Brits trial ‘Covid-style’ MPOX jab said to reduce symptoms by 90 per cent and slow spread

Research shows a new MPOX jab, which uses the same technology as the Covid vaccines and is currently being tested on Britons, reduces symptoms and reduces transmission of the deadly virus.

The new vaccine, developed by pharmaceutical company Moderna, has been called ‘mRNA-1769’ and was tested directly against a deadly variant of mpox, in a trial using macaque monkeys, a type of primate.

It was also compared directly to a vaccine currently used to protect people against the virus, which is designed to combat smallpox, a virus closely related to mpox.

Experts found that the mRNA shot reduced the number of mpox lesions, a classic symptom of the disease, in the monkeys by 96 percent and also reduced the number of sick days by 10.

Blood and saliva smears from the macaques also showed that the viral load was lower in the animals that had received the mRNA shot.

The authors suggested that this could mean it is more effective at reducing the chance of the monkeys passing mpox on to other animals.

The findings come a week after experts warned that currently available vaccines may not work against a new MPOX strain that is sweeping through Central Africa and has now reached Europe and Asia.

This new strain, called clade 1b, is much deadlier than the clade 2 strain that spread globally in 2022, primarily affecting gay and bisexual men.

While the Moderna study didn’t test their vaccine on clade 1b, they did test it on clade 1a, which is closely related to clade 2 and also more deadly.

In the study, the results of which were published in the journal Cellscientists tested three different groups of six macaques.

One group received the new Moderna shot, the other the classic smallpox shot, the smallpox vaccination, and the last group was not vaccinated and served as a control.

Vaccinated monkeys were given the lethal mpox strain four weeks after their dose, before being exposed.

Experts then monitored the animals for four weeks, conducting regular blood tests to examine their immune response.

At the end of the trial, all twelve vaccinated monkeys had survived, while five of the six unvaccinated macaques died.

While both shots reduced the severity of the mpox infection, scientists found that the mRNA shot appeared to be much more effective.

For example, unvaccinated monkeys with mpox developed a maximum of 1,448 lesions, while monkeys with the standard shot developed only 607. That is a decrease of almost 60 percent.

However, animals that received the mRNA injection developed a maximum of 54 lesions, a difference of 96 percent.

Monkeys that received the mRNA shot were also sick for a shorter period of time, with lesions disappearing 10 days faster than in monkeys that received the older shot.

This pattern was repeated in other measures of disease severity. For example, monkeys given the mRNA shot lost less weight during their illness than monkeys given the traditional vaccine.

The Moderna team also said the results from the blood and throat swabs showed lower levels of virus in the bodies of the monkeys that had received the mRNA shot.

They argued that this ‘could be more effective in reducing transmission’.

Alec Freyn, a virologist at Moderna and co-author of the study, said the experiment was the first to test an MPOX vaccine still in development against current vaccination options.

“When we tested those vaccines directly in primates, we saw a better response to the mRNA vaccine. Not only was there protection in survival, but there was also less injury, shorter duration of illness, and less shedding of the virus in the blood and respiratory tract,” he said.

Co-author Galit Alter, a virologist and immunologist at Moderna, said the mRNA technology behind the shot, the same technology used to produce the company’s Covid shots, is responsible for the improved protection.

“With the mRNA vaccine, we can select pieces of the virus that can produce the most powerful and effective immune response,” she said.

‘If you do that, you’re not distracted by the whole virus. You can then focus on the parts of the virus that offer you protection.’

In the case of mRNA-1769, the shot targets four parts of the virus that are crucial for attaching to and entering human cells.

Another part of the research involved testing antibodies produced by the monkeys’ immune systems that are designed to fight pathogens such as mpox and other viruses.

Mr Freyn said these results were positive.

“It not only neutralized mpox, but also vaccinia, cowpox, rabbitpox, camelpox and ectromelia virus. We believe this vaccine can protect against other threats that may arise in the future.”

mRNA-1769 is currently being tested among 350 Britons in England aged 18 to 49.

This trial is designed to measure the safety and immune response of different doses of the vaccine in humans.

Unlike the recently published study, it does not involve exposing people to potentially deadly mpox. It is due to be completed in June next year.

While the Moderna authors referenced the current outbreak in their study, they did not speculate about the potential effectiveness of their new shot in this context.

The new variant of mpox, previously called monkeypox, is much deadlier than the mild strain that spread to more than a dozen countries, including the United Kingdom, in 2022.

About one in twenty adults who contract it die from the disease. In children, however, the death rate is one in ten.

By comparison, clade 2 killed only about one in every 500 people who became infected.

The virus is mainly spread through skin-to-skin contact, for example through sex, or through direct care, for example from mother to child.

Clade 1b is sweeping through Central Africa, claiming hundreds of lives since the outbreak began.

In recent weeks, cases of the new variant have been discovered in Sweden and Thailand, meaning the virus has now reached both Europe and Asia.

Although no cases have been confirmed in the UK, experts suspect the new variant is already in Britain, as it can take more than two weeks for symptoms such as the classic skin lesions to develop.

However, experts say that death rates for clade 1b in Central Africa are likely unmatched in developed countries, due to greater access to higher-quality health care.

Britain’s Health Security Agency has warned it is “already planning” for cases of the new variant in the UK.

Mpox is usually ccauses characteristic lumpy lesions, as well as fever, aches and fatigue.

In a small number of cases it can spread to the blood and lungs, but also to other parts of the body, such as the brain, where it can become life-threatening.