.png)
Venaya Binwani
Theme: Healthcare Issues and Disease
After a year filled with bad news, it is extremely exciting, and a great relief to hear that scientists are making leaps of progress in developing the Covid-19 vaccine. Just this week, it was announced that the pharmaceutical company Pfizer, and their biotechnology partner BioNTech, have developed the first variant of the vaccine that is eligible for mass administration. The UK has already ordered over 40 million doses to be administered to their population, and the immunisation process may be underway as we speak. [1]
Before the vaccine was approved, it had to undergo a series of clinical trials. The final phase involved 42,000 volunteers, half of which were given a placebo vaccine. Based on the results, the vaccine appears to be 95% effective, with only 8 out of the 21,000 participants who received the actual dose, falling ill. Out of those in the control group, 162 caught the virus, indicating that only 5% of all cases in this clinical trial occurred despite vaccination. The World Health Organisation claims that the effectiveness of this vaccine is highly successful, exceeding its approval threshold of 50%. [1]
The other lead competitors in the coronavirus vaccine race are Oxford University and their manufacturing partner AstraZeneca, as well as the pharmaceutical company Moderna. [2] These two vaccines are still awaiting results from phase 3 of clinical testing before they can obtain approval from Food and Drug administrations as well as the World Health Organisation. The Oxford vaccine is said to be about 62% effective, compared to the other two vaccines which are about 90% successful. Although, further testing shows that the Oxford vaccine may be just as effective following a booster dose. One significant advantage of the Oxford formula is that it does not need to be stored at extreme temperatures, as their American counterparts do. As the Pfizer and Moderna vaccines contain mRNA molecules wrapped in lipid particles, they need to be stored at -72 and -20 degrees Celsius respectively, in order to remain viable. On the other hand, the Oxford vaccine will be perfectly suited to temperatures between 2-7 degrees Celsius - which is about the temperature of any home fridge. On top of this, the Oxford vaccine is said to be much cheaper to produce, putting it in the lead in terms of accessibility. [2]
Pfizer, along with their drug giant competitor Moderna, have both developed more contemporary versions of the vaccine, compared to the Oxford researchers who have taken a more traditional approach. [2] Most vaccines in the past have involved injecting the host’s cells with a dead or weakened version of the harmful bacterium or virus, to trigger an immune response by the body. However, a more modern type of vaccine involves the use of mRNA. [1] mRNA is a strand of genetic material that corresponds to the genetic sequence found in part of someone’s DNA. It is the set of instructions administered to the protein manufacturing sites in the cell to construct a specific polypeptide chain. In the case of the coronavirus vaccine, researchers have been able to identify the mRNA sequence that codes for the spike protein on the surface of the virus - which makes it unique and identifiable to our body’s cells. In theory, a dose of the vaccine would allow our cells to begin producing the coronavirus spike protein. As the spike protein is ‘foreign’ to our system and is not normally present in the blood, they act as flags or signals to our lymphocytes and phagocytes, indicating that the body has been invaded. Once the immune system kicks in and destroys these foreign proteins, memory cells will be produced. Just as their name suggests, these cells will ‘remember’ the nature of the spike protein, and be able to react aggressively and rapidly to destroy the virus, if the coronavirus should infect the host person. Based on the clinical trials conducted, it appears that the vaccine will have to be prescribed in 2 doses, each 19-42 days apart. This secondary dose is used to essentially ‘train’ our immune cells to identify and destroy the coronavirus pathogen. Once our immune cells are accustomed to identifying a virus, it is very unlikely that a subsequent infection will cause people to present symptoms and fall ill. If you’ve read my articles before you know that I love an analogy, so perhaps this situation may help put the mechanism into perspective:
If a robber enters a bank and is caught by security - it is very unlikely that the same robber will be able to conduct another heist - if their picture is plastered all over the bank's walls.
The UK has been one of the first to approve the vaccine, with over 40 million vaccines already ordered. Health officials have announced that all vaccines will be managed under the NHS and they will not be able to be bought or sold commercially. Care homes stand as the UK’s top priority for immunisation, followed by other elderly groups and frontline healthcare workers. Pfizer is waiting for approval from other nations such as New Zealand, the USA and Japan, to begin rolling out vaccine doses across the globe. [1] In terms of Malaysia, our Science, Technology and Innovation Minister, Khairy Jamaluddin has already struck a deal with Pfizer, who will be supplying enough vaccines for 20% of the population. Once the vaccine undergoes clinical trials and testing on a local scale, results will be sent to the National Pharmaceutical Regulatory Agency. If approved, the country can begin its vaccination regime, and strive towards its 70% herd immunity threshold.[4]
It is pretty astounding how researchers have been able to develop, test and manufacture these vaccines in such a short span of time. However, much of this success is attributed to scientist’s prior understanding of the coronavirus family, which they have studied for years after the MERS and SARS outbreaks between 2002 and 2012. [3] Given all of this, there seems to be a beacon of hope that our world may go back to normal sometime in the foreseeable future. For now, all we can do is sit and wait - socially distanced and with our masks on of course.
References:
Lawton, G., 2020. Everything You Need To Know About The Pfizer/Biontech Covid-19 Vaccine. [online] New Scientist. Available at: <https://www.newscientist.com/article/2261805-everything-you-need-to-know-about-the-pfizer-biontech-covid-19-vaccine/> [Accessed 6 December 2020].
Gallagher, J., 2020. Covid-19: Oxford University Vaccine Is Highly Effective. [online] BBC News. Available at: <https://www.bbc.com/news/health-55040635> [Accessed 5 December 2020].
Gallagher, J., 2020. Oxford Vaccine: How Did They Make It So Quickly?. [online] BBC News. Available at: <https://www.bbc.com/news/health-55041371> [Accessed 7 December 2020].
The Edge Markets. 2020. Pfizer Covid-19 Vaccine Supply Issues Does Not Affect Supply For Malaysia — Khairy. [online] Available at: <https://www.theedgemarkets.com/article/pfizer-covid19-vaccine-supply-issues-does-not-affect-supply-malaysia-—-khairy> [Accessed 7 December 2020].
Glossary:
Lymphocytes: white blood cells which are involved in specific immune response
Phagocytes: white blood cells which are involved in nonspecific immune response