ON July 23, World Health Organisation Director-General Tedros Adhanom Ghebreyesus took the unprecedented step and declared the monkeypox outbreak a “public health emergency of international concern” – the highest global alert level for a disease outbreak.

Following this and with 45 cases in Australia, Chief Medical Officer Paul Kelly declared last week that monkeypox is now a “communicable disease incident of national significance”.

So what is monkeypox? And who’s eligible for a vaccine?

Most cases in the current global outbreak are occurring among men who have sex with men. How can this group and others who are at risk protect themselves?

What is monkeypox?

Monkeypox is not a new disease, it was found in the late 1950s in lab primates in Denmark, and was first diagnosed in humans in an infant in the 1970s in the Democratic Republic of Congo.

In the past, monkeypox has mainly been transmitted from infected animals to humans (it is a zoonotic disease), and has been endemic to West and Central Africa. Transmission can occur through contact with infected animals including rodents, mice, rats, squirrels, monkeys and other primates.

But in this outbreak we’re seeing human-to-human transmission.

There are two distinct strains of monkeypox. These are the Central African and the West African types, the latter of which is believed to be one linked to the current global outbreak.

According to US Centers for Disease Control and Prevention (CDC) data, 23,620 cases have been reported since May in 80 countries, with 73 countries that had no previous reported monkeypox cases.

There have been at least seven deaths.

Most of the cases in Australia have been in New South Wales and Victoria, among returned travellers and men who have sex with men, and in the age group 21-40 years.

The declaration that monkeypox is now a disease of national significance means the outbreak requires national policies, interventions and public health messaging, with the deployment of more resources to assist affected areas and groups most at risk.

Symptoms and transmission

The incubation period – the time taken to develop the disease after exposure to the virus – is usually around 6-13 days.

Transmission generally requires close contact with an infected person. It can be transmitted via respiratory droplets.

It can also be transmitted through direct contact with body fluids or the rash (“lesions”), often through skin-on-skin contact, or indirect contact such as through contaminated clothing or bedding.

Transmission may occur from people without symptoms, or with barely-detectable symptoms.

Symptoms are similar to smallpox, though less severe. They can include:

• fever
• headache
• aches
• fatigue
• sweats and chills
• cough and sore throat
• a rash that can look like blisters or pimples, which can be painful. These “lesions” typically go through several stages before eventually falling off.

The CDC says most people who get the virus will develop the rash.

A study in the British Medical Journal published last week also found 88 per cent of 197 people with monkeypox in London had lesions on their genitals or anus.

Symptoms generally last between two and four weeks, and the disease usually resolves on its own. Most adults with a healthy immune system won’t have severe illness and won’t experience long-term harmful effects.

There’s no specific treatment for monkeypox yet. People with the infection should be given supportive treatment and light dressings on the rash, depending on the symptoms. Antivirals such as “tecovirimat” have been made available to patients in some countries who have or are at high risk of severe disease, such as being immunocompromised.

People with the infection should isolate immediately for the duration of the illness – usually two to four weeks, until the lesions heal.

Higher risk groups

Monkeypox can affect anyone. But men who have sex with men are at higher risk at the moment. WHO Director-General Tedros Adhanom Ghebreyesus said 98 per cent of cases so far are among men who have sex with men.

It’s important we provide as much information about the virus as possible, and it’s absolutely crucial we do this in a way that is not stigmatising.

This outbreak is seeing cases spread via close prolonged contact from sexual activity in the LGBTIQ+ group. Many from this group want to take proactive actions to help their community.

Specific actions governments can take include:

• prioritising vaccines as a matter of urgency for those most at risk
• targeting public health messaging so the LGBTIQ+ community can make informed decisions.

Actions individuals can take include:

• maintaining contact details of sexual partners in case of need to follow up
• avoiding sex if you have a rash until you get tested
• considering avoiding skin to skin contact during large gatherings
• if diagnosed with monkeypox, avoiding close physical contact, including sexual contact, with other people for the duration of the illness.

The CDC says condoms may help lower the risk of spread if the lesions are confined to the genital and/or anal region, but they’re likely not enough to prevent transmission on their own.

Who should have the vaccine?

Australia has secured small supplies of two smallpox vaccines, which provide protection against monkeypox.

The vaccine advisory body, the Australian Technical Advisory Group on Immunisation (ATAGI), has recommended key risk groups be administered the vaccines. They include:

• those identified as a high risk monkeypox contact in the past 14 days
• men who have sex with men who are at high risk of exposure. This includes those living with HIV, or with a recent history of a high number of sexual partners or group sex
• sex workers, with clients in high-risk categories
• anyone in the risk categories planning travel to a country experiencing a significant outbreak, with vaccination recommended four to six weeks prior to leaving.

ATAGI has stated that vaccination within four days of exposure to someone who’s infectious with monkeypox will provide the highest chance of preventing disease.

Avoiding close contact with people who have the infection can help prevent transmission. Monkeypox doesn’t spread as easily as the coronavirus and can be kept under control if we are cautious.

The need for vaccine equity and global health leadership

We can’t repeat the “vaccine nationalism” we’ve seen during covid with rich countries hoarding vaccine doses, as this will unjustly prolong the outbreak.

Currently, according to The Lancet medical journal, a smallpox vaccine sold as “Jynneos” in the US costs around US$100 a dose. The WHO has called on countries and manufacturers to ensure the vaccines, as well as diagnostics and therapeutics, are made available “at reasonable cost” where most needed.

Thus we have major political and policy challenges ahead and will need strong global health leadership going forward.

Jaya Dantas, Deputy Chair, Academic Board; Dean International, Faculty of Health Sciences and Professor of International Health, Curtin University. This article is republished from The Conversation.