Treatment Options for Monkeypox

Posted 2024-02-12 11:25:53

With the recent global outbreak of monkeypox cases, concerns around treatment options for the virus have grown. While monkeypox is rarely fatal, the virus can cause severe symptoms. Effective treatments are needed to reduce suffering and control further spread.

Vaccines
The smallpox vaccines have proven effective against monkeypox due to the similarities between the viruses. Two vaccines are currently being used or studied - JYNNEOS and ACAM2000.

JYNNEOS
JYNNEOS, also known as Imvamune or Imvanex, is a newer third-generation smallpox vaccine produced by Bavarian Nordic. It has been approved by the FDA for prevention of both smallpox and monkeypox.

Early studies found JYNNEOS to be 85% effective in monkeypox treatment when given before exposure. It has a good safety profile and fewer side effects than older smallpox vaccines. Several countries like the US have ordered millions more doses of JYNNEOS to bolster vaccination campaigns.

ACAM2000
ACAM2000, also called Dryvax, is an older smallpox vaccine used during the smallpox eradication program. It contains live vaccinia virus and has more significant side effects than JYNNEOS.

ACAM2000 is still stockpiled in case of a smallpox attack. It provides near 100% protection against monkeypox if given before exposure and may offer some benefit even after exposure. However, its side effects raise concerns about widespread use during the current outbreak.

Antivirals

For patients who contract monkeypox, antiviral treatments can help reduce symptoms. Two antivirals are being used - tecovirimat and brincidofovir.

Tecovirimat
Tecovirimat, sold under the brand name TPOXX, is an antiviral specifically approved to treat smallpox. It works by inhibiting the spread of the virus within infected cells.

In a study of monkeypox patients, tecovirimat was found to significantly shorten the duration of illness when given early. The US has emergency use authorization for tecovirimat in monkeypox patients. It is generally well-tolerated with few drug interactions.

Brincidofovir
Brincidofovir is a broad-spectrum antiviral developed to treat smallpox, cytomegalovirus and adenovirus infections. It is not FDA approved but has been made available for compassionate use in monkeypox patients through an expanded access protocol.

Preliminary findings show brincidofovir may offer benefit when started early in monkeypox infection. However, more study is still needed regarding safety and efficacy. Its restricted availability also limits its usefulness at this stage of the outbreak.

Other Experimental Treatments

Beyond approved vaccines and antivirals, researchers are exploring other novel treatment angles for monkeypox:

- Cidofovir - An antiviral injection used to treat CMV retinitis. Has shown promise against monkeypox in test tube studies. More research is ongoing.

- ST-246 - An experimental antiviral that may work synergistically with tecovirimat or brincidofovir. Currently in preclinical testing for monkeypox.

- Monoclonal antibodies - Laboratory-developed Y antibodies that could be given to recently exposed individuals for post-exposure prophylaxis. Requires further research.

- Small interfering RNAs (siRNAs) - A type of nucleic acid molecule that could potentially disrupt viral replication. Early stage research only.

- Convalescent plasma - Immune plasma collected from recovered monkeypox patients. May confer short term protection worth studying.