Explore the vast range of titles available.

The Oka varicella vaccine strain remains neurovirulent and can establish lifelong latent infection, raising safety concerns about vaccine-related herpes zoster. In this study, we aimed to evaluate the immunogenicity and safety of a skin-attenuated and neuro-attenuated varicella vaccine candidate (v7D vaccine). We did this randomised, double-blind, controlled, phase 2a clinical trial in Jiangsu, China. Healthy children aged 3–12 years with no history of varicella infection or vaccination were enrolled and randomly assigned (1:1:1:1) to receive a single subcutaneous injection of the v7D vaccine at 3·3 log10 plaque forming units (PFU; low-dose v7D group), 3·9 log10 PFU (medium-dose v7D group), and 4·2 log10 PFU (high-dose v7D group), or the positive control varicella vaccine (vOka vaccine group). All the participants, laboratory personnel, and investigators other than the vaccine preparation and management staff were masked to the vaccine allocation. The primary outcome was assessment of the geometric mean titres (GMTs) and seroconversion rates of anti-varicella zoster virus immunoglobulin G (IgG) induced by different dose groups of v7D vaccine at 0, 42, 60, and 90 days after vaccination in the per-protocol set for humoral immune response analysis. Safety was a secondary outcome, focusing on adverse events within 42 days post-vaccination, and serious adverse events within 6 months after vaccination. This study was registered on Chinese Clinical Trial Registry, ChiCTR2000034434. On Aug 18–21, 2020, 842 eligible volunteers were enrolled and randomly assigned treatment. After three participants withdrew, 839 received a low dose (n=211), middle dose (n=210), or high dose (n=210) of v7D vaccine, or the vOka vaccine (n=208). In the per-protocol set for humoral immune response analysis, the anti-varicella zoster virus IgG antibody response was highest at day 90. At day 90, the seroconversion rates of the low-dose, medium-dose, and high-dose groups of v7D vaccine and the positive control vOka vaccine group were 100·0% (95% CI 95·8–100·0; 87 of 87 participants), 98·9% (93·8–100·0; 87 of 88 participants), 97·8% (92·4–99·7; 91 of 93 participants), and 96·4% (89·8–99·2; 80 of 83 participants), respectively; the GMTs corresponded to values of 30·8 (95% CI 26·2–36·0), 31·3 (26·7–36·6), 28·2 (23·9–33·2), and 38·5 (31·7–46·7). The v7D vaccine, at low dose and medium dose, elicited a humoral immune response similar to that of the vOka vaccine. However, the high-dose v7D vaccine induced a marginally lower GMT compared with the vOka vaccine at day 90 (p=0·027). In the per-protocol set, the three dose groups of the v7D vaccine induced a similar humoral immune response at each timepoint, with no statistically significant differences. The incidence of adverse reactions in the low-dose, medium-dose, and high-dose groups of v7D vaccine was significantly lower than that in the vOka vaccine group (17% [35 of 211 participants], 20% [41 of 210 participants], and 13% [27 of 210 participants] vs 24% [50 of 208 participants], respectively; p=0·025), especially local adverse reactions (10% [22 of 211 participants], 14% [30 of 210 participants] and 9% [18 of 210 participants] vs 18% [38 of 208 participants], respectively; p=0·016). None of the serious adverse events were vaccine related. The three dose groups of the candidate v7D vaccine exhibit similar humoral immunogenicity to the vOka vaccine and are well tolerated. These findings encourage further investigations on two-dose vaccination schedules, efficacy, and the potential safety benefit of v7D vaccine in the future. The National Natural Science Foundation of China, CAMS Innovation Fund for Medical Sciences, the Fundamental Research Funds for the Central Universities, and Beijing Wantai. For the Chinese translation of the abstract see Supplementary Materials section.

Bertie's sister has chickenpox and Bertie thinks that if he can catch it he will not have to go to school and admit he did not do his homework--and that is just the first problem that Bertie faces in this trio of stories.

When Nazboo comes down with dragon pox, Leah, Shimmer, and Shine volunteer to get a dragon pepper to help the sick dragon get better.

