FOLLOWING hot on the trail of the recent devastating COVID-19 pandemic, the director-general of the World Health Organisation (WHO) determined that the recent global monkeypox outbreak represented a public health emergency of international concern.
In August 2022 WHO responded by organising the WHO R&D Blueprint; a consultation to discuss knowledge gaps and priority research for monkeypox vaccine research and support member states with surveillance, preparedness and outbreak response activities for monkeypox in affected countries.
Monkeypox has been reported in some African countries in the years before the current outbreak began. These include Cameroon, the Central African Republic, Côte d’Ivoire, DRC, Gabon, Liberia, Nigeria and Sierra Leone.
The recent multi-country outbreak of monkeypox occurred in places where the virus has not been typically found before – i.e.: in Europe, the Americas, the Western Pacific, and countries of the Eastern Mediterranean.
More cases than normal were reported in 2022 in parts of Africa that have previously reported cases, such as Nigeria, DRC and the Central African Republic.
WHO’s Emergency Committee regarding the multi-country outbreak of monkeypox recommended that: “Member States made all efforts to use existing or new vaccines against monkeypox within a framework of collaborative clinical efficacy studies, using standardised design methods and data collection tools for clinical and outcome data, to rapidly increase evidence generation on efficacy and safety, collect data on effectiveness of vaccines (e.g., such as comparison of one or two dose vaccine regimens), and conduct vaccine effectiveness studies.”
Consultations to facilitate the implementation of the recommendations, the WHO R&D Blueprint for epidemics included a global ion on monkeypox vaccine research.
Scientific studies are now underway to assess the feasibility and appropriateness of vaccination for the prevention and control of monkeypox.
During the consultations, global experts reviewed the available evidence in terms of:
Overview of potential study designs;
Plans to evaluate vaccine efficacy/effectiveness of monkeypox vaccines in different countries;
Optimal strategies for the design of randomised and non-randomised studies for vaccine efficacy and effectiveness.
The expected outcomes included:
Consensus critical attributes of optimal study designs;
Outline of the next steps to share information on plans to evaluate and on emerging results.
According to WHO, vaccination against smallpox was demonstrated through several observational studies to be about 85 percent effective in preventing monkeypox. Thus, prior smallpox vaccination may result in milder illness.
While smallpox no longer occurs naturally, the global health sector remains vigilant in the event it could reappear through natural mechanisms, laboratory accident or deliberate release.
To ensure global preparedness in the event of re-emergence of smallpox, newer vaccines, diagnostics and antiviral agents are being developed.
These may also now prove useful for prevention and control of monkeypox, asserts the WHO.
Monkeypox spreads from person to person through close contact with someone who has a monkeypox rash, including through face-to-face, skin-to-skin, mouth-to-mouth or mouth-to-skin contact, including sexual contact.
The virus can also spread from someone who is pregnant to the foetus, after birth through skin-to-skin contact, or from a parent with monkeypox to an infant or child during close contact.
Although asymptomatic infection has been reported, it is not clear whether people without any symptoms can spread the disease or whether it can spread through other bodily fluids.
Pieces of DNA from the monkeypox virus have been found in semen, but it is not yet known whether infection can spread through semen, vaginal fluids, amniotic fluids, breastmilk or blood.
Ulcers, lesions or sores in the mouth can be infectious, meaning the virus can spread through direct contact with the mouth, respiratory droplets and possibly through short-range aerosols.
Possible mechanisms of transmission through the air for monkeypox are not yet well understood and studies are underway to learn more.
Environments can become contaminated with the monkeypox virus, for example, when an infectious person touches clothing, bedding, towels, objects, electronics and surfaces.
Someone else who touches these items can then become infected.
It is also possible to become infected from breathing in skin flakes or virus from clothing, bedding or towels.
This is known as fomite transmission.
WHO’s understanding of how long immunity lasts following monkeypox infection is currently limited.
We do not yet have a clear understanding whether a previous monkeypox infection gives you immunity against future infections and for how long, if so.
Even if you have had monkeypox in the past, you should be doing everything you can to avoid getting re-infected.
However, you should still take all precautions to avoid becoming infected.
During human monkeypox outbreaks, close contact with infected persons is the most significant risk factor for infection.
Health workers and household members are at a greater risk of infection.
Health workers caring for patients with suspected or confirmed monkeypox virus infection, or handling specimens from them, should implement standard infection control precautions.
If possible, persons previously vaccinated against smallpox should be selected to care for the patient. Clinical care for monkeypox should be fully optimised to alleviate symptoms, manage complications and prevent long-term sequelae.
Monkeypox can cause a range of signs and symptoms. While some people have mild symptoms, others may develop more serious symptoms and need care in a health facility.
People at higher risk of severe disease or complications include those who are pregnant, children and persons who are immune compromised.
The most common symptoms of monkeypox include fever, headache, muscle aches, back pain, low energy, and swollen lymph nodes.
This is followed or accompanied by the development of a rash which can last for two-to-three weeks.
The rash can be found on the face, palms of the hands, soles of the feet, eyes, mouth, throat, groin and genital and/or anal regions of the body.
The number of lesions can range from one to several thousands.
Lesions begin flat, then fill with liquid before they crust over, dry up and fall off, with a fresh layer of skin forming underneath.
Symptoms typically last two-to-three weeks and usually go away on their own or with supportive care, such as medication for pain or fever.
People remain infectious until all of the lesions have crusted over, the scabs fallen off and a new layer of skin has formed underneath.
Patients are generally considered infectious until all of their lesions have crusted over, the scabs having fallen off and a new layer of skin formed underneath.
WHO recommends for anyone who has symptoms that could be monkeypox, or who has been in contact with someone who has monkeypox should call or visit a health care provider and seek their advice.
Some countries have, or are developing policies to offer vaccine to persons who may be at risk such as laboratory personnel, rapid response teams and health workers.
WHO is working with all affected countries to enhance surveillance and provide guidance on how to stop the spread and how to care of patients.
Meantime however, surveillance and rapid identification of new cases is critical for reducing the risk of human-to-human transmission outbreak containment.
Monkeypox threatens the world.
Globally, medical epidemiologists from both veterinary and human health sectors are in the throes of clinical research to understand and contain this new viral zoonosis.
Raising awareness of risk factors and educating people about the measures they can take to reduce exposure to the virus in Zimbabwe is the main prevention strategy for monkeypox.
Is Zimbabwe prepared for it?
Dr Tony Monda BSc, DVM, is currently conducting veterinary epidemiology, agronomy and food security and agro-economic research in Zimbabwe.
For views and comments, email: tonym.MONDA@gmail.com