A new mRNA vaccine candidate for monkeypox (mpox), developed by Moderna, proved 100 times better than any of the licensed vaccines at reducing disease symptoms and duration — in an animal study made available on the Cell Press Sneak Peek press-sharing site.
Addressing the Limitations of Current Mpox Vaccines
The licensed JYNNEOS vaccine for mpox (also from POXVIRUS) uses a live attenuated virus that was based on the design features of the historical smallpox vaccines. That the virus has been attenuated to such an extent that it cannot cause disease in humans. But this dilution likewise restricts the vaccine’s benefits by it compared to your previous potentially contagious vaccine, ACAM2000.
By contrast, the Modern mRNA vaccine provides genetic instructions to teach the host’s immune system to target four critical viral antigens that are necessary for viral attachment to cells. The ‘sweet spot’ — an mpox vaccine that is very safe, yet very effective The new method proposed to the U.S.
Impressive Results in Animal Studies
The animal study, run by researchers at the U.S. Army Medical Research Institute of Infectious Diseases and Moderna, vaccinated six macaques with the mRNA vaccine and another set of six with a comparator to a licensed vaccine dose. Two months after the first vaccination, all 12 of the vaccinated monkeys in each of the two groups were given a lethal strain of mpox, along with another six unvaccinated monkeys.
The results were striking. Conversely, all vaccinated animals survived – regardless of vaccine typeand only five out of six unvaccinated animals died. But the results were more striking for the group that got the mRNA vaccine. The animals given the heat-killed vaccines lost less weight and had significantly fewer lesions than those that were vaccinated with a live attenuated vaccine. Bryan says, in general, the control group had upwards of 1,448 lesions and those vaccinated with the older vaccine registered a high of 607 lesions while those mRNA-vaccinated only developed as up to 54 lesions. In addition, mRNA vaccine shortened the period of time animals showed lesions by > 10 days when compared to the MVA vaccine. This coincided with decreased viral loads in the blood and throat swabs as well, indicating that the treatment may be more safer for reducing transmission.
Conclusion
Ultimately, the results are very promising for this animal study—and hence the mRNA construction of Mobid-19—that it could potentially be a game-changer in human fighting against mpox. This novel strategy will help to preserve the health of their populations and manage future mpox outbreaks more effectively with a better impact on disease symptoms, duration and possibility of transmission.
