COVID-19 VACCINE
Immunological Mechanism of Vaccine
The environment contains a wide variety of potentially harmful organisms, such as bacteria, viruses, fungi, protozoaand parasites, which will cause disease if they enter the body and are allowed to multiply. The body protects itself through various defence mechanisms to physically prevent the organisms from entering the body or to kill them if they do.
The immune system is an extremely important defence mechanism that can identify an invading organism and destroy it. Immunisation prevents disease by enabling the body to respond by attacking and enhancing the immune response more rapidly to a particular organism.
Each organism has unique distinguishing components, known as antigens, which enable the immune system to differentiate between ‘self’ (the body) and ‘non-self’ (the foreign material). The first time the immune system sees a new antigen, it needs to prepare to destroy it. During this time, the organism can multiply and cause disease.
However, if the same antigen is seen again, the immune system is activated to destroy the organism rapidly. This is known as adaptive immunity and vaccine utilise this mechanism.
Vaccines contain the same organisms that cause diseases. But they have been either killed or weakened to the point that they are not able to make us sick. Some vaccines also contain only a part of the bacteria or virus called as virulence factor. A vaccine stimulates our immune system to produce antibodies, exactly like we were exposed to the disease. After getting vaccinated, we will develop immunity to that disease, without having infection. So, our body will be able to fight future infections by the presence of specific antibodies towards the bacteria or virus. Unlike most medicines, which treat or cure diseases, vaccines only prevent them.
Vaccine Development Process
Production of vaccine starts with preclinical research. Preclinical research is not done with people. It assesses the features of a test or treatment. For example, the research may aim to learn if a device is harmful to living tissue. After preclinical research, tests and treatments go through a series of clinical trials. Clinical trials assess if tests or treatments are safe for and work in people.
Clinical trials have five phases.
Phase 0 - Phase 0 trials are the first clinical trials done among people. They aim to learn how a drug is processed in the body and how it affects the body. In these trials, a very small dose of a drug is given to about 10 to 15 people.
Phase I - Phase I trials aim to find the best dose of a new drug with the fewest side effects. The drug will be tested in a small group of 15 to 30 patients. Doctors start by giving very low doses of the drug to a few patients. Higher doses are given to other patients until side effects become too severe or the desired effect is seen.
Phase II - Phase II trials further assess safety as well as if a drug works. The drug is often tested among patients with a specific type of disease. Phase II trials are done in larger groups of patients compared to Phase I trials.
Phase III - Phase III trials compare a new drug to the standard-of-care drug. These trials assess the side effects of each drug and which drug works better. Phase III trials enrol100 or more patients. Randomization is needed to make sure that the people in all trial arms are alike.
Phase IV - Phase IV trials test new drugs approved by the Food and Drug Administration (FDA). The drug is tested in several hundreds or thousands of patients.
This allows for better research on short-lived and long-lasting side effects and safety. For instance, some rare side effects may only be found in large groups of people. Doctors can also learn more about how well the drug works and if it is helpful when used with other treatments.
Fighting Misinformation of Covid-19 Vaccine
Misinformation is hard to get rid of it because of social media’s ability to quickly share posts makes it easy for claims to spread widely. For example, news about six people died due to Pfizer/ BioNTech covid-19 vaccine trials. Sadly, people just read the header and ignore the content of the news. The truth is the reporter further explained that FDA previously confirmed the vaccine’s 95 percent efficacy rate andsupporting documents have proven that the drug is safe and may be used for emergency situations. In addition, the death of the participants during trials are associated with other underlying causes like obesity, arteriosclerosis and three of them are over the age of 55 which have low immunity level.
But we still should ignore the fact that vaccine also depend on every person’s immune reaction even though vaccine is generally safe for the majority of the population. The side effects of vaccine injection usually include pain, swelling, or redness where the shot was given, mild fever, chills, feeling tired, headache, muscle and joint aches. Serious side effects from vaccines are extremely rare. For example, if one million doses of a vaccine are given, only one to two people may have a severe allergic reaction.
Malaysia Covid-19 Vaccination
Malaysia will begin administering Pfizer's Covid-19 vaccine as early as February, with Prime Minister Muhyiddin Yassin among the first to receive the shot before front-liners. The government will also procure enough vaccines to cover more than 80 percent of the population. The vaccines will then be administered to front-liners before being given to high-risk groups such as the elderly as well as those with non-communicable diseases and chronic respiratory diseases.
The government has also signed an agreement with pharmaceutical company AstraZeneca to procure 6.4 million doses of its Covid-19 vaccine for 10 percent of the population. Also, the government inked a deal with Pfizer for 20 percent of the population, and a pact with Covax to cover another 10 per cent. In total, there will be enough vaccines for more than 80 per cent or 26.5 million of the population at a cost of RM2.05 billion.
Conclusion
The vaccine for COVID-19 has reached the end of clinical trials and is now being rolled out in multiple countries. This is a landmark moment. Building a biological barrier against the virus is now a possibility. A highly effective vaccine, used in combination with current physical barriers, raises hope that will bring an end to the pandemic is achievable.
Overall, this trial provided confidence in the vaccine’s efficacy and documented its safety. However, this does not mean that the study shows exactly what will happen in the real world. We cannot presume that the experiences of 19,000 vaccinated individuals will extrapolate to millions of people.
After all, vaccine is only a preventive mechanism, but themedias keep putting high hope for it. There are still many uncertainties that may happen in the future. For example, the vaccine may not be able to keep up with the rapid mutation of Covid-19 and this virus also may develop resistance towards the vaccine. We still need to continue adhering to the standard operating procedures (SOP) such as observing physical distancing, wearing face masks and washing hands even after receiving the COVID-19 vaccination. Thus, covid-19 vaccination is a solution but not an ultimate solution.
