COVID-19 vaccine UK: Everything you need to know about the new coronavirus jabs
With three vaccines approved for use across the UK, another jab, this time manufactured by Novavax, has shown promising efficacy data.
In a large-scale trial across the country, the Novavax vaccine has been shown to be 89.3 per cent effective. If approved for use, the government has said it expects 60 million doses to be delivered later this year.
Currently, the Pfizer, Moderna and Oxford University vaccines are approved for use throughout the UK. They have been shown to be many times more effective than initially predicted – by above 90 per cent in some instances.
On 30 December 2020, the Oxford University vaccine was approved for use in the UK and the first doses were delivered on 4 January 2021. The Moderna vaccine was approved on 7 January, while Pfizer vaccine, the first to be rolled out, was approved on 2 December 2021.
More than 7 million people have now received their first dose of a vaccine, with over 400,00 receiving a second dose. The UK government is aiming to offer 15 million vaccinations by mid-February.
However, amid all the recent positive coronavirus vaccine news, several key questions still remain. When will more vaccines be ready in the UK? How exactly do they work? Will they be effective against new coronavirus variants? 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, six 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 and delivery has started.
- 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. The jab has been approved for use in the UK and it is currently being administered across the UK.
- Moderna (mRNA). In a trial of more than 30,000 Americans, the vaccine showed to be nearly 95 per cent effective. This vaccine has been approved for use in the UK, with delivery expected in the spring.
- Valneva (inactive whole virus). The vaccine is being trialled on 150 volunteers at testing sites in Birmingham, Bristol, Newcastle and Southampton. If these tests show the jab produces an effective immune response to the virus, a larger trial of 4,000 UK volunteers is planned for April 2021.
- Novavax (‘subunit’ or protein adjuvant). The vaccine has been shown to be 89.3 per cent effective in large-scale UK trials. Significantly, it is the first jab shown to be effective against the new UK variant of COVID-19 in such a trial. The government has ordered 60 million doses of the jab, which will be produced Stockton-on-Tees, England.
- 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 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.
mRNA vaccines
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 SARS-CoV-2’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.
Read more about coronavirus vaccines:
- Coronavirus vaccine: Is it safe?
- Should we infect people with COVID-19 for vaccine research?
- COVID-19: Who should get a vaccine first?
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?”
Will the vaccines work against the new emerging variants?
Several major coronavirus variants have identified in recent weeks. These include:
- The UK coronavirus variant. A study has shown the Pfizer vaccine appears to protect against this variant, however, the results have not yet been peer-reviewed. Plus, the yet-to-be-approved Novavax vaccine has shown an 89 per cent efficacy in large-scale UK trials.
- The South Africa coronavirus variant. A study from Pfizer has indicated their vaccine is effective against this strain. However, these findings have not yet been peer-reviewed
- The Brazil coronavirus variant. No large scale trials or significant studies have yet emerged examining vaccine efficacy against the virus.
Read more:
When will the coronavirus vaccines be rolled out?
Many of the approved coronavirus vaccines are currently being administered across the UK.
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.
Almost a month after the rollout of the vaccine developed by Pfizer, the jab from the University of Oxford and AstraZeneca was approved and in January 2021 began being administered in hospitals and GPs across England.
Though approved on 7 January, the Moderna vaccine is not expected to be rolled out before the spring.
How are the vaccines being distributed?
More than 50 mass vaccination centres have now opened across the UK. There are now also more than 70 pharmacy services now operating across the country.
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. A team at Swansea University are working on a prototype for a COVID-19 vaccine ‘smart patch’.
“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.
However, experts have warned that the general public should not get their hopes up that life could return to normal once the high-risk had been vaccinated. Social restrictions may have to continue until around 50 per cent of the population has received the vaccine.
For further analysis, check out our ‘Will COVID-19 be over by 2022?‘ explainer.
Can the vaccines be mixed?
Not currently. If you are given a dose of the Oxford jab, your second dose must also be Oxford. The same goes for the Pfizer coronavirus vaccine.
However, Dr Mary Ramsay, head of immunisations at Public Health England has said, on “extremely rare occasions” the same vaccine is not available, or if there is no record which jab a person received first, a different vaccine may be administered for the second dose.
However, scientists have also said there is likely no harm in receiving two doses of different vaccines. Clinical trials mixing different types of vaccines are planned but there is no data as of yet.
Will we get a choice about which vaccine we are given?
As things stand the vaccines will be rolled out as and when they become available.
People are not able to choose which jab they want to receive.
How many coronavirus vaccines have the UK ordered?
The UK government has secured orders for millions of doses of several different vaccines.
These include up to 100 million doses of the AstraZeneca/Oxford University coronavirus vaccine, enough for the majority of the UK’s population of 66.7 million (with each individual needing two doses).
Overall, the UK has secured access to 340 million doses across four separate types of vaccine – adenoviral vaccines, mRNA vaccines, inactivated whole virus vaccines and protein adjuvant vaccines (read more about how each works above).
These include:
- 60 million doses of the Novavax vaccine
- 30 million doses from Janssen
- 40 million doses of the Pfizer/BioNTech vaccine – the first agreement the firms signed with any government
- 60 million doses of a vaccine being developed by Valneva
- 60 million doses of protein adjuvant vaccine from GlaxoSmithKline (GSK) and Sanofi Pasteur
- 5 million doses of the jab on offer from Moderna in the US
- 100 million doses of the Oxford vaccine
Why so many? “What the government has done is order different vaccine classes,” explains Matthews. “It’s that simple.”
Read more:
- How do viruses jump from animals to humans?
- How do viruses make us ill?
- Who really invented vaccinations?
- How are seasonal flu vaccines made?
from... sciencefocus.com
Post a Comment