The EMA's Committee for Medicinal Products for Human Use (CHMP) has initiated a data review to expand the use of the smallpox vaccine, Imvanex, to include protection of humans from monkeypox disease.
Currently, the Imvanex vaccine is licensed in the EU for the prevention of smallpox in adults. It contains a live modified form of the damalitis virus called "vaccinia Ankara", which is related to the smallpox virus. It is also considered a potential vaccine for monkeypox because of the similarity between monkeypox virus and smallpox virus.
The decision to initiate this review was based on the results of laboratory studies (non-clinical data) suggesting that the vaccine activates the production of antibodies that target monkeypox virus and may help protect against the disease.
Supplies of Imvanex are currently very limited in the EU. Imvanex is available under the trade name Jynneos in the US market where it is licensed to prevent both monkeypox and smallpox.
Recommendations for the use of Jynneos
Considering the limited availability of Imvanex, the EMA's Emergency Task Force (ETF) recommended the use of Jynneos in the EU to provide protection against monkeypox disease. The Task Force issued this recommendation to support national authorities who may decide, as an interim measure, to import Jynneos from the US in view of increasing infection rates across the EU.
The ETF noted the US FDA's conclusion that the efficacy of Jynneos in preventing monkeypox disease can be inferred from antibody responses against the damalitis virus in clinical studies. In addition, animal studies, including in primates, showed that the vaccine protected animals exposed to monkeypox virus and enhanced pre-existing immunity induced by previous generations of smallpox vaccines.
The most commonly reported side effects of Jynneos are pain, redness, swelling, itching and hardening at the injection site, muscle pain, headache and fatigue.
The ETF provided its recommendations for the response to monkeypox in multiple EU countries as part of its public emergency preparedness activities, which include providing recommendations to support regulatory activities and assessments for pharmaceutical products.
More about the vaccine
Jynneos/Imvanex is expected to prepare the body to defend against smallpox and monkeypox infection. It contains a modified form of the damalitis virus called vaccinia Ankara, a virus closely related to smallpox virus and monkeypox virus, but which does not cause disease in humans and cannot replicate in human cells. Because of the similarity of smallpox virus and monkeypox virus, antibodies produced against the virus are also expected to protect against monkeypox.
When a person is given the vaccine, the immune system recognizes the virus in the vaccine as "foreign" and produces antibodies against the virus. When the person comes into contact with this virus or similar viruses again, these antibodies along with other components of the immune system will be able to kill the viruses and help protect against disease.
More about monkeypox
Monkeypox is a rare disease caused by infection with the monkeypox virus, with symptoms similar to smallpox. Monkeypox begins with fever, headache, muscle aches and exhaustion and can be fatal, although it is typically milder than smallpox. It is transmitted to humans by various wild animals, such as rodents and primates, but can also be transmitted between humans after close contact. The current spike in cases reported as of May 2022 relates to the first cases recorded outside Africa with no link to endemic areas.
More about the procedures
The review on the use of Imvanex against monkeypox was initiated based on ETF recommendations. The EMA will now evaluate the available data pending a formal application from the company marketing the vaccine to extend the use of Imvanex. This type of review process is one of the ways in which EU authorities are working to ensure that EU Member States have timely access to a monkeypox vaccine.
ETF issued recommendations on the use of Jynneos during the Imvanex review as part of EMA's preparedness activities. The working group continues to monitor the outbreak of monkeypox in Europe and is in close contact with public bodies, including the European Centre for Disease Prevention and Control (ECDC) and the European Health Emergency Preparedness and Response Authority (HERA), as well as with development agencies to assist in the availability of medicines for the prevention and treatment of monkeypox.
(AF)
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