The UK has now secured access to more than 400 million doses of various coronavirus vaccines after reaching an agreement for a further 40 million doses of the Valneva jab, which is being manufactured in Scotland.
The Valneva vaccine is still being assessed in drug trials and will need to meet the necessary safety and effectiveness standards before receiving regulatory approval from the Medicines and Healthcare products Regulatory Agency (MHRA) and being rolled out.
The government has described the vaccine as "promising", and the additional 40 million doses adds to the 60 million already secured - an update on its efficacy is expected within the next three months.
It said the purchase was made to "ensure the UK has the best chance of securing access to successful vaccines as quickly as possible" and to give "future flexibility should we need to revaccinate any of the population".
If it is approved, 60 million doses could start to be delivered to the UK by the second half of 2021, with the remaining 40 million being delivered in 2022.
The deal will bolster long-term vaccine production in Scotland and brings the total UK vaccine portfolio to 407 million doses over the next two years.
The number of Covid-19 vaccine doses on order is enough to fully inoculate the UK's entire population twice - raising questions about when surplus jabs will be offered to countries having less success in their vaccination programmes.
The UK, which is leading the world with its vaccination programme, has approved three coronavirus vaccines, with the Pfizer/BioNTech and Oxford/AstraZeneca jabs already being rolled out, and the Moderna vaccine waiting in the wings.
The UK has ordered 40 million doses of Pfizer's vaccine, 100 million doses of the Oxford vaccine, and 17 million doses from Moderna.
A further four vaccines are either in clinical trials or awaiting MHRA approval; Novavax (60 million doses, Janssen (30 million doses),Valneva (60 million doses), GSK (60m doses).
Vaccines Minister Nadhim Zahawi said : "If approved, Valneva’s vaccine will not only help tackle Covid-19 here in the UK, but aid our mission to ensure there is a fair supply of vaccines across the globe.
"No one is safe till the whole world is safe."
The PM said the rollout “will only accelerate from here on”, after the daily number of jabs administered in the UK exceeded 500,000 for the first time.
Ministers are growing increasingly confident of hitting the target of vaccinating the 15 million most vulnerable people by mid-February after a record high of jabs on Saturday.
Official figures showed 598,390 first doses were administered across the UK, bringing the total number of people to have received a dose to 8,977,329.
Based on the latest figures, an average of 401,512 first doses of vaccine would be needed every day for the government’s February 15 target to be met.
Valneva’s site in Livingston, Scotland, will have the capacity to produce up to 250 million doses annually for shipment across the UK and around the world.
Different types of coronavirus vaccine:
Adenoviral vaccines: These are based on weakened versions of adenoviruses, which are a group of viruses that typically infect membranes of the eyes, respiratory tract, urinary tract, intestines and nervous system, and include the common cold.
mRNA vaccines: Traditional vaccines are made up of small or inactivated doses of the whole disease-causing organism, or the proteins that it produces, which are introduced into the body to provoke the immune system into mounting a response. But mRNA vaccines trick the body into producing some of the viral proteins itself.
Inactivated whole virus vaccines: Inactivated vaccines contain whole bacteria or viruses which have been killed, or small parts of bacteria or viruses, such as proteins or sugars, which cannot cause disease.
Protein adjuvant vaccines: An adjuvant is added to some vaccines to enhance the immune response, and has been shown to create a stronger and longer lasting immunity against infections than the vaccine alone.
The use of an adjuvant may reduce the amount of vaccine protein required per dose, which allows more vaccine doses to be produced.
The UK has placed orders for vaccines from:
BioNTech and Pfizer
Doses: 40 million – enough for 20 million people
The vaccine is being rolled out across the UK, having been approved for use on December 2 last year.
Oxford and AstraZeneca
Doses: 100 million – enough for 50 million people
The jab is being administered throughout the UK, after getting the green light from the MHRA on December 30.
Doses: 17 million – enough for 8.5 million people
The jab from the US biotech firm has been approved for use in the UK, but doses will not be available until the spring.
Type: Protein adjuvant.
Doses: Under the in-principle agreement, the UK has secured 60 million doses of the Novavax vaccine
The UK is providing infrastructure to Novavax in running a phase three clinical trial in the UK, and plans to manufacture its vaccine in the UK with Fujifilm Diosynth Biotechnologies.
Results from those trials show the vaccine offers 89% protection against Covid-19, but it still requires approval from the MHRA, which could take several weeks.
Doses: Some 30 million doses have been secured from Janssen, which is owned by Johnson & Johnson
Results from clinical studies show the jab is 66% effective overall at preventing moderate to severe Covid-19 28 days after vaccination.
Deliveries of the vaccine are expected in the second half of 2021, should it receive approval from the MHRA.
Type: Inactivated whole virus
Doses: Pending approval, the original order for 60 million is set for delivery in the second half of this year and now the option for a second batch of 40 million doses has been triggered. These have been earmarked for delivery in 2022.
Valneva’s site in Livingston, West Lothian, will manufacture the vaccine.
Clinical trials are ongoing, with the early-stage phase 1/2 study expected to read out within the next three months.
The jab is expected to be given as two doses.
GlaxoSmithKline (GSK) and Sanofi Pasteur
Type: Protein adjuvant
Doses: 60 million
Clinical trials for the vaccine are ongoing. Interim results of early phases of the trial showed an immune response comparable to patients who recovered from Covid-19 in adults aged 18 to 49 years, but a low immune response in older adults.
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