An animal study that was published in the journal Cell on Wednesday shows that an experimental Moderna mRNA vaccine for mpox has proven to be more effective than existing vaccinations in lowering the symptoms and duration of the illness.
It coincides with a worldwide emergency proclaimed due to an outbreak of the disease in Africa, which is partially caused by a novel form that surfaced in the Democratic Republic of the Congo.
According to AFP, virologist and senior author Jay Hooper of the US Army Medical Research Institute for Infectious Diseases said that scientists were looking into mRNA technology in an effort to identify a “sweet spot”—an mpox vaccine that is exceptionally safe and effective.
Immunizations against mpox, also called monkeypox, were first created to fight smallpox, which has since been eradicated.
The JYNNEOS vaccine that is now licensed uses a “live attenuated” virus, which has been weakened to the point where it cannot infect people.
In comparison to the earlier ACAM2000 vaccine, which was potentially contagious, this attenuation further reduces the vaccination’s effectiveness in providing protection.
The host’s immune system is taught to identify four essential viral antigens by the mRNA vaccine, on the other hand, as these antigens are necessary for the virus to bind to cells.
Moderna’s extremely safe and efficacious coronavirus vaccine makes use of the same mRNA technology.
Six macaques in the study received the mRNA vaccine, while the remaining six received a vaccination comparable to the one that is currently licensed.
All 12 of the vaccinated macaques were exposed to a deadly type of mpox eight weeks following their first injection. Six uninfected macaques in a third group were also exposed to the virus.
Over a four-week period, researchers collected blood samples from the animals to evaluate their immune responses and kept an eye on their health.
All of the vaccinated animals—regardless of the type of vaccine—survived as expected, while five of the six unvaccinated animals perished.
AFP was informed by co-senior author Galit Alter, a virologist and immunologist at Moderna, “that what we saw was quite surprising and exciting if we focus specifically on the outcomes with the mRNA vaccine.”
Compared to animals given the live attenuated vaccination, those given the mRNA vaccine showed significantly fewer lesions and reduced weight loss.
The control group experienced an average of 1,448 lesions, the older vaccine group a maximum of 607 lesions, and the mRNA-vaccinated group a maximum of 54 lesions.
In addition, compared to the MVA vaccination, the mRNA vaccine reduced the number of days that the mice displayed lesions by over 10. Additionally, it produced reduced viral loads in throat and blood swabs, indicating that it might be more successful in limiting transmission.
Serum from the mRNA-vaccinated macaques was tested against other Orthopox family viruses, and it successfully neutralized vaccinia, cowpox, rabbitpox, camelpox, and ectromelia virus, according to first author Alec Freyn of Moderna, who spoke with AFP.
In order to evaluate the vaccine candidate’s safety and immunological response, an early-stage human clinical trial called mRNA-1769 is currently taking place in the UK.
