With the hype and tripe re Covax types...what are the facts?Sunday, December 26, 2021
There is the well-known saying…'a little knowledge can be a dangerous thing',... especially when one does not know that he doesn't know!
Our immune system is inbuilt in our body to fight and ward off intruders such as all foreign substances including infectious agents such as bacteria, viruses and fungi. The fight is carried out by antibody proteins and white blood cells known as killer T cells assisted by T helper cells.
Between those two sets of attacks, we fight off all intruders into our tissues.
What happens is the body recognises that these foreigners don't belong and therefore mobilises the army.
Clearly you would expect that if the body sees only one enemy, its response will be less robust than should it see several enemies or an army of intruders. Further, the body responds to repeat exposures by an increased response of outpoured antibodies and killer cells.
Using that basic logic, let's look at the coronaviruses scenario.
This is a group of viruses that have been around for ages, causing sinus, throat and lung infections. Depending on the variant, the symptoms can be a mild runny nose, to sore throat to lung irritation…cough, cold and finally pneumonia…with production of so much fluid and blood that you could drown in your own body fluids. This kind of disastrous outcome has been described from time to time…the Spanish flu in the 18th century, SARS, MERS in 19th/20th century and now COVID in the 21st century.
Do not for one moment think this is anything new. We have no doubt it has been around for millennia and participated in much of the recorded pestilences as well as beyond historical records.
We only learnt of DNA in the late 19th century (Miescher); and its structure unraveled mid-20th century (Crick & Watson); ...and of the structure of viruses in late 19th century by a scientist studying diseased tobacco plants. The first virus proved to affect humans was the yellow fever virus, but for thousands of years the measles and smallpox have stalked the earth.
Looking historically at the worst pandemics recorded, there are the plague (bacterial), Spanish flu (H1N1 virus), the HIV/AIDS virus; and now the coronavirus variant in the form of COVID-19.
It is possible that DNA and RNA first appeared around four billion years ago and evolved in the history of evolution of organisms to contain the information for the structure of the body. The DNA stores the information and hands it on to the RNA which instructs a whole line up of 'operators' along an assembly line to make proteins. The proteins made from our body information are ours. Any others are regarded as foreign and so fought off by the immune system as soon as they are detected.
Old vs New Technology
The modern fight against viral infection started when Dr Edward Jenner used cowpox exudate to introduce it under the skin so as to protect against smallpox, then the prevailing scourge. This was late 18th/early 19th century and the name vaccine came from Jenner's use of the term “variola vaccinae” to denote cowpox. After much infighting by doubting thomases, the efficacy of the use of the relatively mild virus to protect against infection by a more powerful one became accepted; and vaccinations took off as an important tool in fighting diseases.
That old technology was the same principle used in fighting yellow fever, polio, measles, mumps et al...that is: Obtain the virus, weaken or kill it, expose it to the body which recognises it as foreign and the body attacks and rejects it.
The greater the fight, the longer the memory and this long memory is stored more so in the killer T cells group, whereas the quick short-term response is greater by the antibodies.
The newest technology to be deployed has been today's approach to introduce into the body, the DNA and/or the RNA for a single protein which when made elicits the immune response of antibodies and T killer cells against that single protein.
It follows that should several protein DNAs/RNAs be introduced then a broader and more robust response would be developed.
What do we have?
The mRNA vaccine is the messenger that carries the information for a single protein, the spike protein on the coat of the COVID virus...Moderna & Pfizer.
The Johnson & Johnson as well as the Russian Sputnik vaccines contains a variant of the same spike protein…still a single protein.
AstraZeneca has the DNA for the spike protein in a similar common cold virus known as the Adenovirus…a single protein.
The Cuban Soberana vaccine exposes the binding site of the COVID virus so that several proteins therein are eliciting antibody responses.
The Chinese Sinovac and Sinopharm use the killed whole virus which exposes a vast array of foreign proteins to the immune system.
Which works best?
Only time will tell. Right now the better marketed has pride of place in the marketplace and results of trials on various populations have not given robust big data for accurately reliable effects.
On the surface, they should all prove effective and to my mind the one that exhibits several proteins will eventually prove, even if not more effective, at least longer lasting.
So let's wait to see the results from mother TIME.
Can they be mixed?
Even on a single protein, there are several aspects to that single entity that the body could have elicited an antibody. So each company preparing the DNA/RNA vaccines could have a varied content of antigenic stimuli eliciting several different antibodies. We would therefore expect that to follow one vaccine with another type would enhance the ability of the body's defence.
As we usually say, and certainly in this context,'the more fighters the greater the barrier!'
And indeed, the larger the variety of antibodies…'the greater the protective effect!'
Hence, it makes sense to mix them as we go for second and booster doses. That's the theory…the experience is yet to follow!
Meanwhile, just take any vaccine that's available. They all work!!!!!!
PS: why all this testing...and what do they really tell you?
If you have been infected or vaccinated, then it is expected that you will have antibodies circulating in your system.
However, if you want to know if you currently have the infection, the test that has to be done is to detect the viral proteins…the antigen test or to detect the genetic material (PCR-test). If either of these is positive then you most certainly have the disease and should be isolated (to prevent you spreading the virus) and treated.
NB: It is possible to get a negative antigen test whilst getting a positive PCR test. This is so because the protein antigen levels can be very low and is missed by the testing method. On the other hand, the PCR test amplifies the genetic material to more readily measurable levels and is the absolute gold standard for determining the presence of infection. Hence, because of the complexity of the PCR test, it takes hours as opposed to the antigen test which can give results in minutes.
These are the facts as we know them to date. Let's tone down the hype, discard all the tripe and rationally assess the Covax types!
Professor Errol Morrison OJ, MD, PhD, is a consultant physician and biomedical researcher.
Dr Andrew Wheatley MP, PhD, is a biochemical researcher and Member of Parliament.