Back to normal by Spring? Everything we know about the Pfizer Covid-19 vaccine
The pharmaceutical giant Pfizer, working with German biotech company BioNTech, released an interim analysis on 9 November suggesting their vaccine is more than 90 per cent effective in preventing Covid-19.
With 40 million doses earmarked for the UK (10 million doses by the end of the year, with a further 30 million doses already ordered), the breakthrough could be instrumental in helping get Britain back to normal by Spring.
There are, however, logistical challenges, as the vaccine needs to be stored in ultra-cold storage at or below -80C.
Here is a round up of everything you need to know about the vaccine:
What is the vaccine?
The jab is known as a messenger RNA (mRNA) vaccine.
Traditional vaccines work by injecting a deactivated or weakened form of the pathogen into the body in order to train it to recognise and defeat the active virus.
However, both the Oxford and Pfizer vaccines seek to introduce into the body a genetic sequence that prompts human cells to churn out parts of the Sars-Cov-2 virus, so the body can learn to deal with it that way.
No actual virus is needed to create an mRNA vaccine. This means the rate at which the vaccine 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.
mRNA vaccines are also cheaper to produce than traditional vaccines.
They can also be modified reasonably quickly if, for example, a virus develops mutations and begins to change.
On 8 November it was reported that Jonathan Van Tam, the deputy chief medical officer, has told doctors, nurses and GPs to take "immediate action" against a new strain of the virus found in minks that is feared to be resistant to vaccines.
How does the Pfizer BioNTech vaccine work
Will we get it in the UK?
The UK has secured 40 million doses of the Pfizer/BioNTech vaccine – the first agreement the firms signed with any government.
It is thought people will need two doses, meaning not enough shots have been secured for the entire UK population.
However, it is likely other vaccines will announce results from their clinical trials shortly.
Pfizer plans to apply to the US regulator the Food and Drug Administration (FDA) for emergency approval to use the vaccine by the end of November.
Based on current projections the pharmaceutical giant expect to produce globally up to 50 million vaccine doses in 2020 and up to 1.3 billion doses in 2021.
But Dr Michael Head, senior research fellow in global health, University of Southampton, said that if the vaccine is approved for use by regulators then there could be difficulties posed by logistics and distribution due to the temperature that the vaccine needs to be stored at.
"If this Pfizer vaccine candidate is licensed, there will be difficulties around logistics and distribution," Dr Head added.
"It has been reported that the vaccine requires storage at -70 degrees centigrade and that is not necessarily routinely available in most health centres even in the UK, let alone globally."
What stage is it at?
Vaccine: The study
The Phase 3 clinical trial began on July 27 and has enrolled 43,538 participants to date, 38,955 of whom have received a second dose of the vaccine candidate as of November 8, 2020.
On the 9 November Pfizer announced that the Phase 3 trial indicated a vaccine efficacy rate above 90 per cent, at 7 days after the second dose. This means that protection is achieved 28 days after the initiation of the vaccination, which consists of a 2-dose schedule.
The vaccine has been tested on people in six countries and no safety concerns have been raised.
The analysis was carried out after 94 confirmed cases of Covid-19 were found among those taking part in the trial.
Approximately 42 per cent of global participants and 30 per cent of U.S. participants have racially and ethnically diverse backgrounds.
Pfizer will continue to collect safety and long-term outcomes data from participants for two years.
What does this mean?
Dr Michael Head, senior research fellow in global health, University of Southampton, said the results appear "excellent" but he urged caution.
"This cautiously sounds like an excellent result from the phase three trials, but we should remain a little cautious," he said.
"The provisional findings are made available in a press release and the study is ongoing. However, if the final results show an effectiveness of anywhere near 90% with response in elderly and ethnic minority populations, that is an excellent result for a first generation vaccine.
"This has been seen before – the rapidly-produced Ebola vaccine generated very high levels of effectiveness and exceeded all expectations. Equally, billions of dollars and numerous clinical trials have struggled to produce any form of vaccination against HIV. Science can be unpredictable."
But Sir John Bell, regius professor of medicine at Oxford University and a member of the Government’s vaccine taskforce, said that other vaccines were now likely to become available in the near future.
"I am really delighted with this result – it shows that you can make a vaccine against this little critter. Ninety percent is an amazing level of efficacy," he told BBC Radio 4’s The World at One.
"It rolls the pitch for other vaccines because I can’t see any reason now why we shouldn’t have a handful of good vaccines."
Asked if people could look forward to a return to normal life by the spring, Sir John replied: "Yes, yes, yes, yes. I am probably the first guy to say that but I will say that with some confidence."
Is the vaccine safe?
The vaccine is still early the stages, having only been studied for a matter of months.
We do not yet know if it is able to prevent severe cases of Covid-19, how long it will protect against infection or if it prevents people from carrying the virus without symptoms.
According to previous data, it does cause side effects, including aches and fevers.
William Gruber, Pfizer’s senior vice president of vaccine clinical research and development, has told Stat News that he believed the side effect profile was comparable to standard adult vaccines, but probably worse than Pfizer’s pneumonia vaccine, Prevnar, or a flu shot.
The results have not been peer-reviewed by outside scientists or published in a medical journal, and even Pfizer and BioNTech have not been given further details about how the vaccine performed by the independent monitors overseeing the study.
Coronavirus podcast – When will we be vaccinated?
Who will be vaccinated first?
The Joint Committee on Vaccination and Immunisation (JCVI) has examined data on who suffers the worst outcomes from coronavirus and who is at highest risk of death.
Its interim guidance says the order of priority should be:
- 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.