An immunosuppressed Israeli, who lived with a vaccinee, is reported to have fallen seriously ill.
Meanwhile, three coincidental deaths among elderly vaccinees at a Pittsburgh clinic forced a suspension in 10 states.
The CDC indicated that it was aware of four similar cases in the preceding 12 months of vaccinia infection after sexual contact with a recent military vaccinee.
The smallpox vaccine is considered one of the most toxic, causing life-threatening complications in 15 of every million vaccinees, of whom one or two might die.
Vaccinees were healthcare workers in emergency departments, intensive care units, anesthesiologists, and health care workers in other settings who would be crucial first-line responders in the event of a bioterrorist attack using smallpox.
Gina Mootrey, CDC medical epidemiologist and VAERS project officer, said that while only a limited number of adverse events are mandated for reporting by vaccine providers and manufacturers, " we encourage the reporting of any event felt to be clinically significant either by the parent of the vaccinee or healthcare provider,"
WI-38, or new diploid cell strains, is used today for the manufacture of most human virus vaccines produced throughout the world including those for poliomyelitis, rubella, rubeola, varicella, mumps, rabies, adenoviruses and hepatitis A . Over one billion vaccinees have received vaccines produced on WI-38 or foreign version of Hayflick's original WI-38.