EXPLAINED | Is There A Treatment For Monkeypox? See List Of Therapeutics And Vaccines Available

A monkeypox outbreak can be controlled with the help of smallpox vaccine, cidofovir, ST-246, and vaccinia immune globulin (VIG).

Representative Photo | Based on data in animal and human studies, an antiviral agent known as tecovirimat that was developed for smallpox was licensed by the European Medical Association (EMA) for monkeypox in 2022

Source : ABP Live

New Delhi: The Centers for Disease Control and Prevention (CDC) is tracking "multiple clusters" of monkeypox reported in non-endemic countries in the past two weeks, including the United Kingdom, Portugal, and Spain.

The CDC confirmed the first case of monkeypox in the United States on May 18, 2022. The patient was from Massachusetts, and had recently travelled to Canada, media reports said.

On May 20, monkeypox was reported in New York City, health officials confirmed. A "presumptive case" was detected in Broward County, Florida, NBC South Florida reported. Several cases have been detected in Canada also.

Belgium is the first country to mandate a 21-day quarantine for monkeypox patients, CNBC reported. The UK recommends people at "high risk" for monkeypox to self-isolate themselves for 21 days to reduce transmission risk.

As many as 92 laboratory confirmed cases, and 28 suspected cases of monkeypox with investigations ongoing, have been reported to the World Health Organization (WHO) from 12 Member States not endemic for monkeypox virus, across three WHO regions, as of May 21, 13:00 CET (4:30 pm IST). Also, no associated deaths due to monkeypox have been reported to date. 

Britain, Spain, Portugal, Italy, and Sweden are the European countries where monkeypox cases have been reported. These countries are far from West and Central Africa where monkeypox outbreaks are typically reported. 

Monkepox is a rare zoonotic disease, which is an infectious disease transmitted between species from animals to humans or from humans to animals. It is caused by infection with monkeypox virus, and does not spread easily between people. Though most people recover from monkeypox within a few weeks as it is usually a mild, self-limiting disease, some individuals can suffer from severe illness. 

What Treatments Are Available For Monkeypox?

No specific treatments are available for monkeypox infection at present. However, monkeypox outbreaks can be controlled, according to the CDC.

A monkeypox outbreak can be controlled with the help of smallpox vaccine, cidofovir, ST-246, and vaccinia immune globulin (VIG). Using the best available information about the benefits and risks of smallpox vaccination and drug use, CDC guidance was developed for the prevention and management of monkeypox and other orthopoxvirus infections. 

Therapeutics For Monkeypox

According to the World Health Organization, clinical care for monkeypox should be fully optimised to alleviate symptoms, manage complications, and prevent long-term sequelae, which is the consequence of a previous disease or injury. Adequate nutritional status can be maintained throughout consumption of fluids and healthy food. 

The WHO recommends that secondary bacterial infections should be treated as indicated.

Tecovirimat (ST-246)

Based on data in animal and human studies, an antiviral agent known as tecovirimat that was developed for smallpox was licensed by the European Medical Association (EMA) for monkeypox in 2022. However, tecovirimat is not yet widely available. 

Tecovirimat should ideally be monitored in a clinical research context when used for patient care, with prospective data collection. 

According to the CDC, data is not available on the effectiveness of tecovirimat in treating human cases of monkeypox. Tecovirimat is effective in treating orthopoxvirus-induced disease, studies using a variety of animal species have shown. The drug was found to be safe and tolerable with only minor side effects in human clinical trials. 

The Strategic National Stockpile currently stockpiles tecovirimat. Yet, the use of tecovirimat is administered as an Investigational New Drug (IND).

Cidofovir And Brincidofovir (CMX001)

Though data is not available on the effectiveness of Cidofovir and Brincidofovir in treating human cases of monkeypox, both have proven capacity against poxviruses in vitro and animal studies. 

Whether or not a person with severe monkeypox infection will benefit from treatment with either antiviral is not known. Despite this, the use of these antivirals may be considered in such instances. 

The CDC states that Brincidofovir may have an improved safety profile over Cidofovir. Both Brincidofovir and Cidofovir have been used during treatment of cytomegalovirus infections. Cytomegalovirus is a common virus which is retained in one's body forever after infection with the virus. The genus belongs to the order Herpesvirales, with humans and monkeys serving as natural hosts for the virus. During treatment of these infections with Brincidofovir, serious renal toxicity or other adverse events have not been observed, compared to treatment using Cidofovir.

Vaccination Against Monkeypox

Vaccination against smallpox was demonstrated through several observational studies to be about 85 per cent effective in preventing monkeypox, which means that prior smallpox vaccination may result in milder illness. Smallpox vaccines can protect people from getting monkeypox because the monkeypox virus is closely related to the virus causing smallpox. 

Evidence of prior vaccination against smallpox is usually found as a scar on the upper arm, according to the WHO. The original or first-generation smallpox vaccines are no longer available to the general public at present. Laboratory personnel and health workers often receive a more recent smallpox vaccine to protect them in the event of exposure to orthopoxviruses in the workplace. 

In 2019, a newer vaccine based on a modified attenuated vaccinia virus (Ankara strain) was approved for the prevention of monkeypox. The new vaccine is a two-dose vaccine and has limited availability. 

The vaccinia virus can provide cross-protection for the immune response to orthopoxviruses. Therefore, smallpox and monkeypox vaccines are developed in formulations based on the vaccinia virus. 

Monkeypox And Smallpox Vaccines

Imvamune or Imvanex (JYNNEOS), is a vaccine that has been licensed in the United States to prevent monkeypox and smallpox. 

A clinical study on the immunogenicity of JYNNEOS and efficacy data from animal studies have shown that JYNNEOS is effective against monkeypox. 

Vaccination after a monkeypox exposure may help prevent the disease or make it less severe, according to experts.

ACAM2000, which contains a live vaccinia virus (closely related to the virus that causes cowpox), is licensed for Immunisation in people who are at least 18 years of age, and at high risk for smallpox infection, and can also be used in people exposed to monkeypox when administered under an expanded access investigational new drug protocol. 

Since smallpox vaccine is not currently available to the general public, the CDC will establish guidelines explaining who should be vaccinated, in the event of an outbreak of monkeypox in the US.

Vaccinia Immune Globulin (VIG)

No data is available on the effectiveness of vaccinia immune globulin (VIG) in treatment of monkeypox complications. VIG has no proven benefit in the treatment of smallpox complications, and its use is administered under an IND. 

Whether a person with severe monkeypox infection will benefit from treatment with VIG is not known. However, the use of this vaccine may be considered in such instances.