Anti-Varicella zoster virus Monoclonal antibody, Clone 7D9

Background: Varicella-zoster virus (VZV) infection in children is an important public health problem in China. We performed the current study to explore the seroprevalence of VZV infection in Chinese children in order to provide more information for improvement of varicella vaccination in China. Methods: Three thousand fourteen children were recruited from Chinese kindergarten students aged from four to sixyears. Anti-VZV IgG and IgM were assayed using enzyme-linked immunosorbent assay. Both ORF22 and ORF62 of VZV were amplified, sequenced, and analyzed by nested PCR. Results: Among 3014 children, 43.9% of boys and 46.3% of girls were vaccinated with varicella vaccine, respectively. The seroprevalence of anti-VZV IgG was 54.4% in the children with varicella vaccination, which was significantly higher than those in unvaccinated children (49.2%) (chi(2)=8.206, P=0.004). Among of the vaccinated children, the detection rates of VZV IgG antibody increased with age, with 49.4, 50.9 and 58.9% in 4, 5 and 6-year groups, respectively (Trend chi(2)=17.202, P=0.002). However, there was no difference in anti-VZV IgG detection rates among those unvaccinated children in different age groups (Trend chi(2)=8.681, P=0.070). In addition, 13 boys and 13 girls were positive for anti-VZV IgM, respectively. Among of them, eight children (0.6%) have received varicella vaccination, which was similar to those in unvaccinated children (1.1%). However, only one ORF22 sequence was isolated from an unvaccinated 5-year boy. Compared to the reference VZV sequences, the nucleotide homology was estimated to be 99.7% with genotype J. Conclusions: Our study indicated that about half of Chinese children aged four to sixyears have a high risk of VZV infection. It should be helpful for the evaluation on the necessity of varicella immunization in China.

Introduction The prevalence of herpes zoster (HZ) is high in patients with rheumatologic diseases. The incidence in patients with rheumatoid arthritis (RA) is at least twice as high as in healthy people. Nevertheless, little is known about humoral immunity against varicella zoster virus (VZV), in particular in patients with RA. We, therefore, aimed to retrospectively compare VZV antibody concentrations in a collective of patients with RA in a German outpatient clinic with age- and sex-matched controls without RA. Methods We included n = 247 patients with RA from one single university centre as well as n = 250 age- and sex-matched controls from the in-house routine in this retrospective analysis. The concentration of VZV IgG antibody concentration was either available from the records or was measured using an enzyme-linked immunosorbent assay (ELISA). Additionally, avidity for specific IgG was analysed for some of the samples. The antibody concentrations have been compared between the two groups. Moreover, a consecutive subgroup analysis after stratification by age was performed. Results A total of 68.4% (n = 169) of the included patients were treated with conventional synthetic DMARDs, either as monotherapy or in combination. Biological originator DMARDs were used in 45.8% (n = 113) of the patients, with the majority (85%, n = 96) of them being on tumour necrosis factor (TNF)-inhibiting agents. As the main result of this study, antibody titres for VZV were found to be significantly lower in RA patients compared with healthy controls (p < 0.0001). The observed difference was most pronounced for the older patients being in the sixth and seventh decade. Antibody avidity was high in both groups with a significantly higher avidity among the controls (p = 0.0006). Conclusions A possible explanation for the low VZV antibody concentration in RA patients might be premature immunosenescence, which most likely also effects the B cell compartment and humoral immunity. This thesis is emphasised by the significantly higher antibody avidity among the controls. The data also suggest that the increased HZ risk is a consequence of a poor humoral immunity. The available HZ vaccinations should contribute to decreasing the elevated HZ risk in RA patients.