Mpox: A Reoccurring Health Challenge

Posted on 2024-10-04

In May 2022, just as the COVID-19 pandemic was easing, there was a global outbreak of mpox. Before this, there was only one contained outbreak of this disease outside of Central Africa, where mpox is endemic (1). 

On the 15th of August 2024, mpox, formerly known as monkeypox, was reinstated as a public health emergency of international concern by the World Health Organisation (WHO) (2). A recent rise in cases of a new mpox strain, clade Ib, in the Democratic Republic of Congo, has now spread to neighbouring countries, and the European and Asian continents, raising concern that a potential pandemic might be on the horizon (3).

Mpox is a zoonotic infectious disease caused by the monkeypox virus (MPVX), a double-stranded DNA virus, and a member of the Orthopoxvirus genus of the Poxviridae family. Several other diseases are caused by viruses of the same genus, such as variola (smallpox) and vaccinia (cowpox) viruses (4). Abbexa offers various Orthopoxvirus products, such as vaccinia antibodies, human vaccinia protein, and camelpox ELISA kit, among others.

There are two strains of MPVX, clade I, formerly Congo Basin clade, and clade II, formerly West African clade. Clade II consist of two subclades, IIa and IIb. Clade IIb caused the global outbreak in 2022, and the current outbreak is linked to the newly identified variant, Ib (4).

Mpox can infect humans via contact with animals, monkeys and rodents.

The primary mode of transmission is by direct contact with infected animal fluids, blood or wounds, as well as through person-to-person contact. Even though biologically the virus affects both genders, in the previous global outbreak, mpox predominantly affected males (5).

The progression of mpox symptoms unfolds through various clinical stages, characterised by distinct alterations in skin appearances and lesions. First., mucosal lesions develop in the oral cavity, followed by the development of these in the face and limbs. Other associated symptoms are fever, arthromyalgia and lymphadenopathy. Overall, mpox infections may last up to 21 days, with symptoms persisting for up to 4 weeks (6).

The early detection of infection by MPVX is essential to contain the spread of the disease. Confirmation of MVPX infection is based on nucleic acid amplification testing (NAAT), using real-time polymerase chain reaction (RT-PCR), used alone or in combination with sequencing, and enzyme-linked immunosorbent assay (ELISA) (7). Abbexa supports mpox laboratory detection by providing Human Monkeypox Virus quantitative ELISA kits, RT-PCR kits, and Rapid Test kits. 

Currently, there are no specific treatments for mpox, but antiviral drugs can be used to help severe cases of the disease. For example, tecovirimat, cidofovir and its prodrug brincidofovir have been used by clinicians to help treat mpox patients. However, there is a lack of evidence of the effectiveness of these in resolving symptoms, as they were either originally developed for smallpox or inhibit general DNA processes to inhibit virus replication, respectively (8).

Similar to other antiviral drugs, smallpox vaccines can offer protection against mpox. Currently, two vaccines have been confirmed to be effective for mpox vaccination, ACAM2000 and JYNNEOS. The latter is more widely recommended for immunisation programmes by healthcare organisations, such as the NHS and CDC. JYNNEOS is based on the non-replicating modified vaccinia Ankara virus, referred to as MVA-BV. Following the recent outbreak of the disease, WHO has prequalified this vaccine for mpox vaccination, meaning that it is now recommended for general administration (9). 

During its replicating cycle, mpox has two infectious virions, intracellular mature virions (IMV) and extracellular enveloped virions (EMV). Membrane and envelope proteins located in the outer layer of virions are essential for attachment to host cells. Hence, these proteins are being researched as potential MPVX-specific vaccine candidates. Of these, A29L, H3L and E8L are key vital proteins associated with IMV and EEV cell entry (10). Abbexa aids vaccine and general mpox vaccine and monkeypox research by offering a range of key proteins and antibodies, such as A29L, H3L, and E8L.

Abbexa offers an extensive range of mpox products. Please go to Abbexa's Monkeypox page for more detailed information about these.

References

1. Sharma A, Priyanka, Fahrni ML, Choudhary OP. "Monkeypox outbreak: new zoonotic alert after the COVID-19 pandemic." Int J Surg. 2022 

2. World Health Organization (WHO). WHO Director-General declares mpox outbreak a public health emergency of international concern [Internet]. 2024 Aug 14. Available from: https://www.who.int/news/item/14-08-2024-who-director-general-declares-mpox-outbreak-a-public-health-emergency-of-international-concern 

3. McCollum AM, Shelus V, Hill A, et al. "Epidemiology of human Mpox-worldwide, 2018-2021." MMWR Morb Mortal Wkly Rep. 2023

4. Beer EM, Rao VB. "A systematic review of the epidemiology of human monkeypox outbreaks and implications for outbreak strategy." PLoS Neglected Trop Dis. 2019.

5. Fine PEM, Jezek Z, Grab B, Dixon H. "The transmission potential of monkeypox virus in human populations." Int J Epidemiol. 1988. 

6. Hraib M, Jouni S, Albitar MM, Alaidi S, Alshehabi Z. "The outbreak of monkeypox 2022: an overview." Ann Med Surg. 2022. 

7. McCollum AM, Damon IK. "Human monkeypox." Clin Infect Dis. 2014. 

8. Adler H, Gould S, Hine P, et al. "Clinical features and management of human monkeypox: a retrospective observational study in the UK." Lancet Infect Dis. 2022. 

9. Bertran M, Andrews N, Davison C, et al. "Effectiveness of one dose of MVA-BN smallpox vaccine against mpox in England using the case-coverage method." Lancet Infect Dis. 2023. 

10. Wang Y, Yang K, Zhou H. Immunogenic proteins and potential delivery platforms for mpox virus vaccine development: A rapid review. Int J Biol Macromol. 2023;245:125515.