Jynneos vaccine offers protection against Mpox, new studies show

The Jynneos vaccine offers real protection against mpox, and two doses appear to be more effective than one, according to three new observational studies published Thursday.

< p class="css-at9mc1 evys1bk0">The effectiveness of two doses of the vaccine ranged from 66% to 88%, depending on the study, while the effectiveness of a single dose ranged from 36% to 75%. The researchers also concluded that what is called intradermal dosing - which involves injecting the vaccine between the layers of the skin, rather than underneath, and requires only a fifth of the dose - offers protection to roughly equivalent to conventional treatment under the skin. injection.

The research was published in a weekly report by the Centers for Disease Control and Prevention and in the New England Journal of Medicine.

Many questions remain about the vaccine, which had not been widely used before last summer's outbreak of mpox, formerly called monkeypox, largely among men who have sex with men. None of the new studies were randomized controlled trials, and some of the analyzes were small.

Further work is needed to determine the vaccine's effectiveness in immunocompromised people, how long the protection lasts and whether it varies depending on how the shots are delivered.

ImagePreparing doses of the Jynneos mpox vaccine at a clinic in Tucson, Arizona, last summer.Credit...Rebecca Noble/Reuters

Why it matters: A resurgence is possible.

In the United States, there have been more than 30,000 cases of mpox over the past year, with cases declining sharply after peaking last summer. Mpox cases have also declined globally and the World Health Organization has said