Illness due to monkeypox is usually mild, and most infected people recover within weeks without needing treatment. However, a treatment exists for those who become seriously ill from the virus.
Medicines are not normally required to treat monkeypox. The disease is usually mild and most infected people recover within weeks without needing treatment. But there are vaccines that can be used to control monkeypox outbreaks, which some countries are already using. And treatments exist for those who become seriously ill from the virus.
Monkeypox belongs to the Orthopoxvirus kind of virus, which includes smallpox. Fortunately, due to what is called cross-protection, smallpox vaccines also work for monkeypox.
Although the world was declared smallpox-free in 1980, many countries maintain stocks of smallpox vaccine for emergencies. For example, the smallpox vaccine is used to protect laboratory workers who accidentally come into contact with pox viruses (such as monkeypox or the vaccine – a smallpox virus similar to smallpox but less harmful). They are also kept in case of Terrorist attacks who could use smallpox as biological weapon.
The smallpox vaccine can go up to 85% effective in stopping infection with monkeypox virus if given before people are exposed to the virus.
There are two types of smallpox vaccine. Both types are based on the vaccinia virus. An older type of smallpox vaccine contains “live” vaccinia virus. The principal of this group is ACAM2000which is approved in the United States to protect people against smallpox.
Although ACAM2000 cannot cause smallpox, the vaccinia virus it contains can replicate after the vaccine is given. to transmit from the vaccinated person to an unvaccinated person who comes into close contact with the injection site or any leaking fluid up to 21 days after.
This also means that ACAM2000 can cause many Side effects and should not be administered to risk groups, such as pregnant or breastfeeding women and people with weakened immune systems. People with weakened immune systems, including those who HIVcan get very sick from the vaccine.
The other “live” vaccinia virus is Aventis Pasteur Smallpox Vaccine. It is not officially endorsed, but may be made available if other supplies run out.
A new type of smallpox vaccine, called Imvanex, contains a live but modified form of the vaccinia virus called vaccinia Ankara. Imvanex, made by Danish biotech company Bavarian Nordic, has been licensed in the European Union to prevent smallpox.
In the United States, the vaccine carries the brand name Jynneos and is licensed to prevent both smallpox and monkeypox in adults at risk for these diseases. Jynneos was used United Kingdom in previous cases of monkeypox.
Since the Nordic Bavarian vaccines consist of a modified form of the vaccinia virus, they are considered safe for people in risk groups.
It would usually take between five and 21 days for a person who comes into close contact with an infected person show symptoms monkeypox (and most likely seven to 14 days), so it is difficult to say whether giving the vaccine after a person has been exposed to monkeypox will fully protect them. However, the recommendation in the WE and the UK is that after a risk assessment, people exposed to the monkeypox virus are offered a dose of modified vaccinia Ankara vaccine as soon as possible, ideally within four days, but up to 14 days after.
In addition to vaccines, there are certain medications which could be used to treat monkeypox.
One of these drugs is tecovirimat which stops the spread of infection by interfering with a protein present on the surface of Orthopoxvirus.
Tecovirimat is approved in the United States for the treatment of smallpox only. It was tested on healthy humans and shown to stop the smallpox virus in the lab. However, it has not been tested in people with smallpox or other Orthopoxvirus. However, in Europe tecovitimat has been authorized for the treatment of smallpox, monkeypox and cowpox in exceptional circumstances.
Another antiviral that could be used is cidofovir – an injectable drug licensed in the UK for treat a serious viral eye infection in people with AIDS.
In the body, cidofovir is converted to cidofovir diphosphate, an antiviral ingredient. Since cidofovir stops smallpox in the laboratory, it could be authorized for emergency use in smallpox Where monkey pox epidemics.
However, cidofovir is quite a potent drug and can damage the kidneys, so a better alternative might be the closely related drug brincidofovirwhich was approved in the United States for the treatment of smallpox.
Brincidofovir (brand name Tembexa) is given by mouth and can be prescribed to people of all ages. Its special design helps get the right amount of drug into the cells to release the cidofovir component and also makes it less damaging to the kidneys.
brincidofovir has been tested in humans for other viral diseases. Its approval for use in smallpox in the United States comes from laboratory studies showing that it works against Orthopoxvirus. For this reason brincidofovir is also listed as a potential drug for the treatment monkey pox.
However, what we are still missing are data on the efficacy of cidofovir, brincidofovir and tecovitimat in the treatment of monkeypox infections in humans. A recent article, published in The Lancet Infectious Diseases studied the effectiveness of brincidofovir (three patients) and tecovirimat (one patient) in cases of monkeypox between 2018 and 2021 in the UK. The researchers reported low efficacy of brincidofovir and called for more studies of tecovirimat in human monkeypox infection.