What type of vaccine is this?
The jab is known as a messenger RNA (mRNA) vaccine.
Conventional vaccines are produced using weakened forms of the virus, but mRNAs use only the virus’s genetic code.
An mRNA vaccine is injected into the body where it enters cells and tells them to create antigens. These antigens are recognised by the immune system and prepare it to fight coronavirus.
What are the advantages of this type of vaccine?
No actual virus is needed to create an mRNA vaccine. This means the rate at which it can be produced is dramatically accelerated. As a result, mRNA vaccines have been hailed as potentially offering a rapid solution to new outbreaks of infectious diseases.
In theory, they can also be modified reasonably quickly if, for example, a virus develops mutations and begins to change. mRNA vaccines are also cheaper to produce than traditional vaccines, although both will play an important role in tackling Covid-19.
Where is the vaccine made?
Pfizer’s jab is being manufactured at the firm’s plant in Belgium, as well as separate sites in the US.
BioNTech — the other drug company involved in the vaccine — has two production facilities in Germany that are expected to start churning out doses in the New Year.
Is it safe?
All vaccines undergo rigorous testing and have oversight from experienced regulators.
Some believe mRNA vaccines are safer for the patient as they do not rely on any element of the virus being injected into the body. mRNA vaccines have been tried and tested in the lab and on animals before moving to human studies.
The human trials of mRNA vaccines – involving tens of thousands of people worldwide – have been going on since early 2020 to show whether they are safe and effective.
Pfizer will continue to collect safety and long-term outcomes data from participants for two years.
Don’t vaccines take a long time to produce?
In the past it has taken years, sometimes decades, to produce a vaccine.
Traditionally, vaccine development includes various processes, including design and development stages followed by clinical trials – which in themselves need approval before they even begin.
How has this come about so quickly?
In the trials for a Covid-19 vaccine, things look slightly different. A process which usually takes years has been condensed to months.
While the early design and development stages look similar, the clinical trial phases overlap, instead of taking place sequentially.
And pharmaceutical firms have begun manufacturing before final approval has been granted – taking on the risk that they may be forced to scrap their work.
The new way of working means that regulators around the world can start to look at scientific data earlier than they traditionally would do.
But won’t that mean that safety is compromised?
Even though some phases of the clinical trial process have run in parallel rather than one after another, the safety checks have still been the same as they would for any new medicine.
The Medicines and Healthcare products Regulatory Agency (MHRA) has adopted the phrase ‘safety is our watchword’.
Regulators have said they will ‘rigorously assess’ the data and evidence submitted on the vaccine’s safety, quality and effectiveness.
And, in most clinical trials, any safety issues are usually identified in the first two to three months – a period which has already lapsed for most vaccine front-runners.
How have regulators acted so quickly?
Regulators have been carrying out ‘rolling reviews’, which means that instead of going through reams of information at the conclusion of the trials, they have been given access to the data as the scientists work.
A rolling review of the vaccine data started several months ago.
This means regulators can start to look at scientific data earlier than they traditionally would do, which in turn means the approval process can be sped up. Regulators sometimes have thousands of pages of information to go over with a fine-tooth comb – which understandably takes time.
Once all the data available on the vaccine is submitted, MHRA experts will carefully and scientifically review the safety, quality and effectiveness data – how it protects people from Covid-19 and the level of protection it provides.
After this has been done, advice is sought from the Government’s independent advisory body, the Commission on Human Medicines (CHM).
So what data would the regulator have looked at?
The information provided to the MHRA will have included what the vaccine contains, how it works in the body, how well it works and its side-effects, and who it is meant to be used for.
This data must include the results of all animal studies and clinical trials in humans, manufacturing and quality controls, consistency in batch production, and testing of the final product specification.
The factories where the vaccines are made are also inspected before a licence can be granted to make sure that the product supplied will be of the same consistent high standard.