A medical worker inoculates a patient with the Pfizer-BioNTech vaccine against Covid-19 in Crepy-en-Valois. Picture: Francois Nascimbeni/AFP
A medical worker inoculates a patient with the Pfizer-BioNTech vaccine against Covid-19 in Crepy-en-Valois. Picture: Francois Nascimbeni/AFP

Everything you ever wanted to know about Covid-19 vaccines but were too afraid to ask

By Opinion Time of article published Jan 20, 2021

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By Dr Jenny Laithwaite

This year we have all learned a lot of new words – from Corona to quarantine to spike proteins – and as much as we try to make wise decisions, the information overload can be really overwhelming.

Many people, for example, are concerned about whether the new Covid-19 vaccines that are becoming available are safe and beneficial – and many important questions have stemmed from these concerns.

What is in a vaccine?

There are many different vaccines being developed at the moment. Most of these are either mRNA vaccines (Pfizer and Moderna) or viral vector vaccines (AstraZeneca and Johnson&Johnson).

The active ingredient in each vaccine is a fragment designed to mimic the outer coating of SARS-CoV-2; none of them contain the actual virus or human tissue. Apart from the active vaccine ingredient, the vaccines contain the following:

* For the mRNA vaccines, lipids which coat the vaccine material to allow it to enter your cells.

* Some “buffering” chemicals, which keep the solution stable.

* The adenoviral vaccines will probably contain a preservative.

There is no evidence of any technology like chips or trackers being present in any of the vaccines.

Was the process hurried?

The development of these vaccines started long before 2020. SARS-CoV-2 is a member of the coronavirus family of viruses. These viruses have been known to cause diseases in humans and animals for many years. Following the outbreaks of SARS in 2002 and MERS in 2017/2018 (both caused by coronaviruses), scientists had already started work on vaccines that could be effective against these pathogens. The vaccines being tested now are an extension of this research.

One of the greatest limitations on vaccine development is funding. For once, the whole world has had an interest in developing a vaccine, leading to many groups of scientists being funded. Companies have seen it as worth their while to invest in having it on the market; philanthropists have been willing to contribute; and countries have pooled their resources to try to fast-track the development of these vaccines. This has made the process much faster than usual.

Usually a lot of scientific development is private and shared in journals that are not accessible to everybody. Something truly remarkable about this pandemic is the way so much research has been published “open source”, where anyone who desires can access it. The publishing of the genetic code for the SARS-CoV-2 virus spike protein on the 11th of January 2020 was a huge milestone and making it available to all researchers helped to get the process moving faster.

Each of the vaccines that have been approved for use has followed the accepted processes of being tested in Phase 1 (safety/dosage), Phase 2 (human safety) and Phase 3 (human efficacy) trials. They have been shown to effectively prevent a large percentage of those who received them from developing severe Covid-19 or dying from it. The side effects that they caused have been very mild. As the vaccines are rolled out to the public, they move into the next phase of surveillance, where their effectiveness and any new, rarer side effects are observed, reported and monitored.

Can the vaccine change your DNA?

The way your DNA works is by giving your cells a code to make proteins which build and shape the structure of who you are. None of the vaccines being studied can change this integral part of the cells in your body.

The mRNA vaccines work by entering your cells and giving them a message to produce a protein. This is the same protein that is found on the outside of the coronavirus. As your body notices this foreign protein floating around, it is stimulated to produce antibodies and T-cells which will then be ready to recognise this protein and fight it off if you are ever exposed to the real thing.

The viral vector vaccines use the shell of a virus that has been inactivated and had the Covid-19 outer protein added to it. As a result, it can’t enter your cells and replicate, but your body can learn to recognise the protein and again have antibodies and T-cells ready to fight off any future infection.

What about the side effects?

Over 200 000 volunteers have participated in vaccine trials and to date, as roll out of the first contender vaccines has begun, over 1.1 million people have received a vaccine.

The vaccines that have been registered for use, and those that have published stage 3 data, indicate that so far, the side effects of the vaccines are very mild. These include pain and redness at the injection site and fever and headache for a day or two after the injection. A few patients have had allergic reactions to the vaccines but as long as the vaccine is administered in a health facility, and the patient is observed for 15 to 30 minutes afterwards, this can be treated.

Being vaccinated can prevent a large percentage of recipients from becoming severely ill with the disease. This can benefit the patient personally by preventing them from developing the sickness, or making it a lot milder; and also the community as a whole by stopping the chain of transmission of the disease.

It has been an extraordinary year and the steepest learning curve in the medical sphere in particular. While there is still a long way to go, not least to achieve effective vaccine roll out, it is encouraging, to say the least, that we are facing 2021 with the option of being vaccinated.

* Dr Jenny Laithwaite is a Johannesburg-based medical practitioner.

** The views expressed here are not necessarily those of IOL.

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