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What does Moderna’s Covid jab mean for the UK vaccine rollout? 

The vaccine that Dolly Parton helped fund is now being used as part of the UK’s coronavirus vaccine arsenal, but how crucial is the Moderna shot to the country’s rollout?

How does it work?

Like the Pfizer/BioNTech shot, the Moderna vaccine uses new mRNA technology that introduces genetic material containing the instructions to make the coronavirus’s spike protein into the body to elicit an immune response. Traditional vaccine approaches typically kickstart the immune system by exposing it to a killed or weakened part of the virus.

How effective is it?

In line with the Pfizer/BioNTech data, final results of Moderna’s vaccine against Covid-19 confirm it has 94% efficacy and nobody vaccinated in the 30,000-participant trial developed severe disease.

In the US clinical trial half the participants were given the jab, while the remainder got the placebo. Overall, 196 people fell ill. Thirty experienced severe disease and one person died, but none of these had the Moderna shot.

How does it fare against other authorised vaccines?

In the clinical trial setting, all three vaccines authorised in the UK were 100% effective in preventing hospitalisations and death.

The two mRNA vaccines are relatively similar in terms of preventing symptomatic Covid-19: the Pfizer shot has a 95% efficacy rate. In a pooled analysis of trials in the UK and Brazil, the Oxford/AstraZeneca vaccine had 70% efficacy overall, while in a US trial the vaccine demonstrated 76% efficacy.

However, that lower efficacy is arguably offset by its storage advantage – the Oxford jab can be kept at normal fridge temperatures, making it particularly useful in places that do not have the ultra-cold freezers operating at -70C to -80C that are necessary to store the Pfizer vaccine.

Moderna’s vaccine is relatively easy to store: it is stable for 30 days at normal fridge temperatures, but should it need to be stored for longer it can last for six months at -20C. Cost is another differentiator: last year Moderna said it was charging $32 (£24) to $37 a dose and defended its right to make a profit. The Oxford vaccine is not for profit, and is priced at £3 ($4) a dose.

Is it a gamechanger for the UK?

The UK has ordered more than 400m doses of seven different vaccines, including 100m from AstraZeneca, 40m from Pfizer, and 17m from Moderna. Given vaccine supply hiccups have already occurred and more will likely crop up, any additional shots are beneficial. “Any vaccine supply that we have to achieve our target of vaccinating all adults is to be welcomed,” said Paul Hunter, a professor in medicine at the University of East Anglia.

Are new jabs expected to come online soon?

Yes, among them are the Novavax jab, of which the UK has ordered 60m doses, and the Jansen (Johnson and Johnson) vaccine, of which the UK has ordered 30m doses.

Both have very promising clinical trial results but have not yet been approved by the UK’s Medicines and Healthcare products Regulatory Agency (MHRA).

The Novavax jab, which showed nearly 90% efficacy against symptomatic Covid in a UK trial, is already being made at a Fujifilm facility in Stockton-on-Tees, and will be bottled and packaged at GSK’s facility in Barnard Castle – the second time the location has shot to fame during the pandemic. This vaccine is contains coronavirus spike proteins that have been produced by moth cells infected with a genetically modified virus, and can be stored at temperatures between 2 and 8C – a feature that makes it easier to handle than jabs like the Pfizer-BioNtech vaccine that require extra-low temperatures.

The Jansen (Johnson and Johnson) vaccine has also had good clinical trial results, with an efficacy of 72% in a US trial and 66% in global trials, and can also be sorted and transported at temperatures between 2 and 8C. However, it has the added attraction of being a one-dose jab. Like the Oxford/AstraZeneca vaccine, this jab uses a modified cold virus to introduce the instructions for the spike protein into our cells – but whereas the Oxford/AstraZeneca vaccine uses a chimp adenovirus, the Jansen (Johnson and Johnson) vaccine uses a human cold virus.

Do people get a choice when it comes to which jab?

At present no, and the UK’s Joint Committee on Vaccination and Immunisation has not recommended that particular jabs are better suited to particular groups.

For jabs which require two doses (which is all of those currently approved by the MHRA), both doses will be of the same vaccine – although research is under way to explore whether the vaccines can be “mixed and matched”.

How reliant is the UK on the Oxford/AstraZeneca jab compared with other countries?

In short, the UK is more dependent on the Oxford/AstraZeneca jab than Europe or the US, although the jab is also crucial to the Covax initiative to ensure equitable global access to Covid vaccines.

The Oxford/AstraZeneca jab is a keystone of the UK’s vaccination programme – 100m doses of this vaccine have been ordered by the UK, that’s far more than the Pfizer/BioNTech and Moderna orders put together.

The Oxford/AstraZeneca jab has yet to be approved in the US: its vaccine programme is currently based on three Covid vaccines – Moderna, Pfizer/BioNTech and the Jansen (Johnson and Johnson) jabs.

In the EU, three vaccines have been approved: Moderna, Pfizer/BioNTech and the Oxford/AstraZeneca jab, with 160m doses of the former, 600m doses of the Pfizer/BioNTech vaccine, and up to 400m doses of the Oxford/AstraZeneca jab on order.

Supply problems have exacerbated the disparity. An acrimonious row between the EU and AstraZeneca has broken out with the latter saying it can only provide 100m doses to the EU in the first half of 2021, while the UK government signed a deal with the company that says it must deliver doses produced in the UK to Britain first.

Is the Oxford/AstraZeneca jab having any effect on getting cases down?

A key question for the Covid jabs is not only whether they prevent disease, hospitalisations and death, but whether they also prevent asymptomatic infections. If they do, then that could help to reduce the spread of the virus.

Recent data in the UK is promising, suggesting a single shot of the Pfizer/BioNTech jab can reduce the risk of an asymptomatic Covid infection by 75%, backing up earlier studies that suggested the reduce the risk of infection fell by 70% after one dose and 85% after the second shot.

But evidence suggests the AstraZeneca could also play an important role in preventing the spread of Covid, with one study suggesting a single dose of the vaccine could cut transmission by 67%. Indeed, the UK trial for this jab found two doses of the jab cut asymptomatic infections by 50%.

A further study, in care homes in England, found both jabs reduced the risk of infection by 62% at 35-48 days after the first dose.

Adam Finn, who advises UK health departments on immunisation and is a professor of paediatrics at the University of Bristol, said the picture is encouraging.

“Broadly the post-implementation data we have seen so far supports the idea that both vaccines significantly reduce both infection and onwards transmission – best estimates by about 40% in the family context,” he said.

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