Approximately 50% of the US population received smallpox vaccinations before routine immunization ceased in 1972 for civilians and in 1990 for military personnel. Several studies have shown long-term immunity after smallpox vaccination, but skepticism remains as to whether this will translate into full protection against the onset of orthopoxvirus-induced disease. The US monkeypox outbreak of 2003 provided the opportunity to examine this issue. Using independent and internally validated diagnostic approaches with >or=95% sensitivity and >or=90% specificity for detecting clinical monkeypox infection, we identified three previously unreported cases of monkeypox in preimmune individuals at 13, 29 and 48 years after smallpox vaccination. These individuals were unaware that they had been infected because they were spared any recognizable disease symptoms. Together, this shows that the US monkeypox outbreak was larger than previously realized and, more importantly, shows that cross-protective antiviral immunity against West African monkeypox can potentially be maintained for decades after smallpox vaccination.

Oral fluid samples were compared with serum samples as a specimen source for hepatitis A, B, and C virus markers. Oral fluid was obtained with a treated absorbent pad and tested by using existing commercial enzyme immunoassays with only minor modifications. Compared with serum sampling the sensitivity and specificity of oral sampling were 100% (51 of 51 samples) and 98% (46 of 47 samples) for hepatitis A virus immunoglobulin M, 100% (29 of 29 samples) and 100% (29 of 29 samples) for hepatitis B virus surface antigen, and 100% (13 of 13 samples) and 100% (13 of 13 samples) for hepatitis C virus antibody, respectively. The decline of hepatitis A virus immunoglobulin M in oral samples was parallel to, though somewhat more rapid than, that of hepatitis A virus immunoglobulin M in serum samples. It is proposed that oral sampling represents a safer and more convenient procedure for reliable hepatitis virus testing than blood sampling and that it has wide application in patient and outbreak management.

CD46 (membrane cofactor protein), a complement-regulatory protein that participates in innate and acquired immunity, also serves as a receptor for viral and bacterial pathogens. CD46 isoforms terminate in one of two cytoplasmic tails, Cyt1 or Cyt2, which differ in signaling and trafficking properties. Dissecting the functions of the two cytoplasmic tails in these cellular processes has been hampered by the absence of specific reagents. Here we report the construction of Cyt1-and Cyt2-specific monoclonal antibodies (MAbs). These MAbs recognize unique epitopes within the tails and can be used for immunofluorescence microscopy, immunoblotting, and immunoprecipitation. Studies of Neisseria gonorrhoeae-infected cells with the CD46 tail MAbs demonstrate the differential recruitment of Cyt1 and Cyt2 to the cortical plaque.

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