A recent report from the United States describes cases where people who had received two doses of the JYNNEOS monkeypox vaccine later became infected with the monkeypox virus. The report does not specify who these people were, how many cases there were, or how much time passed between vaccination and infection. It simply confirms that such infections have occurred.
This is not a formal research study. It is a report of observations, so it lacks critical details. We do not know if the infections were mild or severe, or if the people had other health conditions. The report does not compare these cases to people who were unvaccinated, so we cannot tell if the vaccine reduced the severity of illness.
Because this is just an initial report, it is too early to draw any conclusions about the vaccine's protection. Vaccines are rarely 100% effective, and 'breakthrough' infections can happen. This information is a reminder that vaccination is one layer of protection, but it may not prevent all infections. Readers should view this as an early signal that health officials are monitoring, not as proof the vaccine doesn't work.