Just one week after Pfizer released positive early results of their vaccine trials, the American biotech company Moderna has revealed that its own candidate appears to be even more effective in preventing disease among those infected with Covid-19.
It marks another important step forward in the fight against the virus, paving the way for the emergence and development of more coronavirus vaccines.
So, what do we know about this latest candidate?
According to early data released by Moderna, the vaccine is 94.5 per cent effective in preventing disease among infected individuals and appears to be safe. Vaccination requires two jabs, administered 28 days apart.
This efficacy rate is based on independent analysis of 95 infections that have been recorded among the firm’s ongoing phase-three trial. Covid-19 was observed in 90 volunteers from the placebo group and five participants who had received the vaccine.
A total of 30,000 people have been enrolled in the study, including the elderly, participants from diverse communities, and individuals with underlying health conditions.
“We will need much more data and a full report or publication to see if the benefit is consistent across all groups, notably the elderly, but this is definitely encouraging progress,” said Stephen Evans, professor of pharmacoepidemiology at the London School of Hygiene & Tropical Medicine.
What are the side effects?
Independent analysis of the Moderna vaccine did not find any significant safety concerns. Adverse reactions to the jab were considered mild or moderate in severity, and included fatigue, pain around the site of injection or headaches.
What don’t we know?
As with Pfizer’s candidate, it’s hard to say at this stage how long immunity will last for.
Some experts have predicted that the response triggered by these mRNA jabs could be stronger and longer-lasting than the immunological memory acquired through natural infection. Others have said that booster jabs will likely be needed to keep “topping up” our immune systems.
We also don’t know what sort of immunological activity it generates in different demographic groups. Scientists and governments will be particularly keen to see the vaccine’s effectiveness among those aged 60 and above, along with other at-risk groups.
Similarly, is it not known whether the Moderna vaccine offers protection against infection and can therefore halt the transmission of Covid-19. Only once enough people have been vaccinated will we have a better idea of whether the spread of the virus has been slowed within the community.
Nor can we be sure of the vaccine’s final efficacy rate. The phase-three study is still ongoing, and Moderna has said it will conduct a full review of all its data once 151 infections have been recorded among the phase three trial’s participants.
This figure will give the regulators a clearer indication of the vaccine’s effectiveness, but there’s a chance it could drop.
What comes next – and when will it be available?
Moderna said it intends to apply for an Emergency Use Authorisation with US regulators “in the coming weeks”. Assessment of the vaccine’s suitability will be based on the final analysis of 151 recorded cases, the biotech company added.
The European Medicines Agency said separately on Monday that it had begun a rolling review of Moderna’s trial data, while the UK’s Medicines and Healthcare products Regulatory Agency is similarly assessing the vaccine.
Moderna has said it expects to provide the US government, which helped to fund research into the vaccine, with 20 million doses by the end of the year. It intends to manufacture between 500 million and 1 billion doses globally throughout 2021.
Does the UK have access to any of these doses?
At this stage, no. But No 10 says it is “in advanced discussions” with Moderna to secure a deal for the provision of doses.
It is understood that Moderna does not currently have an advanced European supply chain in place, but is currently planning to “scale up” its capacity to deliver to the continent. It is not thought likely that doses would become available in the UK before next spring.
No 10 has already agreed deals for six different vaccine candidates, and has access to 350 million doses to date – 40 million of which will be provided by Pfizer. “We have prioritised agreements with developers who offer different kinds of vaccine, can deliver early supplies to the UK and have advanced supply chains in place,” Boris Johnson’s official spokesperson said.
What challenges can we expect in the global rollout?
One of the key advantages to the Moderna vaccine is that it doesn’t need to be stored at -70C.
The candidate, named mRNA-1273, can be stored at fridge temperature for 30 days, or -20C for up to six months. This will make it much more accessible to lower- and middle-income nations, many of which may be precluded from distributing the Pfizer jab on account of the infrastructure needed to store and distribute it among communities.
Juan Andres, chief technical operations and quality officer at Moderna, said the technology that had gone into the vaccine “would enable simpler distribution and more flexibility to facilitate wider-scale vaccination in the United States and other parts of the world”.
Dr Richard Hatchett, chief executive of the Coalition for Epidemic Preparedness Innovations, said: “The fact that the vaccine shows stability when stored in a normal refrigerator for up to 30 days is also terrific news and will allow the vaccine to be distributed broadly.”
However, the expected manufacturing costs of the Moderna vaccine will be higher than those of its Pfizer rival because the Moderna candidate uses a greater amount of mRNA per dose. This means that Pfizer will be able to manufacture more doses using the same scale of production as Moderna – once the two candidates are approved.
However, Dr Zoltan Kis, a research associate at Imperial College London’s Future Vaccine Manufacturing Hub, believes the ability to store mRNA-1273 at higher temperatures will allow doses to “be distributed substantially easier and at lower costs”.
What are the advantages of the technology used by the Moderna vaccine?
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.
In theory, they can also be modified reasonably quickly if, for example, a virus develops mutations and begins to change.
mRNA vaccines are also cheaper to produce than traditional vaccines, but both will play an important role in tackling Covid-19.
Addressing Moderna’s announcement, Peter Openshaw, professor of experimental medicine at Imperial College London, said: “This is a loud vote of confidence in RNA vaccine technology, which seems to be safe, acceptable and effective in studies of 70,000 people. These results set a high bar for the other vaccines in the pipeline.”
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