COVID-19 VACCINATION
Channel: A Singaporean
Date: 02/02/2021

COVID-19 VACCINATION

Current Progress

Singapore is currently mainly focusing on inoculating seniors aged 70 and above, as well as vital workers in at-risk occupations.

The goal is for the whole population of Singapore to be vaccinated by the 3rd quarter of 2021.

How Do The Vaccines Work?

The Pfizer-BioNTech vaccine, which is approved for use here, uses a relatively new method involving mRNA, which is also what Moderna's vaccine uses. This method has not been used in any prior vaccines.

The vaccine works by utilising mRNA containing the genetic code of the Sars-CoV-2 virus (that causes Covid-19) to manipulate normal body cells to manufacture portions of the Sars-CoV-2 virus (but not the whole virus, as it could replicate if completed). These virus parts will trigger an immune response that can be sometimes quite severe. The mRNA is fragile and hence requires lower temperatures to stay functional, making the transport of such vaccines difficult.

On the other hand, Sinovac's vaccine is an inactivated vaccine, which is one of the more traditional forms of a vaccine, having been formerly used in the rabies vaccine.

Inactivated vaccines consist of pieces of killed Sars-CoV-2 virus, which when injected will also trigger an immune response. As the virus is dead, it is less likely to result in a serious immune response, resulting in less adverse reactions, but also lowering the efficacy of the vaccine as the immune system does not fight the virus when it is alive.

Overall, all vaccines will result in a person's immune cells learning how to recognise the Sars-CoV-2 virus and remembering how to defeat them, so that the immune system can respond faster and more effectively if the person gets infected by the virus for real.

Why the Elderly take Priority

As a person ages, their immune cells become less efficient, thus the elderly are most likely to develop severe complications when they get Covid-19. For instance, 80% of deaths in the US due to Covid-19 were adults aged 65 years and older.

Possible Adverse Effects of Covid-19 Vaccines

Worldwide, it was found that there were 11.1 anaphylactic reactions per million doses for the Pfizer-BioNTech vaccine, while there were 2.5 anaphylactic reactions per million doses for the Moderna vaccine. Anaphylaxis is defined as a serious allergic reaction to something.

In Singapore, out of the 113 thousand people vaccinated, 432 adverse reactions and 3 anaphylactic reactions were recorded.

Adverse reactions include injection site pain and swelling, fever, headache, fatigue, body aches, giddiness, nausea, and allergic reactions such as itching, rashes, and swelling of eyes or lips. Anaphylactic reactions include rash, breathlessness, lip swelling, throat tightness and giddiness, all of which are more severe than regular adverse reactions.

People suffering from adverse and anaphylactic reactions had all recovered after at most one day in the hospital. There are safeguards in place at vaccination sites to provide prompt treatment in the event of severe adverse reactions like anaphylaxis.

Contrary to some claims, mRNA vaccines do not modify cell DNA, as mRNA are basically instruction sheets for cells to produce virus parts that are destroyed after being read. This means that mRNA vaccines do not cause mutations and are relatively safe to use.

Why Should All Singapore Residents Get Vaccinated?

Singapore's economy is dependent on global trade and therefore must keep its seaports and airports open and operational at all times, exposing us to Covid-19 from the outside world. As global cases continue to climb and repeatedly reintroduce Covid-19 into the resident population, the only way to prevent the virus spread is to achieve herd immunity.

The herd immunity threshold is at about 80% to 90%, due to the emergence of more contagious variants from the UK and South Africa. Viruses cannot replicate themselves outside of a living host, so vaccinating the population can sever the spread of Covid-19 and reduce the mutation rate of Sars-Cov-2.

Who Cannot Take The Pfizer-BioNTech Vaccine?

The Pfizer-BioNTech vaccine is not recommended for children aged 16 or younger, pregnant women, the severely immuno-compromised, and people with a history of severe allergic reaction like anaphylaxis.