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EMA’s
Emergency Task Force advises on intradermal use of Imvanex/Jynneos against
monkeypox |
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EMA’s Emergency Task Force (ETF) has reviewed data on the
monkeypox vaccine Imvanex used as an intradermal injection (given just
below the top layer of the skin). The
vaccine is only authorised
for subcutaneous injection (injection under the skin). However, when given
intradermally, a smaller dose of the vaccine can be used. Given the currently
limited supply of the vaccine, this means that more people can be vaccinated. The ETF reviewed data from a clinical trial involving around 500 adults, which compared the vaccine given either intradermally or subcutaneously, as 2 doses with a 4-week interval between each dose. People receiving the vaccine intradermally received one fifth (0.1 ml) of the subcutaneous dose (0.5 ml) but produced similar levels of antibodies to those who received the higher subcutaneous dose. The ETF
cautioned that there was a higher risk of local reactions (e.g.
longer-lasting redness, and thickening or discoloration of the skin) after
intradermal injections. The ETF
noted that there is no information available on the maximum number of 0.1 ml
doses that can be withdrawn from the authorised presentation (0.5 ml
suspension) and recommended using low-dead volume syringes to optimise the
number of doses that can be extracted. The ETF also emphasised the importance
of giving intradermal injections correctly, recommending that only healthcare
professionals with experience giving injections intradermally should
administer the vaccine this way. Further information for healthcare
professionals is included in the ETF’s statement. Taking
into account all these considerations, national authorities may decide as a
temporary measure to use Imvanex as an intradermal injection at a lower dose
to protect at-risk individuals during the current monkeypox outbreak while
supply of the vaccine remains limited. Imvanex
was first authorised under exceptional circumstances in 2013 for the
protection against smallpox. Following an application to extend its use, it
was authorised for protecting against monkeypox disease on 22 July 2022. The ETF’s
advice has been issued to address the outbreak of monkeypox in multiple EU
countries in the context of its public health emergency response activities,
which include giving advice to support regulatory activities and
product-related assessments. More about the medicine Imvanex
prepares the body to defend itself against infection with the variola
(smallpox), monkeypox and vaccinia viruses. It contains an attenuated form of
the vaccinia virus called ‘modified vaccinia virus Ankara’ (MVVA), which is
closely related to the smallpox and monkeypox viruses but does not cause
disease in humans and cannot reproduce in human cells. Because of the
similarity between these viruses and MVVA, antibodies produced against MVVA,
together with other components of the immune system, are expected to protect
against monkeypox, smallpox and vaccinia. When a
person is given the vaccine, the immune system recognises the virus in the
vaccine as ‘foreign’ and makes antibodies against it. When the person later
comes into contact with similar viruses, the antibodies and other components
of the immune system will be able to kill those viruses and help protect
against disease. The
marketing authorisation holder for Imvanex is Bavarian Nordic A/S. More about monkeypox Monkeypox
is a rare disease caused by infection with the monkeypox virus, which causes
symptoms similar to those of smallpox. Monkeypox begins with fever, headache,
muscle aches, exhaustion and lymph node swelling. A rash commonly develops
one to three days after the onset of fever, first appearing on the face and
spreading to other parts of the body, including hands and feet. Monkeypox
can be fatal, even though it is typically milder than smallpox. It is
transmitted to people from various wild animals, such as rodents and
primates, but can also be transmitted between people following direct or
indirect contact. Current outbreaks reported since May 2022 are the first
reported outside of Africa with no links to endemic areas. On 23 July 2022,
the World Health Organisation declared the monkeypox outbreak a public health
emergency of international concern. (AP) |
