Virus-like particles were produced in insect cells containing either the L1 and L2 capsid proteins of bovine papillomavirus type 4 (BPV-4) or only the L1 protein. Both preparations of VLPs proved to be extremely effective prophylactic vaccines. Thirteen of 15 calves immunised with either L1-L2 VLPs or L1-VLPs were refractory to experimental challenge with high doses of BPV-4 and did not develop papillomas, while 9 of 10 control animals developed multiple oral papillomas. VLPs were not efficient as therapeutic vaccine in calves with established papillomas, although VLP-vaccinated animals appeared to undergo tumour regression more rapidly than nonvaccinated control animals. Antibody responses in VLP-vaccinated calves were associated with prevention of disease but not with regression of papillomas. Thus prophylactic VLP vaccination is effective in preventing disease in this model of mucosal papillomavirus infection. VLPs and native virus share at least some conformational epitopes, as shown by the cross-reactivity of their antibodies.

We have determined that three type-specific and conformationally dependent monoclonal antibodies, H16.E70, H16.U4, and H16.V5, neutralize pseudotype human papillomavirus type 16 (HPV16) virions in vitro. H16.U4 and H16.V5 neutralized pseudotype virions derived from the German HPV16 variant 114K and the Zairian variant Z-1194 with equal efficiency. In contrast, neutralization of Z-1194 pseudotype virions by H16.E70 was two orders of magnitude weaker than neutralization of 114K pseudotype virions. This difference correlated with enzyme-linked immunosorbent assay reactivity of H16.E70 to L1 virus-like particles of the two variants. A substitution at residue 282 of L1 was responsible for this differential reactivity, suggesting that this residue constitutes part of the H16.E70 epitope.

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SUMMARYA total of 284 Lancashire police officers each with a minimum of 5 years experience was tested for evidence of hepatitis B infection. None was hepatitis B surface antigen positive (HBsAg). Three were positive for both antibody to hepatitis B core antigen (anti-HBc) and HBsAg (anti-HBs). Five were positive for anti-HBc alone. Thus the overall prevalence was 2-8 % which is within the range reported for blood donors in the UK. There was no association with working in the drug squad or custody office but there was a higher prevalence in those who had worked in the scene-of-crime's squad. However, the numbers were small, and of this group of 28 officers, 2 of the 3 with detectable hepatitis B markers were positive for anti-HBc alone. Therefore for police officers in mixed rural/urban areas of the UK, routine administration of hepatitis B vaccine is not justified although special consideration should be given to those working in selected groups. Further studies are required to ascertain whether there may be an increased risk for police officers working in conurbations.

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