EMA Announces Advice on Switch that Could Increase The Monkeypox Vaccine Supply

On August 19, the European Medicines Agency (EMA) announced their Emergency Task Force (ETF) reviewed data from a clinical trial testing Imvanex, a vaccine for monkeypox. The trial tested the possibility of administering the vaccine intradermally in smaller doses. The switch could increase the monkeypox vaccine supply.

Related Article: EMA Begins Review of SK biosciences’ New Non-mRNA COVID-19 vaccine

The Shortage of Vaccines for Poxviruses 

The smallpox virus plagued humanity for thousands of years, causing serious symptoms such as fever, muscle aches, severe fatigue, and blisters to spot across the body. However, the World Health Organization (WHO) declared the lethal disease eradicated on May 8, 1980. This was due to the rise of immunization through vaccines like Imavanex

Imavanex gained approval for smallpox in adults in 2013. The vaccine contains an inactive version of the virus. When injected, the immune system reacts to the foreign body, developing defense mechanisms that it remembers for the subsequent encounter with the virus.

However, 2022 saw another virus in smallpox’s family unleashed upon the world: monkeypox. Monkeypox causes much the same symptoms as smallpox. However, because of their similarities, institutions also recommend using vaccines like Imavanex for monkeypox. The issue arises because the production of vaccine doses cannot keep up with the infection rate. Now, officials are rethinking the distribution of doses to keep the maximum amount of the population inoculated. 

Intradermal versus Subcutaneous injection: which method works?

Typically, medical professionals administer vaccines via subcutaneous injection, meaning under the skin. Imavanex is no different, as its approval lists it as only injectable in this way. However, a recently conducted clinical trial tested whether Imavanex could be administered via intradermal injection, meaning just below the top level of the skin. 

The trial consisted of around 500 adults either receiving the subcutaneous injection or the intradermal injection. However, the intradermal injection only contained a fifth of the dose of the subcutaneous injection. Despite that, the ETF found in their review that both sets of patients displayed production of similar levels of antibodies. 

However, the trial found a higher risk of local reactions in intradermal injections. In addition, the ETF warned that only experienced medical professionals should administer intradermal injections due to the risks involved. 

This advice follows a similar move made by the FDA earlier this month. The FDA issued an emergency use authorization of intradermal injections for the JYNNEOS vaccine for individuals at high risk of monkeypox infection. Similarly, the switch to intradermal administration increase the monkeypox vaccine supply by five-fold. 

Due to the trial’s results, the ETF advised national authorities to make their decision considering all of the findings. The decision to temporarily stretch vaccines now falls to national authorities.

Author

Max Heirich