Covid-19 and Vaccines – the controversies and benefits
There is so much emotionally charged chatter on the social media about the pros and cons of the Covid vaccines. Some people have very strong opinions against use of the vaccines, including all the conspiracy theories, which I don’t care to discuss. There is more than enough of that around. I’ll leave that for better qualified academics from reputable institutions (like the Mayo Clinic) to deal with:
First may I say that vaccines have dramatically changed the world in which we live. I have recently been reading the history of smallpox and how this dreadful disease, with a 30% mortality rate, has been eradicated around the world through vaccinations.
Many other diseases like polio, rabies, typhoid, measles, mumps, rubella, meningitis, and a host of other childhood illnesses have been eliminated or significantly reduced by the availability of vaccines.
Scientists have been battling to develop vaccines to HIV and malaria but so far unsuccessfully for various technical reasons.
Along comes Covid-19 and the world is faced with a highly infectious, rapidly spreading pandemic that could potentially have as devastating effect on the world as did the Spanish ‘flu of the early 20th century.
In spite of instituting social distancing, mask wearing, limiting social contacts and hand washing/sanitising, only limited success has been achieved in reducing the spread. For a long time, many people were opining that Covid was not much different to seasonal influenza.
Thankfully that opinion has died a natural death, as I am sure almost every person is aware of either a loved one, or friend, or colleague who has either been seriously ill with the disease, or has died. This is definitely no ordinary seasonal ‘flu.
Not only have over 2 million people died so far around the world, and we have by no means seen the end of the pandemic, but the number of people who have needed hospitalisation, and/or have had long term sequelae, is enormous.
This is definitely not a disease by which we want to be infected if we can help it. Left to itself, the disease would eventually burn itself out, but this could take years and many more millions of lives before that happened.
Enter the vaccine. Tens of thousands of scientists have collaborated in an unprecedented drive to develop a vaccine for this crisis.
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In the past, it has taken years for some of the vaccines to become available for various infectious diseases. But this time around, with the rapidity of spread of Covid, we did not have that luxury.
Thanks to modern genomics (the study of genetic make-up of organisms), genomic sequencing of the SARS-2 Coronavirus was accomplished very rapidly in a collaboration between Chinese and Australian scientists, within weeks of the virus being identified.
This information was released worldwide in the scientific community in scientific journals. This allowed the major drive around the world to rapidly begin the process of developing vaccines aimed at various parts of the virus.
Enter mRNA vaccines. The technology of using messenger RNA to direct cells to manufacture proteins has been around for around 30 years. It has been used for agriculture, and is being developed for use in cancer treatments.
In the past, deactivated viruses or parts thereof were obtained, then injected into the body, exposing the immune system to foreign proteins and forcing antibody formation. However growing and processing these viruses is tedious and inefficient.
With the mRNA technology, it was possible to manufacture relatively short strands of mRNA that code for the identical spike protein on the “docking station” of the virus, that allows it to attach to human cells and empty its viral RNA into the cell.
This vaccine mRNA is able to pass through the cell wall thanks to an envelope of lipids (fats), and enter the cytoplasm (not the nucleus where the DNA occurs) where it is transported to the ribosome – the protein making factory inside the cytoplasm.
Here, the vaccine mRNA induces the production of certain spike proteins, which are then extruded onto the surface of the cells, where they can then stimulate an immune reaction. The vaccine mRNA has no effect on the DNA, and has no long term effect on the cell, as after a short while the mRNA is broken down and disappears.
Although mRNA technology has been around for decades, only a few vaccines have been developed using this technology for influenza, Zika, rabies and cytomegalovirus infections. Perhaps this is the reason for the apprehension this time around.
However, in spite of the urgency to obtain a vaccine, no shortcuts in testing safety and monitoring volunteers for side effects, have been taken. These studies have been performed meticulously in many countries, including South Africa, amongst a large number and a wide spectrum of society.
