Abstract: A blind rivet is injection molden from plastic material. It comprises a female member molded about a male member. The female member is comprised of a flexible tubular wall and a flange about the upper end thereof, the wall defining a stepped portion in the axial bore thereof at the upper end and a plurality of elongate perforations about the wall. The male member is comprised of a shank in the axial bore and axially movable in relation to the tubular wall, an enlarged head at one end in intimate contact and engagement with the lower end of the female member, and a head portion at the other end and protruding from the upper end of the female member.

Abstract: A vaccine effective against challenge infections, such as bovine mastitis is prepared from Staphyloccus aureus or Staphylococcus epidermidis strain.