The World Health Organization said on Wednesday that the monkeypox vaccine is not a “magic bullet”, with the health body beginning to receive breakthrough case reports after people received the vaccine.
“The fact that we are starting to see breakthrough cases is also very important information because it tells us that the vaccine is not 100% effective in a given circumstance, whether in prevention or post-exposure,” said said Rosamund Lewis, technical officer of the WHO. lead for monkeypox.
“We knew from the start that this vaccine would not be a miracle solution, that it would not meet all the expectations placed on it.”
The only approved monkeypox vaccine comes from developer Bavarian Nordic and is used both as a preventive vaccine and to protect people recently exposed to the virus. Monkeypox, which is spread by close physical contact, was declared a public health emergency of international concern last month by the WHO.
There are few data on the effectiveness of the vaccine, and what is available has been derived from animal studies. The main study used to indicate effectiveness dates back to the 1980s and involved a different type of smallpox vaccine – potentially more potent than the safer vaccines that have been developed since. This study showed 85% protection against monkeypox.
Lewis said groundbreaking new case reports have made it clear that the vaccine will not prevent all cases of monkeypox. Other interventions remain vital, including reducing the number of sexual partners in the highest-risk groups and the time it takes for the vaccine to generate a maximum immune response, usually two weeks after the second dose.
The WHO has called for the establishment of international studies during this global epidemic to generate the data on the effectiveness of the vaccine which is currently lacking.