA vaccine.  The clinical trial (Phase 1) was administered in healthy volunteers who are found to have good immunity after they have been vaccinated. The volunteers’ antibodies have been greatly boosted to prevent the original strain of the virus, and four other variants, namely Alpha, Beta, Gamma, and Delta. Manufacturing and preparation for registration to be used in an emergency are underway.

Professor Suttipong Wacharasindhu, M.D., Director of Chulalongkorn Memorial Hospital, the Thai Red Cross Society, and Dean of the Faculty of Medicine, Chulalongkorn University explained that since the onset of the COVID-19 pandemic in Thailand, Chulalongkorn Memorial Hospital and the Faculty of Medicine, Chulalongkorn University have assured the public that its facilities, personnel, and state-of-the-art technology can be used efficiently in the screening and treatment for members of the public.  Also, CVRC, the medical research institution that prides itself in the collaborative efforts of medical researchers and scientists who have worked on developing vaccines to serve the needs of the people both at the national and international levels, has started the first phase of the clinical trial for ChulaCov19 vaccine on a number of volunteers on June 14, 2021, under close supervision of a team of highly qualified medical practitioners.  The first batch of volunteers was found to have an excellent level of antibodies and are safe.

It is gratifying that the development of ChulaCov19 vaccine is advancing as planned and gaining the public’s confidence in the safety of the testing process.  We have to thank the Ministry of Health, the National Vaccine Institute, CVRC, various government, private and public agencies, and medical researchers and scientists both nationally and globally for their cooperation that made the ChulaCov19 vaccine development a success and ready to be tested in volunteers in the next phase.  This will bring tremendous benefits and fame to Thailand on the international stage.


                                        Professor Kiat Ruxrungtham, M.D., Director of CVRC
Professor Kiat Ruxrungtham, M.D., Director of CVRC


Professor Kiat Ruxrungtham, M.D., Director of CVRC added that the development of the ChulaCov 19 vaccine was made possible with the support from the government, private and public sectors such as the National Vaccine Institute, the National Research Council of Thailand, Chulalongkorn University’s Second Century Fund, and donations from the Faculty of Medicine Alumni Association’s Vaccine Research Fund, the Red Cross Society of Thailand.  

ChulaCov19 vaccine was designed and developed by a team of Thai researchers working collaboratively with Pennsylvania University’s Professor  Drew Weissman, a physician-scientist who shares similar determination in making the mRNA vaccine technology more accessible to people especially in countries with moderate and low incomes.


                                        ChulaCov19 vaccine

                                                                            ChulaCov19 vaccine


ChulaCov19 vaccine creates tiny particles of the Corona Virus’ genetic material mRNA (without using the virus itself) to signal the body to make spike protein to enter host cells and boost them to build immunity to combat the virus once people come in contact with it.  After this mRNA has performed its role of enabling the body to develop the protein within six days, the mRNA will disintegrate and not leave any build-up in the body whatsoever.  

Prior to this, the CVRC had been successful in its trial on monkeys and mice where the vaccine was found to prevent the virus from entering the bloodstream and increased the level of immunity significantly.  This led to the manufacturing and clinical trials in the first phase starting on June 14, 2021, for 72 volunteers from two age groups: 36 volunteers aged 18-55 years, and 36 volunteers aged 65-75. 

Both groups were divided into sub-groups, each with a different dosage of 10, 25, and 50 micrograms.  This is to determine the dosage at which the ChulaCov19 shows the greatest efficacy since at present, Moderna’s dosage is 100 micrograms while Pfizer is 30 micrograms.  The CVRC will need to find out whether the dosage for Thais or Asians should be 10, 25, or 50 micrograms to ensure safety while increasing immunity levels.  The second-phase trial is expected to be administered to 150-300 persons starting in August 2021.

The good news from Phase 1 clinical trial is that the subjects, after having received the second injection for seven days, showed mild to moderate side effects, localized pain in the injected arm, fatigue, fever, and chills, but the symptoms improved within one to three days on average. Also, it was found that ChulaCov19 could boost high antibodies immunity against the original strain of the virus.

In addition, the vaccine can inhibit all four mutated strains: Alpha, Beta, Gamma, and Delta by more than 80%, while boosting T-cell immunity which helps to eliminate and control the pathogen in the cells of infected people as well.


Other outstanding qualities of the ChulaCov19 vaccine

  1. Vaccine temperature endurance tests showed that ChulaCov19 could be stored at 2-8 degrees Celsius refrigeration for as long as 3 months and can also be kept at room temperature of 25 degrees Celsius for two weeks.  This makes the vaccine much easier to store than other types of mRNA Covid-19 vaccines.  
  1. The results of the animal trials have been very good.  The mice that had been modified to have the ability to contract Covid-19 showed that after being fully vaccinated with 2 doses of ChulaCov19 vaccine at 3-week intervals, and exposed to COVID-19 virus via their nose, the rats were prevented from contracting the virus and having the virus entering their bloodstream.  The vaccine also could reduce the level of viruses in the nose and the lungs by at least 10,000,000 times.  When tested, toxicity was at a safe level.  The mice that did not receive the vaccine would contract Covid-19 within 3-5 days and all of them showed a high level of infection in the bloodstream, in their noses as well as in their lungs.
  1. Since there is no need to wait for the virus to be cultured, the mRNA type of vaccine can be manufactured very rapidly.  With the mRNA vaccine, one simply needs to know the variant of the virus to be able to design a vaccine that can be synthesized in a test tube within 4 weeks and able to be tested in mice. With the short manufacturing turnaround, this means there is no need for large-scale factories since the synthesis for another vaccine can also take place when the virus mutates.  The CVRC has prepared for animal trials of the second batch of vaccine alongside the aforementioned first batch clinical trials in case of drug resistance or mutations – a matter that is a cause of immense concern all over the world with the emerging variants such as the English, Indian, South African and Brazilian.  The ChulaCov19 vaccine has been designed, developed, and manufactured by Thais and enjoys excellent support and collaboration from all relevant sectors. If things proceed as planned, it is hoped that a vaccine capable of preventing mutated and drug-resistant variants can be tested on volunteers by the fourth trimester of this year.  


The challenge for Thais should we want at least one of the four vaccines currently being researched and developed, including the ChulaCov19 mRNA vaccine, is to be registered and widely available before the next Thai New Year – April 2022.  Thailand must have clear goals  in the following four areas and must earnestly move them forward at the same time:

  1. There must be a system to raise sufficient funds from the government, private and public sectors with clear objectives, and allocation of the funds should be efficient and speedy. Each group of key stakeholders must meet and talk regularly without being stuck in the traditional government framework.
  1. The Food and Drug Administration (FDA) should speed up the drafting of rules and regulations for the registration of vaccines produced in Thailand stipulating the amount of research needed or follow the criteria similar to that of Taiwan. Definite requirements and guidelines must be spelled out by September to ensure prompt execution.
  1. The local vaccine factory is speeding up the production of ChulaCov19 mRNA for testing in Phase 2 B or Phase 3, then expand the production to millions of doses for registration and actual use.
  1. The government must approve a pre-purchase policy to allow vaccine developers enough funds to reserve raw material for vaccine production, which will take at least six months to complete. If Thailand is serious and operates efficiently, we believe that Thai people will have at least one vaccine developed by Thais before the next Songkran holiday.


                                       Chula Vaccine Research Center