How to vaccinate 70 million people at speed

“Do we now say with confidence that life should be returning to normal by spring?,” Sarah Montague asked her World At One guest tentatively. It was the 10th of November - the day that Pfizer announced that it was confident that it had successfully developed a Covid-19 vaccine that is effective in upwards of 90 per cent of cases.

Then, to her visible surprise, Prof Sir John Bell, Regius Professor of Medicine at the University of Oxford and one of the world’s most eminent immunologists, answered with a surprising lack of hesitation: “Yes… yes… yes,” he said.

The vaccine breakthrough does suggest that the nightmare may soon be over, but will it really be over as quickly as Sir John suggests?

Since that broadcast, the good news has continued, with Moderna also announcing a similarly effective vaccine. Now the question is less one of science and more one of logistics. Just how difficult is it going to be to vaccinate all 70 million people in Britain?

“The biggest challenge that's currently on the horizon is having to do an ultra-low cold-chain distribution” says Professor Philip Greening, a logistics expert at Heriot-Watt University in Edinburgh. A cold chain is what it sounds like: a supply chain that ensures that the products being transported are consistently refrigerated until they reach their end destination.

Though trials are still ongoing, it appears that the Pfizer vaccine may require a cold chain that keeps temperatures as low as minus 80°C. According to Greening, such freezers do exist and are often found in hospitals and research institutions, but many more would be required for distributing the vaccine.

“The challenge is the scale,” says Greening. “Do we have the technology? Yes, we do. Do we have a way of scaling with that technology? Probably not yet.”

How quickly could Britain establish the infrastructure required? Prof Amar Ramudhin, a supply chain expert at the University of Hull, points to a previous epidemic as a guide.

“The Ebola vaccine had to be stored at minus 60°C and was distributed to mostly African countries,” he explains. “Nobody really talks about it, but it was done and it was a success.”

A week after Pfizer announced their breakthrough, an announcement from Moderna carried potentially even better news. Its vaccine does not require such low temperatures. In fact, it can be stored at just minus 20°C. This difference is significant, as Britain and the rest of the world has both significantly more freezer capacity at this temperature and a supply chain that is more than capable of maintaining the required temperature, as evidenced by the freezer section in every supermarket in Britain.

While Moderna’s vaccine sounds, at least on the surface, like a better candidate for mass vaccination, it currently appears that the vaccine will take longer to arrive. While the first doses of the Pfizer vaccine could conceivably be delivered by the end of the year, Moderna’s will not be available until the spring.

In any case, multiple different vaccines will eventually be needed. So far, the UK government has ordered 40 million doses from Pfizer and five million from Moderna, along with millions more of the other promising vaccine candidates. Whichever vaccines are eventually proven to be the most effective or viable, each will present a challenge for policy makers, as each will shape how the roll-out is designed.

“The characteristics of the vaccine will impact the possible vaccination strategies”, says Greening. He points to how the storage requirements for the vaccine will inevitably change how the vaccine is administered.

For example, if the vaccines do require specialist freezers that only have limited availability, it may be impossible to distribute widely across the country and the programme will instead have to be built around having all 70m people in Britain travel to a limited number of sites, such as hospitals. This would carry its own logistical challenge as people, including the elderly and vulnerable, may need to travel from some distance away.

As things stand, the NHS appears to be focusing on using local GP surgeries as the primary mechanism for getting people vaccinated. It has sent out a notice to GPs urging them to ready themselves to switch their operations to deliver the vaccine. Even if this more distributed approach is possible - perhaps with vaccines stored in standard freezers - this presents arguably an even more complex logistical challenge.

“The biggest issue in a cold chain is where you have touch points,” says Ramudhin, referring to the points in a supply chain where manual intervention is required to get the goods on to the next part of their journey. Sending the vaccine to hundreds or even thousands of GP practices would mean many more touchpoints than if it were just being sent to a few dozen hospitals.

“As long as it's in a storage facility or in transit at a control temperature, the chances of something happening is less, but each time you have to transfer it, and you have to break the pallets into smaller [quantities] and humans are involved, that's when you have the greatest risk,” he explains.

The logistics challenge doesn’t end with shipping the vaccine from one place to another. There are many further layers of complexity in terms of delivery, too.

“It could be the most trivial of things that stops us vaccinating people at the rate that we want to,” says Greening, who points to issues similar to what we saw at the start of the pandemic around the supply of PPE equipment. Administering a vaccine may be a simple procedure, but it requires disposable medical equipment, such as syringes and gloves, to do it safely.

One other problem is that once a vaccine does arrive, every country in the world will be scrambling to obtain additional PPE equipment.

“Managing the inventory becomes tricky, because our starting point is zero demand and then overnight it'll go to very high levels of demand,” says Greening. “Replenishment of inventory, wherever it's being consumed, is almost bound to be not straightforward.

There are, however, some causes for optimism. One is in terms of people. Ramudhin expects that the likes of DHL and Fedex, which have partnered with the drug companies, will have no problem raising the army of people required to get the vaccines out as quickly as they can be produced.

“They're used to huge peaks. Think about Christmas. Think about Black Friday,” he says. “They're used to being able to scale up their workforce and do rapid training for different things. I don't think that would be too much of an issue,” he says.

The other good news is about another kind of scale. “The thing to remember with the vaccine is it's very small,” says Greening. “The benefit is that you don't necessarily need many vehicles to deliver lots of vaccines.”

With a single lorry able to carry thousands of doses in one go, it makes the logistics challenge drastically easier. However, this also carries with it a potential challenge.

“You can get a lot of vaccines into one vehicle and if something happens to that vehicle that causes it to go out of temperature, or that you're not sure that it's been in temperature, then that can present quite a significant hiccup in the supply of vaccines.”

How can planners mitigate these sorts of risks? “The whole distribution system will be sensitive to small changes in different places,” says Greening. “You need to have the feedback in the system working well, so that you can accommodate any changes in demand or any needs from the system quickly.”

The logistics challenge is not to be underestimated. Just how confident are the supply chain experts that Britain can ultimately vaccinate all 70m people in a timely fashion? Is Prof. Sir John Bell right that we could see life begin to return to normal early next year?

“I think Spring is a little bit optimistic,” says Ramudhin, pointing to the fact that the 40 million doses of the Pfizer vaccine that the UK has secured translates to 20 million people, because each recipient needs to receive the vaccine twice - and that it would be typical for 5-10 per cent of doses to go to waste because of problems with the logistics of administering the programme, whether that be a lorry breaking down on the M1 or people failing to turn up for appointments.

“I don't think everybody will be vaccinated by Spring, but within the next year I'm assuming things will get much better,” he concludes.

“The clue is in the words,” says Greening of Sir John’s prediction, noting Sir John’s emphasis: “Will we ‘start’ to get back to normal in Spring? I agree with him.

“I think once we've worked out how to ramp up the vaccination programme, and we've got the manufacturing process producing the vaccines, people will be quite pleasantly surprised how quickly we get this done.”