Can this Trojan horse make it?
The Oxford University-developed vaccine, which has been licensed to British pharma major Astrazeneca, can best be described as deploying a Trojan horse strategy to stimulate the human system into building an immune response that can beat the Sars-cov-2. We explain how:
THE ‘VECTOR’
The vaccine uses what is known as a “viral vector”. The researchers took what’s called an adenovirus that causes cold in chimpanzees (and is thus harmless to humans) and bio-engineered it to include components of the Sars-cov-2.
WHAT THE VACCINE DOES
The Phase 1 trial report indicated that the vaccine was able to trigger an immune response at both levels: antibodies as well as killer T cells were found in the blood of inoculated volunteers.
PLATFORM: MRNA TRAINING THE BODY
This component is genetic material of the Sars-cov-2’s surface protein, also known as the spike ‘S’ protein. It is this that the virus uses to infect humans, and is also what antibodies bind to. Being exposed to this component – which is now innocuous because it comes with a virus that does not infect humans – will train the body to recognise it and act on it faster. might not be needed here.
‘DOUBLE PROTECTION’
This is significant because a T cell response indicates the immunity will last for a significant amount of time, since T cells and B cells (which produce antibodies) are part of the body’s second line of defence: the one that learns to fight an unknown pathogen and retains that information.
– This technique uses a lipid (fat) molecule to send instructions to the body to make copies of the Sars-cov-2’s spike protein, which is then detected as a pathogen that the body learns to fight A preliminary report published in the New England Journal of Medicine for the Phase 1 clinical trial showed that it generated an immune response in healthy adults and was generally well tolerated. The report involved the findings in 45 participants between the 18 to 55 age group.
Oxford and the Astrazeneca are now recruiting people for the ongoing Phase 2 and 3 trials to confirm their findings in different groups of people – including older age groups, those with other health conditions, and in ethnically and geographically diverse populations.
It will take at least a year to determine conclusively if the vaccine offers long-term protection, according to the Phase 1 trial report. This is because scientific ethics dictate that people cannot be deliberately exposed to a virus – researchers will instead monitor volunteers to see if they picked up an infection and how their body reacted.
Since this vaccine has been developed by a United Kingdom-funded university, UK will have intellectual property rights. Other countries, such as India, will need to enter into commercial deals or understanding via foundations such as
Coalition for Epidemic Preparedness Innovations (CEPI) and Global Alliance for Vaccines and Immunization (GAVI).
In a statement on June 4 2020, Astrazeneca said it has “reached a $750m agreement with CEPI and Gavi to support the manufacturing, procurement and distribution of 300 million doses of the potential vaccine, with delivery starting by the end of the year.”
PLATFORM: ADENOVIRUS VECTOR
This vaccine is very similar to the Oxford candidate in how it’s engineered. A key difference is that it uses an adenovirus that causes the common cold in human beings.
Phase 2 trials of this vaccine also published by The Lancet on Monday -- shows it is safe and effective too.