Professor Albie van Dijk, a professor at the North West University (NWU), has answered a few questions about vaccination and the Covid-19 vaccines that are available.
After 42 years of experience in molecular virology and biology, biotechnology research focused on vaccine development and biochemistry, she is an expert in the field of vaccines.
What is the typical timeline for the development, approval and availability of vaccines?
15-20 years. The availability of the first Covid-19 vaccines within one year is truly a unique one-off special human achievement and just shows that if there really is a will, there is a way. The uniqueness of the approach was that all the processes, research, development and scaling up were carried out at full steam in parallel and that money was not a bottleneck.
Countries have made unlimited unprecedented funds available. Clinical data were evaluated in time and consent could therefore be given very quickly.
What is the difference between nucleic acid, viral vector and protein based vaccines?
The result of the different approaches is the same. In all three cases, the vaccines instruct our cells to produce the spike protein “spike” against which the body then launches an immune response that protects us when we are infected with SARS-CoV-2.
Nucleic acid vaccines
The Pfizer-BioNTech and Modern vaccines use this technology. Ribonucleic acid, RNA, which is encoded by the salivary protein and packaged and injected into a fat bulb The body’s cells then use the RNA to produce the salivary protein. The salivary protein acts as an antigen that stimulates the production of antibodies.
The immune responses last long, months and sometimes even years, but the RNA is broken down within a few days. Viral vector-based vaccines AstraZeneca, Oxford University, Johnson & Johnson and the Gamaleya Research Institute’s Sputnik V vaccines use this technology.
The vehicle with which the genetic instruction for the synthesis of the salivary protein is inserted into the cells is in this case a harmless virus that contains the DNA form of the instruction. The cells then produce the salivary protein that acts as an antigen that stimulates the production of antibodies.
Protein-based vaccines Candidate Novavax, Sanofi and Bektop’s vaccines use this technology. These vaccines contain portions of either viral proteins or whole virus proteins that elicit a protective immune response.
Is it possible that nucleic acid or viral vector-based vaccines could have an effect on the genetic composition and function of cells?
No, not the ones that are now/are being developed for Covid-19. A number of vaccines are already in use in other countries, including nucleic acid/RNA (Pfizer/Moderna) and protein-based (Astrazeneka) vaccines.
Apart from availability, which of these available options would you consider to be the best for South Africa?
All the options will be able to work in South Africa. However, the cold chain, price (as estimated on 1 December 2020) and dose are also very important factors to consider. Modern (2 doses, $ 37 each, -20°C); Pfizer and BioNTech (2 doses, $20 each, -70°C); Sputnik V (2 doses, $10 each, +4°C); Johnson & Johnson (1 dose; +4°C; 10%); AstraZeneca (2 doses, $4, +4°C).
With the new variant (501.V2) of Covid-19 spreading in South Africa, how would this variant affect the effectiveness of immunisation?
According to the WHO, there are currently no indications that the variant has any significant impact on the susceptibility of the virus to any of the treatments, medications or efficacy of the vaccines that have been/are being developed.
The YouTube video of prof. Vincent Racaniello gives a brilliant explanation of this:
There has been considerable criticism in the past week against the government’s seemingly sluggish attempt to obtain vaccines for the country’s population. Is this criticism justified?
Yes, the subject was very opaque. It is a real pity that SA has not been very serious about obtaining vaccines for a long time.
This article was translated from Afrikaans and republished from Potchefstroom Herald with permission