Medicines are not usually needed to treat monkeypox. The disease is usually mild and most people will recover within a few weeks without needing treatment. But there are vaccines that can be used to control monkeypox outbreaks, and some countries are already using them. And treatments already exist for those who have become severely ill from the virus.
Monkeypox belongs to Orthopox The genus of viruses, which includes smallpox. Fortunately, due to something called cross-protection, smallpox vaccines also work for monkeypox.
Although the world was declared free of smallpox in 1980, many countries maintain stockpiles of smallpox vaccines for emergencies. For example, the smallpox vaccine is used to protect laboratory workers who accidentally come into contact with smallpox viruses (such as monkeypox or vaccinia – a virus similar to smallpox but less harmful). It is also kept in case of terrorist attacks that might use smallpox as a biological weapon.
The smallpox vaccine can be up to 85% effective in stopping monkeypox virus infection if it is given before people are exposed to the virus.
There are two types of smallpox vaccine. Both types depend on the vaccinia virus. An older type of smallpox vaccine contains the “live” vaccine virus. The main ingredient in this group is ACAM2000, which is approved in the United States to protect people from smallpox.
Although ACAM2000 cannot cause smallpox, the vaccine virus it contains can multiply after the vaccine is given, passing from a vaccinated person to an unvaccinated person who is in close contact with the injection site or any spilled fluid for up to 21 a day after that.
This also means that ACAM2000 can cause many side effects and should not be given to risk groups, such as pregnant or breastfeeding women, and those with compromised immune systems. People with weakened immune systems, including those with HIV, can get very sick from the vaccine.
Another “live” vaccine virus is the Aventis Pasteur smallpox vaccine. It’s not officially approved, but can be made available in case other supplies run out.
A new type of smallpox vaccine, called Imvanex, contains a live but modified form of the vaccinia virus called Ankara vaccinia. Imvanex, made by Danish biotech company Bavarian Nordic, is licensed in the European Union for the prevention of smallpox.
In the United States, the vaccine bears the trade name Jynneos and is licensed to prevent both smallpox and monkeypox in adults at risk for these diseases. Jynneos has been used in the UK for previous monkeypox cases.
Because Northern Bavarian vaccines are made from a modified form of the vaccine virus, they are considered safe for people in high-risk groups.
It usually takes between five and 21 days for someone in close contact with an infected person to develop symptoms of monkeypox (more likely seven to 14 days) so it is difficult to know if giving the vaccine after someone has been exposed to monkeypox will protect them effectively. Full. However, the recommendation in the United States and the United Kingdom is that after a risk assessment, a modified dose of monkeypox vaccine be given to people exposed to monkeypox virus as quickly as possible, ideally within four days, but up to 14 days thereafter .
Apart from vaccines, there are some medications that can be used to treat monkeypox.
One of these drugs is tecovirimat, which stops the spread of infection by interfering with a protein on the surface of the body Orthopoxviruses.
Tecovirimat is approved in the United States to treat smallpox only. It was tested on healthy humans and found to stop the smallpox virus in the lab. However, it has not been tested on people with smallpox or others Orthopoxviruses. However, in Europe tecovitimat was allowed to treat smallpox, monkeypox, and cowpox under exceptional circumstances.
Another antiviral drug that may be used is cidofovir – an injectable drug licensed in the UK to treat serious viral eye infections in people with AIDS.
In the body, cidofovir is converted to the antiviral component cidofovir diphosphate. Because cidofovir stops smallpox in the laboratory, its emergency use may be permitted in cases of smallpox or monkeypox outbreaks.
However, cidofovir is a very potent drug that can damage the kidneys, so a better alternative may be brincidofovir, which is approved in the United States to treat smallpox.
Brincidofovir (trade name Tembexa) is given orally and can be prescribed to people of any age. Its special design helps to get the right amount of drug into the cells to release the cidofovir component and makes it less harmful to the kidneys.
Brincidofovir has been tested in humans for other viral conditions. Its approval for smallpox use in the United States comes from laboratory studies showing that it works against smallpox Orthopoxviruses. For this reason, brincidofovir has also been listed as a potential drug for the treatment of monkeypox.
What we still lack, though, are the data on how effective cidofovir, brinkidofovir and ticofitimat are in treating monkeypox infection in humans. A recent paper published in The Lancet Infectious Diseases looked at the effectiveness of brincidofovir (three patients) and tekovirimat (one patient) in cases of monkeypox between 2018 and 2021 in the UK. The researchers reported poor efficacy of brincidofovir and called for further studies of tecovermate in human monkeypox infections.