Experts believe immunity to monkeypox after infection or vaccination is lifelong, The New York Times reported Sept. 8.
This is based on what scientists know about other infections caused by orthopoxviruses, such as smallpox. Research has shown immune cells that combat infected cells can still be found in people's blood up to 83 years after an initial smallpox infection. Similar results have been found when looking at antibodies that neutralize the smallpox virus, the Times reports.
Experts said lifelong immunity is the case for most viruses that mutate slowly, such as those that cause measles or mumps. Viruses that cause respiratory illnesses, however, such as the flu and COVID-19, adapt quickly, making reinfection much more common.
Three more monkeypox outbreak updates:
1. The CDC has confirmed 21,985 cases in the U.S. as of Sept. 12. Newly reported cases over the weekend fell below 100 for the first time in two months.
2. Los Angeles health officials have confirmed monkeypox as the cause of death in a resident. The county's health department in a Sept. 12 statement said the individual was "severely immunocompromised and had been hospitalized." No other details about the patient were released. This marks the nation's first confirmed fatality from the disease. Last week, Los Angeles health officials said they were investigating whether monkeypox contributed to the patient's death and were waiting for autopsy results to release further information. In Texas, health officials in late August confirmed the death of a resident who tested positive for monkeypox and had other "various severe illnesses." Texas health officials have not yet determined what role, if any, the disease had in the individual's death.
3. The U.S. has launched a phase 3 clinical trial on Tpoxx, the antiviral being used to treat monkeypox. The trial aims to enroll 500 people. If proven effective, access could be significantly expanded.