The world of Tzu Chi May 2020 (Vol.122)

TZU CHI 122 09 What is a vaccine? Is it safe? Vaccines are generally categorized into three types. The first and second types are attenuated vaccines and inactivated vaccines respectively. These two types of vaccines are formulated from virus particles whose virulence has been suppressed or eradicated and are hence harmless to humans, but are capable of stimulating the immune system to produce antibodies that function to fight viruses in case of infection. However, scientists have raised concerns over the risk of injecting virus particles that have resisted the weakening phase, triggering symptoms of viral disease in the receiver of the vaccine. It is imperative to consider the hazards of each type of vaccine, as well as its advantages and disadvantages, before making decisions regarding its suitability. The third type of vaccine is known as subunit vaccines. Scientists extract the gene encoding for virus surface protein and use genetic engineering techniques to produce the protein as a vaccine before injecting the resulting vaccine into the human body. The vaccine triggers an immune response and stimulates acquired immunity against the pathogen from which it is derived. A subunit vaccine is formulated from a protein of the pathogen instead of virus particles. Hence, a subunit vaccine is only able to stimulate specific immunity against a specific protein from the viral pathogen and not other proteins. Note that a viral structure is usually composed of four to five types of proteins. Therefore, most scientists tend to opt for attenuated vaccines. How is research on virus vaccines conducted? Researchers usually start by studying which surface protein of a virus particle stimulates an antibody response in humans by examining antibodies in patients of the viral disease. After obtaining the relevant information, we will begin conducting genetic engineering procedures to produce a subunit protein of the virus and test the cell before moving on to animal testing. Mice are usually used in the animal testing stage for ease of breeding. Furthermore, mice reproduce quickly, easily multiplying the number of subjects for experiments. Mice used in laboratory research have to be bred in a controlled environment to prevent microbial infection, which affects the outcome of experiments conducted on the mice. To compensate for the differences between the genes of mice and that of humans, some laboratory mice are genetically modified and are particularly costly, ranging from RM10,000 to RM20,000, which explains the high costs involved in vaccine research. Every higher education institution has its own Institutional Animal Care and Use Committee (IACUC) to regulate the use of animals as subjects in laboratory experiments. Applicants are required to submit a research proposal detailing the types of animal species involved and the quantity of each, as well as the research methodology. The IACUC will review the proposal to assess the appropriateness of animal use in accordance with the guidelines and rulings stipulated by the Department of Veterinary Services of Malaysia (DVS). This ensures the ethical use of animals for research and protects the welfare of laboratory animals. Marching Forward Hand in Hand