The boss of the pharmaceutical firm Astra Zeneca making the Oxford vaccine has said that having a three month gaps between jabs “is absolutely the right way to go”.
The independent scientific body, the JCVI, that advises the governments in the UK has recommeded a 12 week gap between first and second doses of the vaccines in the UK.
Other countries are still following a programme with a three-to-four week gap between doses and the UK’s decision to use a different regime has raised concerns.
The manufacturer of one of the other vaccines, the Pfizer vaccine, said that it only assessed its vaccine on a two-dose regimen where people were given the jab three weeks apart, and there was “no data to demonstrate that protection after the first dose is sustained after 21 days”.
However speaking to La Repubblica, the CEO of AstraZeneca Pascal Soriot endorsed the three-month plan with regard to the Oxford vaccine. He said the first dose alone gave 100% protection against severe disease and hospitalisation. He said the second dose was only needed to give longer-term protection.
“I think the UK one-dose strategy is absolutely the right way to go, at least for our vaccine,” he said.
“I cannot comment about the Pfizer vaccine, whose studies are for a three-week interval. In our case, the trial we’re talking about was conducted by Oxford University.
“We AZ are conducting the US trial, which we think is going to be ready very soon. Oxford University conducted the so-called Oxford trial in UK and Brazil, and we have data for patients who received the vaccine in one-month interval, 2 or 3 months interval.”
He added that taking the dose later would actually offer better long term protection.
He said: “First of all, we believe that the efficacy of one dose is sufficient: 100 percent protection against severe disease and hospitalisation, and 71-73% of efficacy overall. The second dose is needed for long term protection. But you get a better efficiency if you get the 2nd dose later than earlier.”
In the interview, he went on to explain the difficulty of manufacturing the vaccine at volume and why the company had told the EU it would not be able to deliver as much vaccine as it had hoped.
He said: “Essentially, we have cell cultures, big batches, 1000-litre or 2000-litre batches. We have cell cultures inside those batches and we inject them with the virus, the vaccine, if you will. Then those cells produce the vaccine, it’s a biotechnology protection. Now, some of those batches have very high yield and others have low yield.
“Particularly in Europe, we had one site with large capacity that experienced yield issues. So it’s essentially a question of when you scale up to the level we are scaling up to – something like this that’s never been done. We are scaling up to hundreds of millions, billions of doses of vaccines at a very high speed.
“A year ago, we didn’t have a vaccine. When you do that, you have glitches, you have scale-up problems. Therefore, the yield varies from one to three, by the factor of three. The best site we have produces three times more vaccine out of a batch than the lowest producing site.”
He also explained why deliveries to the UK had been higher, saying: “The facts are that we basically signed an agreement with the UK three months before we did have it with Europe.
“Now, part of this can be easily explained. When we entered the agreement with Oxford, they had already been working with the UK government on this. So they had a head start. We were able to quite quickly take the UK supply chain and improve it.
“We had to modify the formula in the process, because Oxford gave us a process that needed to be modified to enable manufacturing at scale. Just think about, we’ve done all of this in months.
“Usually, it takes years. We got a manufacturing process that Oxford gave us, which was producing a good vaccine, but not at an industrial scale. It was just able to produce quantities for clinical trials.
“So then we had to modify the process to turn it into a process that could manufacture billions of doses. At a cost that is reasonable and at a speed that is reasonable”.
You can use this calculator to find out when you are likely to be vaccinated in Wales.
Speaking on Monday, the health minister Vaughan Gething, said there had been a “sharp acceleration” as supplies of the vaccine had increased.
The vaccination effort in Wales has been given a massive boost by GPs over the last few days. In Powys, all 60 of its GPs are now offering the vaccine to patients. Mr Gething said Wales now has 329 GP practices offering vaccines and this will increase again this week.
You can read more about how Wales is delivering the vaccine here.