Monkeypox Prevention And Vaccination

Introduction

In July 2022, the World Health Organization declared the multiregional outbreak of Mpox (formerly monkeypox) a public health emergency of international concern.^1,2 Mpox is a disease caused by the monkeypox virus that can cause symptoms similar to smallpox, such as rash, fever and headaches. Aside from potential scar marks and skin discolouration, most patients typically fully recover. However, some people can develop complications and become very sick.^1,3 

Currently, there are no specific treatments for Mpox. What is done is a management of the symptoms, such as taking care of the rash, managing pain and preventing complications.^1,3 

Therefore, prevention measures are important to help stop an outbreak. Mpox can be prevented by avoiding physical contact with someone with the disease and, for people at risk, vaccines can help prevent the infection.^1,3 

Understanding monkeypox

Definition and transmission

Mpox, formerly called monkeypox, is caused by the monkeypox virus, a type of virus belonging to the same family as the ones that cause smallpox and cowpox. This disease is considered a zoonosis disease- an infectious disease that has been transmitted from non-human animals to humans. For example, mice, rats, squirrels, monkeys, primates, hedgehogs, and pigs can be infected with the virus, particularly in African regions.^1,3 

The transmission of Mpox can occur from animals to humans, but the current epidemic is primarily due to human-to-human transmission. The transmission can occur through^1,3 

Signs, symptoms and complications

Mpox symptoms typically manifest within one to three weeks after infection, lasting two to four weeks, and varying according to individual immune system strength. Mpox resembles smallpox and common symptoms include:^1,2,3 

• Fever
• Sore throat
• Headache, muscle aches, and back pain
• Low energy
• Swollen lymph nodes
• Rash

The rash, a characteristic symptom that can appear anywhere on the body, progresses from flat sores to fluid-filled blisters, becoming itchy and painful before crusting over and falling off. Some people may have one or a few skin lesions, while others may have hundreds. When all sores heal and a new layer of skin forms, the person is not considered infectious anymore.^1,2,3  

Although most people fully recover, children, pregnant and people with weak immune systems are at risk for complications from Mpox, such as:^1,2,3 

• Pneumonia
• Corneal infection with loss of vision
• Pain or difficulty swallowing
• Vomiting and diarrhoea, causing severe dehydration or malnutrition
• The skin can become infected and cause serious skin damage
• Inflammatory response in the brain, heart and other organs
• Death

Diagnosis

Because mpox has similarities to other infections, identifying this disease can be difficult. Therefore, testing is very important for accurate diagnosis. The preferred method for detecting Mpox DNA is the Polymerase chain reaction (PCR), which is done with samples taken from skin lesions or other sites if lesions are absent. Blood tests may be useful in some cases, but they have limitations because they do not distinguish between viruses that are related to Mpox.^1,2,3 

Treatment

Currently, there is no specific medication to treat Mpox. The treatment focuses on managing symptoms, preventing complications, and supporting the patient through the disease. Those measures include pain management, ensuring the patient stays hydrated and well-fed, treating secondary bacterial infections, and protecting vulnerable areas like the eyes and genitals. While there are no specific medications for Mpox, antivirals approved for smallpox may be effective for specific cases.^1,2,3 

Preventing Mpox

If you have Mpox, some measures can be taken to help symptoms and prevent infecting others, such as:^1,4

• Stay home and isolate
• Wear masks around others
• Cover lesions until they heal naturally
• Wash hands frequently
• Avoid touching shared items

It's important not to pop blisters or scratch sores, and don’t shave areas with sores until they heal to prevent spreading the rash.¹

If you don’t have Mpox, you can protect yourself by:^1,4

• Avoiding close contact with infected individuals (don’t kiss, hug, or have sex with them)
• Avoiding direct skin-to-skin contact with people displaying rash-like symptoms
• Practising good hygiene and washing your hands often
• Avoiding sharing personal items

Getting vaccinated can also help prevent infection.¹ Check what are the vaccine’s efficacy and recommendations for Mpox below.

Is vaccination for Mpox effective? Who needs it?

