Vaccine may protect against the virus behind multiple sclerosis

The jab could ward off Epstein-Barr virus, which causes glandular fever and is increasingly being linked to multiple sclerosis, lymphoma and stomach cancer

By Alice Klein

Epstein-Barr virus causes glandular fever and is increasingly being linked to multiple sclerosis

BSIP SA/Alamy

A vaccine that wards off the common Epstein-Barr virus to potentially prevent glandular fever, multiple sclerosis (MS) and even some cancers has shown promise in mice, ferrets and monkeys. A human trial is expected to start in 2023.

Gary Nabel at ModeX Therapeutics in Natick, Massachusetts, and his colleagues developed a vaccine that exposes the body to two proteins that Epstein-Barr virus uses to invade cells, training the immune system to recognise the pathogen if exposed.

Initial experiments have shown that mice, ferrets and rhesus macaques developed antibodies against Epstein-Barr virus post-vaccination.

To better understand the jab’s potential in people, the researchers engineered mice with human-like immune systems. When exposed to Epstein-Barr virus, only 17 per cent of the mice became infected after receiving antibodies from other vaccinated rodents. In contrast, 100 per cent of the mice without antibodies became infected.

“It was a very promising result because we were able to basically block the virus infection almost entirely and stop it from causing even low-level infection,” says Nabel.

None of the mice that received the vaccine-induced antibodies developed lymphomas, cancers of the lymphatic system that are increasingly being linked to Epstein-Barr virus, compared with half of the unprotected rodents. The researchers didn’t look into any other Epstein-Barr-related conditions, such as stomach cancer.

More than 95 per cent of adults worldwide are infected with Epstein-Barr virus, a type of herpes that most commonly spreads via saliva. It is known to cause glandular fever, also called “mono”, and is associated with MS.

If the vaccine is shown to be safe and effective in people, it could be given to children to prevent Epstein-Barr-related conditions, says Nabel.

Moderna, the US company better known for its covid-19 vaccine, recently began a clinical trial for its own Epstein-Barr jab. Moderna’s vaccine differs from the ModeX candidate in that, similarly to its covid-19 jab, it uses mRNA to instruct cells to make several Epstein-Barr virus proteins, rather than administering them directly.

Julia Morahan at MS Australia says both vaccines look promising, but MS is a progressive disease and it will be several decades before we can gauge their potential.

“If we were able to give every child a vaccine, we would then have to wait a solid 25 years to see if they develop MS,” she says.

Journal reference: Science Translational Medicine, DOI: 10.1126/scitranslmed.abf3685