The study of human monkeypox disease in 2022 using the epidemic models: herd immunity and the basic reproduction number case

As of May 2022, a new outbreak of the human monkeypox (MPOX) disease appeared in multiple countries, where the 2022 human MPOX disease spread to more than 109 cases, excluding the suspected cases up to the end of 2022. The deaths of the 2022 human MPOX exceeded 200 cases up to the same date. The human MPOX is not a new disease, this disease was once endemic in some countries on the African continent. Despite this, this disease began to spread in a number of countries around the world in 2022. The first case of the 2022 human MPOX was recorded in the United Kingdom in May. After that date, this disease began to become a pandemic in a number of other countries, such as the United States, Spain, and Brazil. The 2022 human MPOX is a type of viral disease caused by a viral virus, the MPOX virus, and this virus causes rashes and lesions over the skin of the patient, as well as in the mouth of the patient. Multiple effective indicators are employed for the study of the 2022 of the human MPOX, such as the herd immunity of the human MPOX (HIhMPOX), the basic reproduction number of the human MPOX (BRNhMPOX), and the infection period of the human MPOX. This study focuses on the study of the herd immunity of, and the basic reproduction number of the 2022 outbreak of human MPOX in multiple countries around the world. This study employed the semianalytical method of the Susceptible compartment S, Infectious compartment I, Recovered compartment R (SIR) pandemic model including the mortality for the study of the herd immunity, and the basic reproduction number of the 2022 human MPOX disease. It is found that the average value of the herd immunity for the human MPOX disease in 2022 equals to 0.2194, that is, 21.94% for multiple countries, and equals to 35.52% for the United States, and 30.99% for Spain. Also, it is found that the average value of the basic reproduction number of the 2022 human MPOX disease equals to 1.2810 for multiple countries. It is concluded from these values that 21.94% of the total susceptible population has to be immunized in an effective way to prevent the spreading of the disease. Also, based on the previous values, it is concluded that the status of the 2022 MPOX disease is spreading as a pandemic.