BioNTech and Pfizer’s mRNA coronavirus vaccines could be launched in New Zealand early next year, subject to final testing and approval. Photo / Provided
The mRNA coronavirus vaccine, which could arrive in New Zealand as early as next year, subject to final tests and regulations, will be the latest incarnation of the immunological revolution sweeping science. Professor Graham
Le Gros, the world’s leading immunologist and director of the Malaghan Institute of Medical Research, presented it for science reporter Jamie Morton.
First, can you explain what immunology really is?
When you experience a stimulus such as an infection, the immune system learns from it and adapts and adapts its various responses to be effective in neutralizing infectious ticks or viruses.
The most dramatic example of the immune system from the “real world” of this ability is the way it begins to make antibodies against infectious viruses that grow in our bodies.
From the start of transmission, the virus has preceded the game and the immune response has been largely ineffective.
Within a few days, however, the immune system begins to develop and increase the binding capacity of antibodies to the viral “spike protein”.
After three to five days, the deadly neutralizing antibodies are finally made by the immune cells which kill the virus.
And not only is our immune system capable of neutralizing all kinds of infectious agents, it also builds up a store of memory responses that last for most of our lives.
So, if we are ever infected with the same virus again, we don’t have to suffer the same suffering, and can fully cope with it and stay safe from further infection.
This is the basis of vaccination, where the components of the virus are created to stimulate a strong, long-lasting immune response to the virus so that you will stay safe from real infections for many years.
It’s very important to understand what this adaptive immune response is, and that’s what the immune system is designed for.
Because every pathogen or infectious agent is very different.
You have viruses, which are very small, bacteria, which are a little bit bigger, and then parasites.
If you think about what they present to the body, that is a very different challenge.
The immune system has developed very different ways of dealing with viruses, which live only within our own cells, and with bacteria, which sometimes reside outside of cells, and sometimes inside cells.
How does this new mRNA vaccine take this concept and apply it to something we can inject?
Basically, it takes components from the virus itself – It’s almost like getting one tiny piece of a viral infection.
In the case of Covid-19, it’s an RNA virus: you take a little of that RNA, you put it in, and in fact you are infected with a tiny fraction of the virus, looking as if it infected you.
But the RNA vaccine contains only the best part of the virus to neutralize the immune response against the virus.
It does not contain other parts of viral RNA that can kill our body cells, create fever, make us feel sick and allow the virus to replicate and spread to other people.
If you make your antibody’s immune response to a viral component susceptible to immune attack, then when the actual virus enters, it competes to neutralize the virus.
Why was this technology impossible 10 years ago? What has changed?
There have been some major developments.
One has come to understand how to use RNA, which is inherently chemically unstable, being naturally designed to have a very short half-life.
Learning how to further stabilize it, and how to actually protect it by wrapping it in special lipids and things like that, is a pretty big technological advance.
It helps us produce it, then store it so it can be shipped in a form that stimulates the immune system, and actually gets into cells.
Another big leap is identifying what it takes to get that RNA inside the cell, because if it’s outside, the RNA can’t actually do anything to stimulate an antibody response.
Do you see this vaccine setting the new standard? Or is there still room for our traditional types of vaccines?
First, I need to point out very strongly that we don’t yet know whether this RNA vaccine will actually stimulate long-term immunity in a person.
And there may still be room for those traditional protein-based vaccines.
Protein vaccines are easy to administer, and suitable for developing countries without health infrastructure such as refrigerators for storage. The RNA vaccine will always be problematic in terms of its stability around manufacture, storage and transportation.
If an RNA vaccine could be made to overcome these obstacles then it would be best.
That’s because no matter what pandemic happens – or whatever infectious agent comes in – they offer a very fast and effective way to quickly design and build a vaccine against something we’ve never seen before.
Additionally, they may ultimately be easier to manufacture and involve fewer additional components, or adjuvants, to enhance the immune response.
There is already some misinformation out there surrounding mRNA vaccines and genetic engineering. Why is this not the same as genetic modification?
Because vaccines do not carry out genetic modification in our body cells.
The RNA vaccine is simply a viral component that is only able to temporarily produce certain viral proteins in our cells, as viruses do, but without side effects.
RNA vaccines do not have the ability to integrate with DNA, or change the host DNA.
The RNA vaccine uses only the cellular machinery of our bodies the way the common cold virus uses in everyday infections.
What else could we possibly do to target this vaccine?
This technology was originally based on an attempt to create a cancer vaccine.
The recent developments that have been made to the RNA vaccine for Covid 19 could mean that we have now learned enough so we can get back to that big one – how to make a vaccine for all solid tumors for which there is no solution at this point.
But I think using it to treat all kinds of infectious agents is good too.
Whether it can work against parasites is unclear, but there are certainly many who suggest it will be effective against viruses.
If it passes the test, the global population will have a powerful and modern way to make a vaccine that can surpass our 30 year old technology for seasonal influenza, which remains a major global burden.
The RNA vaccine could ultimately be a great solution to some of the major global health problems we face.