What vaccines are being developed? How effective are they? And how exactly do they work? All your questions, answered.
Remarkably, a COVID-19 vaccine is now being rolled out across the UK – less than 12 months from a pandemic being declared. And not only that: vaccines from Pfizer, Moderna and Oxford University have shown to be many times more effective than first predicted – by above 90 per cent in some instances.
Now approved for use, the Pfizer vaccine is being administered throughout the UK. 90-year-old Margaret Keenan from Coventry was the first person to receive the jab after it was given the green light by the country’s medicine regulator.
Some 800,000 doses of the vaccine have been delivered to UK hospital hubs – enough for 400,000 people – but it is unclear when more doses will arrive from the manufacturer.
However, amid all the recent positive coronavirus vaccine news, several key questions still remain. When more vaccines be ready in the UK? How exactly do they work? And how will they be distributed?
Here’s everything you need to know about the coronavirus vaccines hopefully coming soon to an arm near you.
COVID vaccine UK: what vaccinations are being developed? How effective are they?
So far, four major vaccines have shown promising results in protecting people against COVID-19.
- Pfizer-BioNTech (mRNA)– After conducting their final efficacy analysis, the two drug companies announced their vaccine is more than 94 per cent effective in over 65s. The findings were based on a study of 41,000 participants around the globe. The jab has been approved for use in the UK.
- Oxford University-AstraZeneca (viral vector). The vaccine was shown to be, on average, 70 per cent effective in an analysis of phase 3 trial data. While administering two full doses of the vaccine a couple of months apart yielded 62 per cent effectiveness, a half dose followed by a full one later showed to be 90 per cent effective. While the Oxford team hope to have the vaccine rolled out by the end of 2020, the vaccine is yet to be approved in the UK.
- Moderna (mRNA). In a trial of more than 30,000 Americans, the vaccine showed to be nearly 95 per cent effective.
- Gamaleya (Sputnik V viral vector). In a press release, the Gamaleya National Center of Epidemiology and Microbiology in Moscow claimed a large-scale Russian study saw 92 per cent efficacy for its vaccine. However, other scientists have voiced concerns this claim is based on too few cases. Although the vaccine was trialled on 18,000 people, the efficacy claim has been based on an analysis of only 39 individuals to test positive with coronavirus.
Many other companies, such as Novavax, Valneva and Janssen are also developing vaccines, with major trial results yet to be announced.
How do the coronavirus vaccines work?
Although the inner workings of each complex vaccine differ, they essentially all use the same strategy to protect us from coronavirus: fooling our bodies into thinking we’ve been infected.
By doing this, it allows our immune systems to build a memory of COVID-19, meaning it is better prepared to fight against it in future.
Here are the four main types of COVID-19 vaccine:
Viral vector vaccines
This is the type of vaccine created by Oxford University-AstraZeneca. It works by injecting your body with a genetically altered common cold virus from chimpanzees (what’s called an adenovirus). This lab-modified virus can’t replicate in the body or harm it, but does carry the genetic instructions used to create the protein spikes or ‘crowns’ that can be found on the coronavirus. These spikes aren’t harmful in themselves – they’re simply what the coronavirus uses to latch onto cells.
After injection, the vaccine virus enters a human cell. There it uses the cell’s nucleus to ‘photocopy’ the genetic instructions of how to make the coronavirus protein spikes. This causes the cell to produce its own spikes, prompting the body’s white blood cells to attack it. This means that if confronted by a real COVID-19 outbreak, your immune system can recognise these spikes and has a tried and tested battle plan.
The type of vaccine developed by Pfizer, an mRNA works incredibly similar to a viral vector vaccine. Both are designed to prompt some of the body’s cells to produce coronavirus spikes – crowns that provoke an immune response.
However, the mRNA vaccine somewhat streamlines the process. Instead of forcing cells to ‘photocopy’ genetic instructions, the vaccine is a collection of instructions that enters a few of your cells.
These fragile genetic codes need to be stored at very low temperatures (the Pfizer vaccine requires -70°C). Viral vector vaccines, however, can be stored at regular fridge temperature.