Here is a good article about the vaccines from the highest authority on infectious diseases in the US – the Centers for Disease Control and Prevention:
The Oxford – AstraZeneca vaccine uses a “gutted” Adenovirus to deliver DNA which has been taught to make spike proteins. This technology has been used before for vaccines, so it is tried and tested in control of diseases. However the process of development of the vaccine has been slower.
Here is another very readable and reliable article:
What are the pros and cons of the different vaccines now available?
The Moderna and the Pfizer vaccine were first off the block. Both are mRNA vaccines, and thus are fragile. For this reason they have to be stored and transported at very cold temperatures otherwise they become ineffective.
The Moderna vaccine has to be kept at -200C and the Pfizer vaccine at -710C. This makes for practical difficulties in managing the storage, transport and distribution of these sensitive vaccines in resource constrained countries.
The AstraZeneca vaccine is much less fragile, and can be stored in an ordinary refrigerator. This reduces the cost and difficulty with storage, transport and administration of the vaccine.
What is the efficacy?
The Moderna and Pfizer vaccines are amazingly effective – around 95% effective after 2 shots. AstraZeneca vaccine is reported at around 70% effective after 2 shots, but is also much cheaper and easier to administer.
What of side effects?
Already tens of thousands of people have been vaccinated with the mRNA vaccines. Apart from temporary pain in the arm, fever and fatigue – good signs of immune reaction – there have been few other serious effects.
It is estimated that 1:100,000 people will have an anaphylactic reaction to the vaccine and this can be a life-threatening emergency if not treated immediately and appropriately.
(But to place this in perspective, an anaphylactic reaction to penicillin occurs in about 1:5000 people – that is 20 x more common than with the vaccine, but doesn’t stop doctors from administering life-saving penicillin where indicated).
What happens if a large number of people refuse the vaccine?
The best chance of bringing the pandemic to an end is through a large enough proportion of the population becoming immune. This is either by being naturally infected, with the potential for mass illness and multiple deaths (as we have seen now for the last 11 months), or to cut the process short by vaccinating sufficient numbers of the population to ensure “herd immunity”.
This happens when the virus is no longer able to transmit easily from one person to another because there are so many immune people that can block the transmission. It is estimated that around 70% of the population needs to be immune for that to take place.
The attitude that says: “I will let other people go for the immunisation but I won’t go because I will rely on their herd immunity” is rather selfish and irresponsible in my book.
(The same attitude goes for child immunisations for measles, mumps, rubella, HPV and a whole host of other vaccines. Countless thousands of children have been protected from death or severe disability by having their immunisations.
Serious epidemics of measles and other communicable diseases have occurred where war situations or anti-vaccers have influenced enough people to avoid vaccines, resulting in failed herd immunity).
We would all like to get back to some sense of normality – to be able to walk around without a mask, to socialise with family and friends, to go back to church, and public sports events. The sooner we all get vaccinated, the sooner that is likely to happen.
In the mean time – keep to the protocols.
Til next week.
Dave Glass
Dr David Glass graduated from UCT in 1975. He spent the next 12 years working at a mission hospital in Lesotho, where much of his work involved health education and interventions to improve health, aside from the normal busy clinical work of an under-resourced mission hospital. He returned to UCT in 1990 to specialise in obstetrics/gynaecology and then moved to the South Coast where he had the privilege of, amongst other things, ushering 7000 babies into the world. He no longer delivers babies but is still very clinically active in gynaecology. An old passion, preventive health care, has now replaced the obstetrics side of his work. He is eager to share insights he has gathered over the years on how to prevent and reverse so many of the modern scourges of lifestyle – obesity, diabetes, ischaemic heart disease, high blood pressure, arthritis, common cancers, etc. He is a family man, with a supportive wife, and two grown children, and four beautiful grandchildren. His hobbies include walking, cycling, vegetable gardening, bird-watching, travelling and writing. He is active in community health outreach and deeply involved in church activities. He enjoys teaching and sharing information.
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