Which vaccine should I opt for?

I recently had my vaccine shot and was elated, I went around spreading the joyous news to everyone I know. Not all my friends were happy to hear the news, I was shocked by their reaction, I soon realised that they were not alone and despite the plethora of information available, there are many with a lot of questions. I decided I’d do my share and start by answering the basic few

image source — https://www.paho.org/en/news/14-7-2020-countries-americas-pool-efforts-ensure-access-covid-19-vaccines

What are Vaccines?

Given the pandemic, most of you would’ve already been aware of this, yet this question is so important that I’d go ahead and reiterate it. Vaccines usually contain weakened or inactive parts of the virus that are injected to activate immune response. This helps the immune system get familiar with the virus so that when the body actually comes in contact with the actual virus, the immune system can immediately detect and act towards eliminating the virus.

What to expect from vaccines?

Now that we know what vaccines do, we naturally would expect that once vaccinated the virus would not cause a dent on our immune system, BUT that’s not the case. The vaccine only helps protect us once the virus enters the body. The second line of defence that our body poses to any foreign object entering the body is Inflammation, phagocytosis (engulfing the pathogen) and a rise in temperature. Hence these symptoms are merely indications that the immune system is fighting the virus/pathogen.

The best case scenario after the vaccination would be no infection and the worst case scenario would be loss of life.

The aim of the vaccine roll-out is to reduce the indications like serious organ damage, hospitalization and death and give the immune system enough help so that even if we do get the virus it would be more like a common cold.

Preventing any infection at all, is not the goal of the vaccine

Photo by Roger Starnes Sr on Unsplash

What does efficacy rate mean?

Efficacy rates are calculated based on the results from clinical trials. They are based on the number of people who were tested positive in the trial. Each clinical trial has the volunteers divided into 2 groups (Dummy treatment (placebo) and those who get the vaccine), say for example in a group of 160 participants who were divided equally into 2 groups, 80 people get COVID-19 and all of the 80 fall in the placebo group then, the efficacy of the vaccine is a 100%. If out of the 80 people 10 have received the vaccine and 70 fall in the placebo group then the vaccine has 94% efficacy.

When we say that a vaccine has 94% efficacy it does not mean that 6 out of 100 vaccinated people get COVID 19, it means that every individual who is vaccinated has a 94% chance that they won’t get any serious implications every time they come in contact with the virus.

Photo by Edwin Hooper on Unsplash

How do you know which vaccine is the best?

One factor that plays an important role in the efficacy is the timing in which the trials were performed, for example the Moderna and the Pfizer/BioNtech trials were performed entirely in the US during summer (Aug’20-Nov’20) 2020 when there was a drop in cases.

The Johnson and Johnson trial started much later (from Oct’20-Feb’21) when there were more chances for people to be exposed to the virus. It was also performed in other countries, especially South Africa and Brazil therefore including the variant strains as well.

The AstraZeneca trials were also performed (Jul’20-Nov’20) in various countries including Brazil and S.Africa.Unless the trials for all the vaccines were performed under the same conditions in the same countries, it isn’t fair to compare all the vaccines side by side.

When deciding which vaccine is the best, it is crucial to remember that the aim of the vaccine rollout is to end the pandemic and not to attain zero-infection. The goal is to reduce the chances of serious infection, hospitalisation and death, and every vaccine that is approved by the government reduces the serious implications by a 100%, hence it is important that we accept any vaccine that we are offered by the government.

Immunology graduate