Protein adjuvant vaccines
Like several other vaccines, the protein adjuvant approach relies on teaching your immune system to recognise COVID-19’s protein spikes. However, while the mRNA and viral vector vaccines work by making some of your own cells produce these crowns, this vaccine directly inserts protein spikes into the body.
“This involves purifying just one component of the virus away from everything else,” explains Dr David Matthews, virologist from the University of Bristol. “It’s essentially growing huge amounts of cells that are expressing spikes. And then purifying the spike away from every other part of the virus.”
Inactivated whole virus vaccines
As the name suggests, this vaccine inserts a dead or inactive version of COVID-19 into the body, triggering an immune response.
While simple in theory, these vaccines are incredibly difficult to produce. “The biggest problem you have here is manufacturing it,” says Matthews.
“You’ve got to make a lot of it. To make a huge amount of a highly dangerous virus and then kill it – making sure it’s definitely dead – is a massive task.”
Do the coronavirus vaccines have any side effects?
No significant safety concerns have been reported, but no drug, including paracetamol, is 100 per cent safe from extremely rare allergic reactions.
A COVID-19 vaccine will only be approved for use on the general population once it has met robust standards on safety through extensive clinical trials. It’s down to the UK’s medicine regulator MHRA (Medicines and Healthcare products Regulatory Agency) to authorise any vaccine, which it will analyse over several weeks.
Is there any serious worry that a vaccine could cause hidden long-term effects? “That is a potential problem with any drug you could imagine. But the technology to build many of these vaccines, such as the Oxford one, has been used before. It’s not like we’re guessing – we know exactly what we’re doing,” says Matthews.
“You also really have to ask: what are the long-term effects of catching coronavirus? Do you want to take a risk with a virus that can kill at all ages? Or do you want to take a vaccine for which we are as confident as we can be that there are no fatality risks?”
When will the coronavirus vaccines be rolled out?
The Pfizer vaccine has been approved for use in the UK. On 2 December, the government announced: “The vaccine will be made available across the UK from next week.” The first person to receive the coronavirus vaccine was 90-year-old Margaret Keenan, on 8 December.
The government has said the UK will have secured 10 million doses of the Pfizer vaccine for distribution in December 2020.
On 13 December, the lead researcher for the University of Oxford vaccine said the chances of it being rolled out by the end of 2020 are “pretty high”.
It is likely any approved vaccines will require two doses per patient, with a 21-28 day gap between doses.
How will the vaccines be distributed?
Although plans have not yet been finalised, mass vaccination clinics have been proposed. Venues such as sports halls, leisure centres and NHS Nightingale Hospitals have been earmarked as vaccination sites.
As the Pfizer-BioNTech must be stored at low temperatures, it is unlikely to be taken directly to care homes. However, it is hoped that the Oxford vaccine, which can be stored at fridge temperature, may not have to be administered in a hospital.
The government is also organising roving teams of healthcare workers who can visit care homes and housebound people.
The vaccine will likely be administered via injection, although there is some hope it can be distributed through a nasal spray.
“There are certainly good arguments for delivering a vaccine’s payload directly to the upper respiratory tract like modern flu vaccines,” says Matthews.
“That will raise an immune response at what’s called the mucosal surfaces – the surfaces of the nose, mouth and the back of the throat. That’s where you really want a strong and effective immune response if you’re going to beat off a respiratory virus.
“However, at the moment, inducing good immunity by such a spray is less understood than an injection.”
In what order will we get the coronavirus vaccine?
While the government has said the most vulnerable will receive the vaccine first, further details have not been announced. However, the Joint Committee on Vaccination and Immunisation (JCVI) has recommended a priority order, based on who is at the highest risk of death.
Their order is:
- Older adults in a care home and care home workers
- All those aged 80 and over and health and social care workers, though they may move up the list
- Anyone 75 and over
- People aged 70 and over
- All those aged 65 and over
- High-risk adults under 65
- Moderate-risk adults under 65
- All those aged 60 and over
- All those 55 and over
- All those aged 50 and over
- The rest of the population, with priority yet to be determined.
Source: BBC News