Mpox jabs might not protect against deadly new viral strain spreading rapidly, experts warn
THE mpox vaccine may fail against new, deadlier strain, experts warn.
They don't know how the jab, credited for helping put an end to the 2022 outbreak, will respond to the new version of the bug.
Professor Marion Koopmans, of the pandemic and disaster Centre at the Erasmus Medical Centre, said experts don't know how the new clade 1b mpox virus would react to current jabs.
"The honest answer is we do not know yet," she said.
The jab hasn't yet been tested against the more potent version of the bug that's spread across Africa and recently appeared in Europe and Asia.
The vaccine is a repurposed version of the jab used to prevent smallpox, a close relative of mpox.
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Experts thought it would work because the viruses are similar, a concept called cross-protection.
Since the vaccine was used during an active outbreak of mpox, it's tough to pinpoint its benefit, says Prof Marion.
During the 2022 outbreak, tens of thousands of Brits were jabbed against the virus.
Affected groups - which mostly included gay and bisexual men - were also encouraged to take practical steps to lower their risk, like cutting down on new sexual partners.
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"There is some evidence for clinical efficacy during the vaccinations were given during an evolving outbreak when there are also other things that people do that reduce transmission," Prof Marion said told a news conference.
"It's not so easy to say is this full-vaccine protection.
"The hope is that for clade 1b there would also be sufficient cross-protection, but that's an area with an urgent study need," MailOnline reported from the event.
Professor Dimie Ogoina, an infectious disease expert at Niger Delta University, also pointed out that we still don’t know how effective the current mpox vaccines are.
"One cannot (guarantee) to say the effectiveness was based fully on the vaccine alone.
"Some studies have shown behavioural change was responsible for the decline in mpox cases in parts of Europe and America, while vaccines also helped," he said.
But Professor Placide Mbala Kingebeni, an epidemiologist at the National Institute of Biomedical Research in the Democratic Republic of the Congo (DCR), the nation hit hardest by the ongoing outbreak, said jabs remained the best defence we have.
The new strain of mpox, formerly called monkeypox, is far deadlier than the mild clade 2 strain which spread to over a dozen countries, including the UK in 2022.
It is thought clade 1b mpox, kills about five per cent of adults and 10 per cent of children it infects.
The virus is transmitted through close contact, such as sex, or skin-to-skin contact with another person.
Clade 1b has swept through central Africa having already killed at least 500 people and infected 13,700, according to African Health authorities.
In just the past few weeks cases of the new strain have been detected in Sweden and Thailand.
While no cases have yet been confirmed in the UK experts suspect the new variant is already in Britain.
Due to how long it takes for symptoms to emerge, they believe we could see cases within the next two weeks.
However, Europe is unlikely to see as many deaths as central Africa due to better access to quality healthcare, they said.
What is the UK doing?
The NHS is already on high alert for UK cases of the strain.
Rapid testing is being made available and GPs and hospitals have been told to isolate those with symptoms of the mutant bug.
The Government is said to have enough vaccines and treatments to deal with an outbreak.
The NHS offers the smallpox (MVA) vaccine to people who are most likely to be exposed to mpox.
This includes healthcare workers looking after patients with suspected or confirmed mpox, men who sleep with men and people who have been in close contact with a suspected case.
You can get vaccinated before or after exposure.
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Mpox typically causes characteristic an itchy and sometimes painful rash on the face, palms of the hands and soles of the feet.
In a small number of cases, it leads to complications like brain swelling encephalitis, inflammation of the heart (myocarditis), lung infection (pneumonia), eye issues and death.
Should we be worried?
Dr Jonas Albarnaz, a research fellow specialising in pox viruses at The Pirbright Institute, said:
"This news of a case of clade 1 mpox in Sweden is concerning for two main reasons.
"First, this is the first clade 1 mpox virus case outside Africa. This indicates that the extent of the international spread of clade 1 outbreak in DRC might be larger than we knew yesterday.
"And second, clade 1 mpox virus is associated with a more severe disease and higher mortality rates than the clade 2 virus responsible for the international mpox outbreak in 2022.
"This is hard to predict whether we will see further cases of clade 1 mpox outside of Africa, but this case in Sweden is a warning call for public health authorities to be vigilant and implement robust surveillance and contact-tracing strategies to detect possible new cases early on.
"It’s also critical to determine what is the link between this clade 1 mpox virus detected in Sweden and the ongoing outbreak in DRC."