How big an impact will the approval of the Oxford/AstraZeneca vaccine have?
The Oxford/AstraZeneca vaccine is central to the government’s plans for ending social distancing in the UK and returning to some sort of normality. It has invested in seven different vaccines, but the biggest order is for 100m doses of the AstraZeneca jab, most of which will be manufactured in the UK. While the prime minister was jubilant that the UK was first in the world to approve the Pfizer/BioNTech vaccine, he is now able to claim a British triumph. More to the point is the ease of use of the AstraZeneca vaccine. Unlike Pfizer’s, it does not have to be kept in the long term at -70C. Pfizer’s vaccine can be stored in a fridge for five days, but AstraZeneca’s can be kept for months at fridge temperature, which is 2-8C and will be easy to take to care homes to administer to residents, the first priority group for vaccination.
How soon will I get my vaccine?
That depends on a few things, such as where you are in the priority list set out by the Joint Committee on Vaccination and Immunisation (JCVI), how many people can be recruited to carry out vaccination and how fast the vaccinating teams can work.
The first priority group is care home residents and the staff who look after them and second is the over-80s and NHS staff. Then it goes by decreasing age: the over-75s, over-70s and over-65s. Next are people of any age with underlying health conditions that put them at greater risk, then the over-60s, over-55s and over-50s.
This list makes up more than 25 million people. The health secretary, Matt Hancock, aspires to 2 million people a week being vaccinated, but that’s a big step up from the numbers so far. Even with the AstraZeneca vaccine being easier to deploy and local pharmacists and people with medical training who are not nurses joining vaccination teams, it will be a push. But if all went incredibly smoothly, most people in the first phase could theoretically have had their first shot by April.
What evidence is there to support a 12-week delay in getting the second dose?
The Medicines and Healthcare products Regulatory Agency (MHRA), which granted temporary emergency approval of the vaccines, has said in its authorisation that the second dose of Pfizer’s jab should be given at least three weeks after the first, and the AstraZeneca vaccine at least four weeks after. That is in line with what was done in the clinical trials. But the JCVI has gone further in the interest of getting some protection for as many people as possible, saying the second dose can be delayed up to 12 weeks after the first for both vaccines.
There is evidence from Oxford/AstraZeneca’s trials of greater efficacy among people who were given the second shot later – of 70% up to 12 weeks after the first. The JCVI says there is also evidence that is not in the public domain. Pfizer/BioNTech, however, have said in a statement that there is no evidence for the efficacy of a single shot of their vaccine beyond three weeks.
It seems clear that the JCVI recommendation is a piece of public health pragmatism. The more people who have some immunity, the less illness there is likely to be.
Is one shot enough?
No. It’s possible you may still get 70% protection beyond 12 weeks with the AstraZeneca vaccine – but the booster was always intended to be needed to lengthen the time that protection lasts.
Will everyone who needs a second shot be able to get it 12 weeks after the first dose?
That may depend on the arrival of batches of vaccine. Hopefully by the time most people need a second shot, there will be a smooth delivery system in place and no issues around supply. But at the moment, the stocks of the Pfizer/BioNTech vaccine are running short, especially in Europe where it is the only licensed vaccine. BioNTech has warned of a gap in deliveries because it cannot keep up with demand. Some regions of Germany, where the company is based, are having to pause their vaccination programmes until they get more stocks.
Can the vaccines be mixed and matched?
A trial is planned in the UK to assess whether people could be given one dose of the Pfizer jab and one of AstraZeneca’s – in whatever order. Scientists would say that you should run a trial and not do it without the evidence. However, the Green Book, which is the NHS handbook for staff on how to use vaccinations, has already been updated to say that if none of the first vaccine a person was given is available, they could be given a dose of the other. Although “every effort should be made to determine which vaccine the individual received and to complete with the same vaccine”. It says: “For individuals who started the schedule and who attend for vaccination at a site where the same vaccine is not available, or if the first product received is unknown, it is reasonable to offer one dose of the locally available product to complete the schedule.”