The science behind AstraZeneca vaccine simplified

Following a Zoom interactive meeting between Bishops of the Church of Uganda and some of the developers of the brand Oxford AstraZeneca Vaccine, myths about the vaccine have been demystified and conspiracies de-bunked. 

The meeting held on April 26 and which I had the privilege to chair was aimed at assisting Ugandan bishops to interface with the scientists behind the development of the vaccine. 

The first major issue of concern was what exactly the AstraZeneca vaccine was composed of. It was explained that the vaccine is a harmless and weakened chimpanzee virus called Adenovirus which cannot reproduce in our cells or cause disease, even a common cold! The vaccine contains the genetic instruction to produce the coronavirus spike protein found on the coronavirus that causes Covid-19. 

The vaccine also contains water, salts, sugars and chemicals commonly used in vaccines to make them stable and to be kept chilled. The coronavirus spike protein name is derived from the crown like features of the virus when seen under a high-resolution microscope. It was further emphasised that cells that contain the coronavirus spike from the vaccine trigger responses that activate our immune system to produce antibodies and killer cells that target it. 

In 2018 the World Health Organisation (WHO) proposed a possible pandemic code-named disease X. The vaccine scientists were able to switch to Covid-19 very quickly using the adenovirus vaccine platform by inserting the sequence of the spike protein gene as soon as it became available in January 2020. 

It was good to learn that the Oxford AstraZeneca vaccine was a vaccine of choice by the WHO in view of its being easily transportable in the global-, middle- and low-income countries unlike other vaccines, such as Pfizer and Moderna that require very cold temperatures. Several big and small donors pooled resources to fund the development of the AstraZeneca vaccine. 

It was reassuring to learn that as opposed to street talk and social media conspirators, the known side effects of the vaccines are mild or moderate presenting in form of flue like symptoms such as headache, aching, fever as well as pain and tenderness at the injection site. The vaccine does not subject the body to attenuation but wears out from our bodies after about five days leaving it ready to fight disease through the immune system. 

The experts dispelled the fears that the AstraZeneca vaccine was a microchip technology inserted into people’s bodies which would over time trigger some cataclysmic reactions. As regards the mutations of coronavirus, it was revealed that majority of them may not be virulent but in some cases like the South African and Brazilian variants, there may be a need for development of updated vaccines to protect against these variants, a process that was ongoing .

The good news was that although there were many negative reports associating this vaccine to blood clots, the real data in the field was showing that the vaccine was incredibly effective against severe diseases and potential deaths. In any case, it was argued that the risk of getting blood clots from the vaccine is far less than getting blood clots from the virus. Statistics were showing that out of every one million people, only four were affected by the rare blood clot incidence. Important to note was that women are less affected by the Covid-19 disease compared to men. Other factors including lifestyle and prevalence of co-morbidities are also linked to the difference seen between men and women.  As regards age, anybody from 18 years and above, including pregnant women, could take the vaccine but even more urgently those who are advanced in age and those with comorbidities since without the vaccine the bodies’ natural immune system may not be able to cope with the virulence of the virus. 

In a nutshell, the experts emphasised the importance of the vaccine by comparing Covid-19 disease to an exam that awaits us all. If you want to pass an exam you prepare for it adequately. 

Taking Astra Zeneca vaccine is like preparing for exams. When you catch the virus, the vaccine will help to trigger a chain reaction that will help you to pass the corona virus exam by fighting off the disease and not severely getting sick or dying. However, the vaccines are not 100 per cent protective although they prevent nearly everyone getting severely sick.

Fred Sheldon Mwesigwa is Bishop of Ankole Diocese.  

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