As news emerges of the phenomenal rate of COVID-19 vaccinations in the UK, many people wonder how each type of vaccine works.
There’s continuing good news about the rate of vaccination against the virus that shook the world in 2020. Though some people have lingering queries about the effectiveness of different types of COVID vaccines.
At the time of going to press, around 90% of adults in the UK had received their first dose. Approximately 70% had received both. When you consider that the vaccination programme only started seven months ago, it’s an astounding rate of health protection!
Are COVID vaccines successful?
Did you know that around 170 vaccines against COVID-19 were kickstarted? The ones being used achieved excellent results in human trials, and therefore secured official approval, in record time for the pharmaceutical industry.
The vaccines approved for use in the UK are currently: Pfizer, Moderna, Oxford/AstraZeneca and a Janssen one-shot option. Which one you get is usually based on available stocks.
Their effectiveness has been universally successful. In fact, all have outcomes slightly above expectations.
Though none offer 100% immunity – more like 90% – meaning other infection control measures are still required.
How do they vary?
The vaccines against COVID-19 currently in use or being developed fit into four broad categories.
Whole Virus
These vaccines deliver a small amount of the whole virus – either an inactive or weakened form – to trigger an immune response. They offer some complexities, including the potential for weakened ones to make people poorly if their immune system is compromised.
The technology and techniques involved have been highly successful for other diseases, but it’s a costly and lengthy process.
Protein Subunit
This is when just a purified part of the pathogen – key proteins – are used to trigger the body’s production of antigens.
It limits the chance of the person becoming ill, but may also limit their immune response level.
This too is a widely used way to combat viral disease and is safe for anyone with a compromised immune system. However, it’s an intricate and expensive development process.
Viral Vector
This type of COVID vaccine includes the Oxford University-AstraZeneca and Janssen ones.
It works by modifying the virus – which becomes the ‘vector’ – and using that to deliver a genetic message to cells, triggering the production of antigens.
This too has been used previously. In the past, scaling it up has been a sticking point. For COVID-19, pharmaceutical companies overcame this potential hurdle brilliantly.
Nucleic Acid (RNA AND DNA)
This fourth type of vaccine extracts genetic material from the virus – either RNA or DNA – to deliver instructions to cells to produce the antigen. For COVID, this focused on the viral spike protein.
Pfizer-BioNTech and Moderna are classed as mRNA vaccines.
This technology is relatively new, making the above two vaccines truly ground-breaking.
One of the advantages is it’s a cheap and quick way to create heightened immunity to COVID.
