LC16m8, a highly attenuated vaccinia virus vaccine lacking expression of the membrane protein B5R, protects monkeys from monkeypox.
The potential threat of smallpox as a bioweapon has led to the production and stockpiling of smallpox vaccine in some countries. Human monkeypox, a rare but important viral zoonosis endemic to central and western Africa, has recently emerged in the United States. Thus, even though smallpox has been eradicated, a vaccinia virus vaccine that can induce protective immunity against smallpox and monkeypox is still invaluable. The ability of the highly attenuated vaccinia virus vaccine strain LC16m8, with a mutation in the important immunogenic membrane protein B5R, to induce protective immunity against monkeypox in nonhuman primates was evaluated in comparison with the parental Lister strain. Monkeys were immunized with LC16m8 or Lister and then infected intranasally or subcutaneously with monkeypox virus strain Liberia or Zr-599, respectively. Immunized monkeys showed no symptoms of monkeypox in the intranasal-inoculation model, while nonimmunized controls showed typical symptoms. In the subcutaneous-inoculation model, monkeys immunized with LC16m8 showed no symptoms of monkeypox except for a mild ulcer at the site of monkeypox virus inoculation, and those immunized with Lister showed no symptoms of monkeypox, while nonimmunized controls showed lethal and typical symptoms. These results indicate that LC16m8 prevents lethal monkeypox in monkeys, and they suggest that LC16m8 may induce protective immunity against smallpox.
Saijo
Masayuki
M
Special Pathogens Laboratory, Department of Virology 1, National Institute of Infectious Diseases, 4-7-1 Gakuen, Musashimurayama, Tokyo 208-0011, Japan. msaijo@nih.go.jp
Ami
Yasushi
Y
Suzaki
Yuriko
Y
Nagata
Noriyo
N
Iwata
Naoko
N
Hasegawa
Hideki
H
Ogata
Momoko
M
Fukushi
Shuetsu
S
Mizutani
Tetsuya
T
Sata
Tetsutaro
T
Kurata
Takeshi
T
Kurane
Ichiro
I
Morikawa
Shigeru
S
D000818:Animals; D000882:Haplorhini; D008562:Membrane Glycoproteins / Q000276:immunology; D045908:Mpox, Monkeypox / Q000517:prevention & control*; D008993:Monkeypox virus / Q000187:drug effects*; D012900:Smallpox Vaccine / Q000008:administration & dosage* / Q000276:immunology; D014613:Vaccines, Attenuated / Q000008:administration & dosage / Q000276:immunology; D014616:Vaccinia virus / Q000276:immunology*; D014759:Viral Envelope Proteins / Q000276:immunology
D008562:Membrane Glycoproteins; D012900:Smallpox Vaccine; D014613:Vaccines, Attenuated; D014759:Viral Envelope Proteins; C074512:42kDa protein, Vaccinia virus