The novel coronavirus has infected over 7 million people worldwide with over 400,000 deaths and it doesn’t look like it is stopping anytime soon. We are not even over the first wave of destruction yet. The only strategy which might mitigate and eventually eradicate this deadly virus from the world is a vaccine.
How do vaccines work?
Vaccines are probably one of the greatest known inventions of science. Vaccination is the safest and most effective way to protect people from infectious diseases. Thanks to vaccines some of the most deadly diseases such as polio and small pox are now almost eradicated from this planet.
Vaccines train the human immune system to recognize and fight pathogens such as bacteria and viruses without exposing the body to the disease symptoms. Vaccines are made of inactivated/ dead or weakened form of the pathogens (antigens). They can’t cause an infection, but when the immune system is exposed to them, it still sees them as a foreign particle and produces antibodies in response. Many of these antibodies will breakdown, however our immune system stores this information about the pathogen in the memory cells in the immune system. If the body encounters that pathogen or antigen again, the lymphocytes produce antibodies fast and strike down the invader before it’s too late.
Vaccines can also work at the community level by the process of herd immunity, a word made famous by UK in the recent pandemic. If a few individuals in the population are unable to be vaccinated for any reason (may be because they are too young or are immuno compromised) they can still be protected if everyone around them is vaccinated. In other words, they’re unlikely to even come in contact with the disease because everyone around is vaccinated!
Vaccine for SARS-CoV2
Vaccine production is a complex and laborious process which can take anywhere from 10-20 years from conception to approval. The global search for a vaccine for the novel coronavirus is underway. Currently there are 10 candidate vaccines for coronavirus in clinical evaluation and over 100 others in the stage of preclinical evaluation. A team of researchers from University of Queensland (UQ) in Australia might be leading the way in the quest and if successful we might have a vaccine by 2021 (12-18 months). There seems to be a faint light at the end of this very dark tunnel after all.
Molecular Clamp technology
Molecular clamp technology was invented by three UQ researchers Dr Keith Chappell, Dr Daniel Watterson and Professor Paul Young.
Enveloped viruses like SARS-CoV2 are covered with proteins called “spike” proteins (those little protrusions you see all around the virus), which are coiled up like tiny springs. Spike proteins are designed to aid the virus to bind to a host/ human cell and undergo a conformational change (coiled to uncoiled), making a hole in the cell wall that lets the virus in. Our immune system works by recognising that protein and making antibodies to kill it.
Logically, you want your immune system to recognise and make antibodies against the coiled shape of the spike protein. That way you attack the virus before it enters the cells and secondly after the virus enters the cells the spike protein changes its shape and some of the regions which are normally well recognised by our immune system gets hidden. Therefore, we essentially want to lock the virus with the spike protein in the coiled shape. That is where molecular clamp technology comes into action. These “clamps” are tiny pieces of protein that fix the spike protein in its coiled shape. These clamps prime the immune system to generate not one but many different antibodies to attack the virus making it more potent and efficient.
The bouquet like image on the left shows the structural model of the trimeric SARS-CoV-2 Spike protein (prepared by Dr.Daniel Watterson), stabilised by the Molecular Clamp (red). The potential vaccine is undergoing preclinical trials at this stage with Phase 1 clinical trials starting soon.
With accelerated timeline for the development of this particular vaccine for SARS-CoV2, it is estimated that the vaccine will be ready by end of 2021 if all goes well.