Patents by Inventor Elmer R. Pfefferkorn

Elmer R. Pfefferkorn has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Vaccine for immunizing cats against toxoplasma oocyst shedding
    Patent number: 5045313
    Abstract: A new mutant strain vaccine, and a corresponding method of immunization, against Toxoplasma in cats is provided which makes use of a reproductively deficient strain of T.gondii, designated T-263. Bradyzoites in tissue cysts from laboratory animals infected with the mutant were fed to cats, which developed immunity against subsequent T.gondii challenge without concomitant shedding of infectious oocysts. The new vaccine eliminates the need for chemoprophylaxis subsequent to primary infection.
    Type: Grant
    Filed: July 7, 1989
    Date of Patent: September 3, 1991
    Assignees: The University of Kansas, Darmouth College
    Inventors: Jacob K. Frenkel, Elmer R. Pfefferkorn
  • Method for the immunization of animals and men against Toxoplasma gondii _
    Patent number: 4473549
    Abstract: A method for the immunization of mammals (including man) and birds, against Toxoplasma gondii is described which involves subcutaneous administration of a live, low-virulent vaccine comprising a temperature-sensitive mutant of the persistent, virulent RH strain of T. gondii. The vaccine gives immunity against subsequent challenge, but does not persist and does not cause chronic infection of the subject and which therefore cannot result in illness or death in the event that the subject later becomes immunosuppressed.
    Type: Grant
    Filed: July 30, 1982
    Date of Patent: September 25, 1984
    Assignees: The Kansas University Endowment Association, Elmer R. Pfefferkorn
    Inventors: Jacob K. Frenkel, Elmer R. Pfefferkorn