In a recent study published in emerging infectious diseases journal, researchers at the Madigan Army Medical Center evaluated the characteristics of monkeypox infection in a patient who had been vaccinated against smallpox.
In the summer of 2022, the Centers for Disease Control and Prevention (CDC) began an emergency response after an outbreak of monkeypox infection across the United States. In addition, on June 28, 2022, the US Department of Health and Human Services (HHS) announced a vaccination strategy against monkeypox virus that will be implemented across the country.
Research message: Monkeypox vaccination in patient with ACAM2000 smallpox vaccine during the 2022 outbreak. Image Credit: Dotted Yeti / Shutterstock
In this study, the team reported that a patient residing in Washington, USA was infected with monkeypox virus. However, he was successfully vaccinated against smallpox with the ACAM2000 smallpox vaccine eight years ago.
The patient was a 34-year-old male who reported having sex with men. He went to an STD clinic with a four-day history of malaise, fatigue, and headache with a two-day history of four painless lesions of the penis. The patient was evaluated in the local emergency department two days prior to his visit to the clinic. He tested negative for Chlamydia trachomatis, Neisseria gonorrhoeae, and herpes simplex virus. While his structural symptoms showed improvement over the next two days, his penile ulcers developed into white papular lesions.
The patient reported a history of syphilis and N. gonorrhea in 2017 and resolved after treatment. His military health records showed no history of HIV infection or other immunodeficiency conditions. He had previously recommended daily treatment with emtricitabine/tenovir as a precautionary measure before exposure to HIV. However, he stopped this treatment himself a year before seeking medical attention. In the past 90 days, the patient reported having had oral and penetrative anal intercourse with 13 to 14 new partners without any use of condoms. His last sexual encounter was reported 11 days prior to seeking medical attention when he had unprotected anal sexual intercourse with one partner at a local pride event.
Because of his military service, the patient received the ACAM2000 smallpox vaccine in March 2014. Furthermore, he denied any recent travel outside Washington or contact with sick individuals.
The results of the study showed that the patient showed four ulcerated lesions on the penis which developed into a patch on the foreskin. This correction is observed 2 days after the onset of the patient’s structural symptoms. The lesions were painless with no exudate. A sensitive inguinal lymph node was also noted, along with a graft scar on the right deltoid.
The team noted that the patient tested positive for NPV by polymerase chain reaction (PCR). Subsequent testing showed that the Clade II strain caused the infection. However, the patient tested negative for hepatitis C, syphilis, and HIV-1/2 . antigen and the antibody.
The patient required only supportive care with oral acetaminophen administration to treat structural symptoms, which resolved ten days after symptom onset. The rash developed, clustered, and developed into a blister six days after the first onset of the structural symptoms. The lesion developed into an ulcer on day 16 before it dissipated without causing any residual scarring.
Overall, the study showed that while vaccination was essential in preventing infectious disorders, vaccination alone could prove insufficient in providing immunity against monkeypox infection. Therefore, researchers believe that vaccination should be a complement rather than a substitute for public health campaigns that facilitate the reduction of high-risk health behaviors.