Jynneos vaccine protects against Mpox, say studies – 05/22/2023 – Health

The Jynneos vaccine, made by pharmaceutical company Bavarian Nordic, offers real-world protection against mpoxy (monkeypox), and two doses appear to be more effective than one, according to three new observational studies published Thursday.

The effectiveness of two doses of the vaccine varies between 66% and 88%, depending on the study, and the effectiveness of a single dose, between 36% and 75%.

The researchers also concluded that so-called intradermal dosing — which involves injecting the vaccine between layers of skin rather than under the skin and requires only one-fifth the usual dose — provides protection roughly equivalent to that of conventional subcutaneous injection.

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

Many questions remain about the vaccine, which was not widely used until the outbreak of mpoxide, formerly called monkeypox, last summer that largely affected men who have sex with men.

None of the new studies were randomized controlled trials, and some of the analyzes were small.

Further studies will be needed to determine the effectiveness of the vaccine in immunocompromised people, how long protection lasts, and whether this time varies according to how the doses are administered.

There have been more than 30,000 cases of Mpox in the last 12 months in the United States. The number of cases has dropped sharply after peaking last summer.

Mpox cases have also been decreasing in the rest of the world, and earlier this month the World Health Organization declared the public health emergency over.

“But the outbreak is not over. We need to remain alert and continue with prevention efforts,” said Dr. Christopher Braden, head of the CDC’s response to the Mpox outbreak, at a press briefing Thursday.

More than 1.2 million doses of the vaccine have been given in the US in the last 12 months. But the number of vaccinations has been falling since last summer, and, according to the CDC, only 23% of people across the country considered at risk have received both doses of vaccine. And there are large geographic, racial, and ethnic disparities in immunization coverage.

It is also clear that the vaccine is not a silver bullet. In a newly reported cluster of cases in Chicago, many of the patients were fully vaccinated.

The Chicago Department of Health and the CDC are investigating this group, which now includes 21 people, all of whom had mild symptoms, Demetre Daskalakis, White House deputy coordinator of the national MPOX response, said at the Thursday press conference. fair.

“What we do know, however, is that vaccination reduces the likelihood that people will contract and spread Mpox. More importantly, even if it does not eliminate the risk of infection, it reduces the likelihood that patients will become seriously ill, be hospitalized or die,” he said.

Manufactured by a small Danish company, Jynneos is the safer of the two Mpox vaccines available. It was initially designed to be given as two doses, both given as a subcutaneous injection 28 days apart.

But as stocks of the vaccine were limited, authorities deviated from the prescribed procedure.

Some started giving just a single dose of the vaccine, which some studies had suggested could already provide considerable protection.

However, last August, federal authorities gave emergency authorization for intradermal dosing to help extend the reach of the limited supply of vaccines.

But there is little evidence so far about the effectiveness of these strategies, which have been based largely on research findings rather than actual patient experience.

Mpox cases could increase in the coming weeks “when people gather at festivals and other events,” the CDC warned. Sanitarians and authorities are recommending that people at risk get vaccinated before the start of LGBTQ pride events, which will start in June.

“To me, the most pressing message would be, ‘If you haven’t had a dose, do it now, because you have to wait four weeks before you can get a second dose,'” said Jacqueline L. Gerhart, chief medical officer of Epic Research and one of the principal investigators of the study published in the New England Journal of Medicine.

Daskalakis said that there are new studies being done on the vaccine, including to investigate the permanence of its effect over time.

With reporting by Sharon Otterman