Vaccines for Mpox: efficacy and safety 

The Mpox virus has similarities to the other viruses in the same group. Therefore vaccines based on other viruses from the same group may help your immune system to recognise the mpox virus and protect against it.⁵ Today, there are three vaccines used against the Mpox outbreak. All three of them were developed against smallpox and although there is evidence of some protection against mpox, there is still a need for more studies to better evaluate their efficacy.⁶

Regarding safety, historical data show that the called “first-generation smallpox vaccines” (developed in the past, with less technology)⁷ have some side effects, for example:⁵ 

• Pain
• Swelling at the injection site
• Swelling of lymph nodes
• Muscle pain
• Joint pain
• Fatigue
• Headache
• Fever
• Backache
• Abdominal pain
• Nausea

Although rare, there were more serious side-effects observed for this type of vaccine, such as complications caused by the spread of the vaccinia virus in the body, changes in brain function and death.⁵ However, those first-generation vaccines, are not recommended for Mpox at this time.⁶

The new-generation vaccines, especially the third-generation have demonstrated fewer adverse events compared to previous vaccines. For example, a third-generation vaccine, based on a modified virus, was associated with mild side effects including:⁵

• Pain at the site of injection
• Redness, swelling, itching, and hardness in the skin at the site of injection
• Fatigue
• Muscle pain
• Headaches
• Nausea
• Chills

Reports of fever were rare, and cardiac events occurred in around 2% of recipients. Therefore, third-generation vaccines are considered the safest available for preventing Mpox.⁵

Vaccination recommendations: Do you need it?

Mpox vaccination serves two main purposes:^1,5

• Pre-exposure to prevent infection, targeting people at high risk of being infected,
• Post-exposure to make the disease less severe. Ideally, post-exposure vaccination is administered within 4 days of exposure, but can still be effective up to 14 days afterwards. 

The World Health Organization does not recommend pre-exposure vaccination of the population at the time, only for people at risk, especially during an outbreak. People at risk include:^1,2

• Health workers at risk
• Men who have sex with men
• People with multiple sex partners
• Sex workers

Promoting awareness and education about Mpox

The number of Mpox infections in African regions as well as outbreaks occurring in other parts of the world have been increasing.⁵ Since there is no specific medication to treat Mpox and mass vaccination is not recommended, education plays a crucial role in fighting this disease. Particularly in regions where Mpox regularly occurs, educating patients and healthcare workers is essential for preventing it from spreading to other regions. Therefore, it is important to improve:^3,5

• Patient recognition of the disease
• Reporting accuracy
• Diagnostic access
• Increase resources for training, prevention, diagnosis, surveillance, and treatment

Global efforts and surveillance

In July 2022, the global outbreak of Mpox was declared a public health emergency of international concern and the World Health Organization released a strategic plan along with technical guidance documents.^1,8 However, governments and agencies need to recognize the ongoing threat of viral outbreaks and take action on:⁸

• Gathering more data on the efficacy of vaccines and drugs in infected humans
• Increasing global collaborations to ensure that governments work with the private sector in developed and low and middle-income countries to provide the availability of treatments and vaccines
• Increasing diagnostic and surveillance capacity to identify areas and populations where the virus is present
• Informing those at high risk of complications to be protected from community transmission of Mpox
• Engaging with communities in a non-stigmatizing way to increase the understanding and acceptance of public health measures
• Establishing repositories of clinical samples for researchers, including blood, fluids, tissues and lesion material from Mpox infection. 

Summary

Mpox, caused by the monkeypox virus, is a disease that can be transmitted from animals to humans, and from humans to humans. Human-to-human transmission can occur by getting in contact with contaminated bodily fluids such as urine, saliva, semen, and faeces, via direct contact with infected individuals' lesions, in the mouth or on genitals and also by touching contaminated surfaces.^1,3 

The main symptoms include fever, sore throat, rash, headache, muscle aches, back pain, fatigue and swollen lymph nodes. Although most people recover, children, pregnant and people with weak immune systems can develop some complications. Diagnosis relies on PCR testing, and there is no specific medication for Mpox, so treatment focuses on symptom management.^1,2,3  

Preventive measures include isolation, hygiene practices, avoiding sharing personal items and vaccination for high-risk groups.^1,4 Third-generation vaccines developed against smallpox show fewer adverse events and are recommended for pre-exposure in people at high risk and for post-exposure, but more studies are needed to prove their efficacy against Mpox.^5,6 Education and surveillance are vital for managing outbreaks, with global efforts needed to gather data, increase collaboration, improve diagnostics and treatment, and engage communities to effectively fight this disease.^3,5,8