Genome sequences of chicken (low pathogenic avian influenza [LPAI] and highly pathogenic avian influenza [HPAI]) and human isolates from a 2004 outbreak of H7N3 avian influenza in Canada showed a novel insertion in the HA0 cleavage site of the human and HPAI isolate. This insertion likely occurred by recombination between the hemagglutination and matrix genes in the LPAI virus.

We investigated whether there was an association between GBV‐C viremia and the development of non‐Hodgkin lymphoma (NHL) in 553 NHL cases and 438 controls from British Columbia, Canada. Cases were aged 20–79, diagnosed between March 2000 and February 2004, and resident in Greater Vancouver or Victoria. Cases and controls were tested for GBV‐C RNA by RT‐PCR and positive samples were genotyped. Overall, GBV‐C RNA was detected in 4.5% of NHL cases vs. 1.8% of controls [adjusted odds ratio (OR) = 2.72, 95% confidence interval (CI) = 1.22–6.69]. The association between GBV‐C RNA detection and NHL remained even after individuals with a history of prior transfusion, injection drug use and hepatitis C virus sero‐positivity were excluded. GBV‐C viremia showed the strongest association with diffuse large B cell lymphoma (adjusted OR = 5.18, 95% CI = 2.06–13.71). Genotyping was performed on 29/33 GBV‐C RNA positive individuals; genotypes 2a (n = 22); 2b (n = 5) and 3 (n = 2) were identified, consistent with the distribution of genotypes found in North America. This is the largest case‐control study to date associating GBV‐C viremia and NHL risk. As GBV‐C is known to be transmitted through blood products this may have important implications for blood safety.

Human papillomavirus 16 (HPV 16) and HPV 18 antibody responses in a 2-versus 3-dose HPV vaccine (Gardasil) trial were measured by a pseudovirus neutralizing antibody (PsV NAb) assay and by the Merck competitive Luminex immunoassay (cLIA). Eight hundred twenty-four female subjects assigned to three dosing regimens (group 1, 9 to 13 years old; 2 doses, months 0 and 6 [n ‫؍‬ 259]; group 2, 9 to 13 years old; 3 doses, months 0, 2, and 6 [n ‫؍‬ 260]; group 3, 16 to 26 years old; 3 doses, months 0, 2, and 6 [n ‫؍‬ 305]) had postvaccine responses assessed 1 month after the last dose. Of 791 subjects with baseline and 7-month sera, 15 (1.9%) and 9 (1.1%) were baseline seropositive for HPV 16 and HPV 18, respectively. All baseline-seronegative vaccinees seroconverted to both HPV 16 and HPV 18. Mean anti-HPV 16 levels were similar for groups 1 and 2 (for PsV NAb, P ‫؍‬ 0.675; for cLIA, P ‫؍‬ 0.874), and levels for both groups 1 and 2 were approximately 2-fold higher than that for group 3 (for PsV NAb and cLIA, P < 0.001). Mean anti-HPV 18 levels were approximately 1.4-fold lower in group 1 than in group 2 (for PsV, NAb P ‫؍‬ 0.013; for cLIA, P ‫؍‬ 0.001), and levels for both groups 1 and 2 were approximately 2.0-to 2.5-fold higher than that for group 3 (for PsV NAb and cLIA, P < 0.001). Pearson correlation coefficients for the assays were 0.672 for HPV 16 and 0.905 for HPV 18. Most of the discordant results were observed at lower cLIA signals. These results suggest that the PsV NAb assay could be a suitable alternative to cLIA for the measurement of postvaccine antibody responses.

We assessed HPV 16 and 18 antibody responses of female subjects enrolled in a 2- vs. 3-dose quadrivalent HPV (Q-HPV) vaccine trial (ClinicalTrials.gov NCT00501137) using the Merck competitive Luminex (cLIA) and total IgG Luminex (TIgG) immunoassays, and a pseudovirus neutralizing antibody (PsV NAb) assay. Subjects were enrolled in one of three groups: (1) 9-13yr, 2 doses of Q-HPV at 0, 6 months (n=259); (2) 9-13yr, 3 doses at 0, 2, 6 months (n=260); and (3) 16-26yr, 3 doses at 0, 2, 6 months (n=305). Sera were collected from all subjects at baseline, months 7 and 24, and from half the subjects at months 18 and 36. High correlation was observed between all three assays. At month 36, HPV 16 antibodies remained detectable in all subjects by all assays, whereas 86.4%, 99.6% and 100% of subjects respectively were HPV 18 cLIA, TIgG and PsV NAb (partial neutralization endpoint) seropositive. The proportion seropositive for HPV 18 by cLIA at 36 months was not significantly different for 2-dose girls vs. 3-dose adults (85.9% vs. 79.4%; p=0.51), whereas the proportion for 3-dose girls was significantly higher than for 3-dose adults (95.3% vs. 79.4%; p<0.01). The HPV 18 seropositive proportions by the TIgG and PsV NAb (partial neutralization endpoint) assays were the same for all subjects. High baseline HPV 16 and HPV 18 seropositivity was observed for the TIgG assay and it is unclear if all the detected TIgG antibodies are type-specific and/or neutralizing. For the PsV NAb assay, 90% and partial neutralization geometric mean titres were consistently 2-8-fold higher than for 100% neutralization, which enabled detection of HPV 18 NAb in subjects who lost detectable cLIA antibodies over time. We conclude that the PsV NAb assay is more sensitive than the cLIA, and likely more specific than the TIgG assay.