09-07-2025
Moderna developing first mRNA vaccine for Marburg
The pharmaceutical giant Moderna is developing the first mRNA vaccine to protect against Marburg, a close but even deadlier cousin of Ebola.
The haemorrhagic fever, which transmits to humans via fruit bats before rapidly spreading person to person, has caused several lethal outbreaks in sub-Saharan Africa – most recently killing 10 people in Tanzania earlier this year.
While Marburg kills more than half of those it infects, there are currently no licenced vaccines or treatments available to tackle it, posing a significant challenge to outbreak response.
Researchers at the University of Texas and Moderna say a new vaccine developed using mRNA technology (used during the pandemic to quickly deliver Covid vaccines) provided full protection against Marburg in a pre-clinical trial carried out on rodents.
The new immunisation produced 'strong neutralising antibodies' and 'importantly, no virus was detectable in the blood of vaccinated animals after exposure – suggesting sterilising immunity,' the study said.
'The fact that we achieved complete protection in all vaccinated animals is a major leap,' said Dr Alexander Bukreyev, an author of the study.
'Moderna's mRNA platform is proving to be very potent when targeting highly lethal pathogens,' added Dr Andrea Carfi, a researcher at the pharmaceutical company.
The jabs will still need to go through rigorous human trials before being licenced for use.
Marburg disease belongs to the Filovirus family, a group of viruses which includes Ebola. It is naturally carried by fruit bats, and can 'jump' to humans via the animals' bites or contact with the animals' urine or saliva.
Once a person is infected, the virus tends to spread rapidly, mainly through contact with the bodily fluids of a sickened person.
Symptoms include high fever, severe headache, muscle pains, diarrhoea, vomiting, and bleeding under the skin and from the eyes.
The virus was first recognised after simultaneous outbreaks occurred in laboratories in Marburg, Frankfurt, and Belgrade, in 1967.
A group of at least 30 lab workers all came into contact with the bodily fluids of a batch of imported African green monkeys from Uganda and became severely unwell.
Seven of the lab workers subsequently died, before the virus's origins were traced back to the monkeys.
Since, outbreaks have occurred sporadically and have all occurred in sub-Saharan Africa in countries including Angola, Equatorial Guinea, Ghana, and Uganda.
However, the frequency of outbreaks has been increasing in recent years with at least one cluster of cases occurring every year since 2021.
Scientists suggest that part of the reason for the uptick in cases is related to human encroachment on previously undisturbed habitats which gives more of an opportunity for the virus to spillover from animals to humans.
In January of this year, 10 people in Tanzania were reported to be infected with Marburg virus – all of which died.
Biharamulo district, the area in which the virus spread, is home to several large gold mines and it was suspected that the index case was infected by a bat while working in a mine.
Rwanda also experienced an outbreak of Marburg in September last year – the first ever to be reported in the country – in which 16 people died, mostly healthcare workers in the capital city, Kigali.
US health secretary Robert F Kennedy Jr quietly announced last month that the Department of Health and Human Services would develop two new vaccines – one for use against Marburg virus and one against Sudan virus, a type of Ebola.
The two jabs are in the early stages of development but, unlike Moderna's vaccine, they do not use mRNA technology – which has come under fire from Mr Kennedy and his vaccine sceptic allies since the Covid-19 pandemic.
