Bavarian Nordic’s Jynneos highlights unmet need for mpox prevention in HIV patients: GlobalData

A recent study reveals that a single dose of Bavarian Nordic’s Jynneos vaccine demonstrated 58 per cent overall effectiveness in preventing mpox infection. Among the participants without HIV, effectiveness rose to 84 per cent, while those with HIV showed only 35 per cent effectiveness. These findings underscore the critical need for enhanced mpox prevention strategies for vulnerable, high-risk populations, particularly those with HIV, says GlobalData.

The study, which was carried out at Charité – Universitätsmedizin Berlin and published in The Lancet Infectious Diseases, marks the first comparison of effectiveness between individuals with and without HIV.

Stephanie Kurdach, Infectious Disease Analyst at GlobalData, comments, “Mpox is a viral illness, spread through close contact with another infected individual, contaminated objects, or infected animals. Symptoms can include a blistering rash, fever, muscle aches, sore throat, and swollen lymph nodes. While mpox symptoms are often mild, immunocompromised patients, such as those with uncontrolled HIV, are at a greater risk of severe disease, hospitalisation, and death from this infection.”

According to the US Centers for Disease Control and Prevention (CDC), the ongoing clade II 2022 mpox outbreak has been responsible for over 100,000 infections among 122 countries to date across North America, South America, Africa, Europe, Asia, and Australia. Clade II mpox has a >99 per cent survival rate. Conversely, clade I is more likely to cause severe illness and death, particularly among immunocompromised individuals. A clade I outbreak has been ongoing in Central and Eastern Africa since 2024 and has been responsible for over 21,000 infections to date.

Jynneos, also marketed under the name Imvanex, is approved in the US and Canada as a 2-dose vaccine for the prevention of mpox and smallpox in high-risk individuals 18 years of age and older, and in Europe for high-risk individuals 12 years of age and older. The reduced effectiveness of Jynneos in HIV-positive patients is likely attributable to a reduced T-cell response following vaccination in comparison to HIV-negative individuals, according to the study researchers. Ensuring patients receive the full 2-dose vaccination regimen is therefore particularly important for those with HIV.

Kurdach continues: “According to GlobalData, there are currently only two other vaccines approved for the prevention of mpox, KM Biologics’ mpox LC16m8 vaccine, and Emergent BioSolutions’ ACAM2000. Of these, the LC16m8 vaccine has been shown to be safe and effective in people with well-controlled HIV.”

In the Jynneos study, over 3,600 participants received two doses of the mpox vaccine to analyse vaccine safety. Local reactions occurred in 70 per cent of individuals after the first dose and 57 per cent of individuals after the second dose. Systemic reactions occurred in 22 per cent of individuals after the first dose and 18 per cent of individuals after the second dose. Severe local and systemic reactions were rare.

Kurdach concludes: “The recent safety and effectiveness data regarding mpox vaccination by Jynneos is important and timely given the ongoing, global outbreak. Unfortunately, there are still clear unmet needs for more research on mpox in patients with HIV and increased, effective vaccination options for this at-risk population.”