Monkeypox virus and preventive vaccine
Monkeypox virus and preventive vaccine
Monkeypox is a viral zoonosis. The symptoms in humans are similar to those seen in smallpox patients in the past. However, since the eradication of smallpox in the world in 1980, smallpox has disappeared, and monkeypox is still distributed in parts of Africa.
Monkeypox occurs in monkeys in rainforests in central and western Africa. It can also infect other animals, and occasionally human beings. The clinical manifestation is similar to smallpox, but the condition is mild. This disease is caused by monkeypox virus, which belongs to a virus group that includes smallpox virus and the virus and cowpox virus used in smallpox vaccine, but it needs to be identified with smallpox and varicella. The virus can be transmitted from animals to people through direct close contact, and can also be transmitted from person to person. The main routes of infection include blood and body fluids. However, monkeypox is far less infectious than smallpox virus.
The monkeypox epidemic in 2022 was first discovered in the UK on May 7, 2022 local time [5]. On May 20 local time, with more than 100 confirmed and suspected monkeypox cases in Europe, the World Health Organization confirmed to hold an emergency meeting on monkeypox [6].
On May 29, 2022 local time, WHO issued a disease information bulletin and assessed the global public health risk of monkeypox as medium. [12]
According to the Russian satellite news agency on June 24, 2022, WHO Director General Tan Desai said that the number of confirmed cases of monkeypox in the world has exceeded 3200. [17]
At 15pm local time on July 23, 2022, the World Health Organization held a press conference in Geneva. Director General Tan Desai announced that the monkeypox epidemic would be listed as a "public health emergency of international concern". [20]
Preventive vaccine
Smallpox vaccine
According to WHO, observational studies show that the effectiveness of smallpox vaccination in the prevention of monkeypox is about 85%, and vaccination of smallpox vaccine before may reduce the severity of the disease caused by monkeypox virus infection. At present, the state arranges Sinopharm Beijing Institute of Biological Products to produce a certain amount of "Temple of Heaven Strain" smallpox vaccine as a reserve every year. [10]
JYNNEOS
Because orthopoxvirus immune response can provide cross protection, smallpox and monkeypox vaccines are mainly designed based on vaccinia virus. In 2019, a modified attenuated non replicating vaccinia virus (Ankara strain) vaccine JYNNEOS (also known as Immune or Imvanex) was approved for the prevention of monkeypox. The vaccine was developed by Bavarian Nordic Company in Denmark. Two doses of the vaccine, in addition to being vaccinated before exposure to the virus for prevention, may also help prevent the disease or reduce its severity after exposure. CDC of the United States suggests that vaccination should be carried out within 4 days after exposure to the virus to prevent the onset of the disease, and vaccination within 4-14 days after exposure may reduce the symptoms of the disease. [10]