GENEVA, May 30. /TASS/. The fast spread of monkeypox in non-endemic states may be connected to the lack of immunity for this disease in the vast majority of population, because vaccination against smallpox ended back in 20th century, says World Health Organization (WHO) Smallpox Secretariat head Dr. Rosamund Lewis.

She noted that, back in 1980, the WHO declared total elimination of smallpox, which led to end of vaccination against this disease around the world. Meanwhile, a smallpox shot provides efficient protection against monkeypox, because both viruses are members of "one family."

According to Lewis, people had had no effective protection against smallpox via vaccination during the last 40 years, which may partially explain a rather fast spread of monkeypox via close physical contacts. The expert opined that the fast spread may be explained by the fact that people currently have no immunity against smallpox.

Lewis underscored that people who took a smallpox shot, in particular those aged above 50, probably have protection against monkeypox, but this is not definite, because 50 years is a long term for a vaccine effect. She acknowledged that it is unknown if these people have any immunity against monkeypox.

Earlier, the WHO announced that, by May 26, a total of 257 of confirmed and 120 presumed monkeypox cases were registered in 23 countries. Monkeypox is a rare viral disease, mostly transmitted to people from wild animals. The symptoms include fever, headache, muscle ache, back pain, enlargement of lymph nodes, cold and fatigue. The disease may also cause rash on the face or other body parts. According to the WHO the lethality coefficient stands at between 1% and 10%, with most fatalities contributing to younger ages.