•The study compared efficacy of one or two doses of varicella vaccines versus a control group.•We present efficacy results up to six years post-vaccination.•Efficacy of two MMRV doses or one varicella vaccine dose persists six years post-vaccination.•Two doses of MMRV were highly efficacious against varicella of any severity.•One dose of varicella vaccine was highly efficacious against moderate and severe disease. This phase III B follow-up of an initial multicenter study (NCT00226499) will evaluate the ten-year efficacy of two doses of the combined measles-mumps-rubella-varicella vaccine (MMRV) and one dose of the live attenuated varicella vaccine (V) versus a measles-mumps-rubella control group (MMR) for the prevention of clinical varicella disease. Here we present efficacy results for six years post-vaccination. In phase A of the study, healthy children aged 12–22 months from ten European countries were randomized (3:3:1) and received either two doses of MMRV, or one dose of combined MMR and one dose of monovalent varicella vaccine (MMR+V), or two doses of the MMR vaccine (control), 42 days apart. Vaccine efficacy against all and against moderate or severe varicella (confirmed by detection of viral DNA or epidemiological link) was assessed from six weeks up to six years post-dose 2 for the MMRV and MMR+V groups, and was calculated with 95% confidence intervals (CI). The severity of varicella was calculated using the modified Vázquez scale (mild ≤ 7; moderately severe = 8–15; severe ≥ 16). Herpes zoster cases were also recorded. 5289 children (MMRV = 2279, mean age = 14.2, standard deviation [SD] = 2.5; MMR+V = 2266, mean age = 14.2, SD = 2.4; MMR = 744, mean age = 14.2, SD = 2.5 months) were included in the efficacy cohort. 815 varicella cases were confirmed. Efficacy of two doses of MMRV against all and against moderate or severe varicella was 95.0% (95% CI: 93.6–96.2) and 99.0% (95% CI: 97.7–99.6), respectively. Efficacy of one dose of varicella vaccine against all and against moderate or severe varicella was 67.0% (95% CI: 61.8–71.4) and 90.3% (95% CI: 86.9–92.8), respectively. There were four confirmed herpes zoster cases (MMR+V = 2, MMR = 2), all were mild and three tested positive for the wild-type virus. Two doses of the MMRV vaccine and one dose of the varicella vaccine remain efficacious through six years post-vaccination.

Background. Because of ongoing outbreaks of varicella, a second dose of varicella vaccine was added to the routine immunization schedule for children in June 2006 by the Centers for Disease Control and Prevention. Methods. We assessed the effectiveness of 2 doses of varicella vaccine in a case-control study by identifying children ≥4 years of age with varicella confirmed by polymerase chain reaction assay and up to 2 controls matched by age and pediatric practice. Effectiveness was calculated using exact conditional logistic regression. Results. From July 2006 to January 2010, of the 71 case subjects and 140 matched controls enrolled, no cases (0%) vs 22 controls (15.7%) had received 2 doses of varicella vaccine, 66 cases (93.0%) vs 117 controls (83.6%) had received 1 dose, and 5 cases (7.0%) vs 1 control (0.7%) did not receive varicella vaccine (P < .001). The effectiveness of 2 doses of the vaccine was 98.3% (95% confidence level [CI]: 83.5%–100%; P < .001). The matched odds ratio for 2 doses vs 1 dose of the vaccine was 0.053 (95% CI: 0.002–0.320; P < .001). Conclusion. The effectiveness of 2 doses of varicella vaccine in the first 2.5 years after recommendation of a routine second dose of the vaccine for children is excellent. Odds of developing varicella were 95% lower for children who received 2 doses compared with 1 dose of varicella vaccine.

In 2013, Turkey introduced one-dose universal varicella vaccination (UVV) at 12 months of age. Inclusion of a second dose is being considered. We developed a dynamic transmission model to evaluate three vaccination strategies: single dose at 12 months (1D) or second dose at either 18 months (2D-short) or 6 years of age (2D-long). Costs and utilization were age-stratified and separated into inpatient and outpatient costs for varicella and herpes zoster (HZ). We ran the model including and excluding HZ-related costs and impact of exogenous boosting. Five years post-introduction of UVV (1D), the projected varicella incidence rate decreases from 1,674 cases pre-vaccine to 80 cases/100,000 person-years. By 25 years, varicella incidence equilibrates at 39, 12, and 16 cases/100,000 person-years for 1D, 2D-short, and 2D-long strategies, respectively, using a highly effective vaccine. With or without including exogenous boosting impact and/or HZ-related costs and health benefits, the 1D strategy is least costly, but 2-dose strategies are cost-effective considering a willingness-to-pay threshold equivalent to the gross domestic product. The model predicted a modest increase in HZ burden during the first 20-30 years, after which time HZ incidence equilibrates at a lower rate than pre-vaccine. Our findings support adding a second varicella vaccine dose in Turkey, as doing so is highly cost-effective across a wide range of assumptions regarding the burden associated with varicella and HZ disease.

Two distinct diseases are attributable to the varicella zoster virus, varicella (chickenpox) and zoster (shingles). This study assesses the impact and cost-effectiveness of a childhood varicella vaccination program in England. We use an age-structured dynamic transmission model and a health economic decision tree. The model incorporates recent data on varicella and zoster epidemiology, including the effects of exogenous boosting on zoster incidence. By simulating various vaccination strategies, including routine and catch-up programs, the study evaluates the potential reduction in varicella and zoster cases due to vaccination and the associated vaccine cost-effectiveness (from the NHS perspective). We find that a two-dose varicella vaccination program could significantly reduce varicella incidence, potentially achieving near-elimination if high coverage rates are maintained. However, the model also predicts a temporary increase in zoster incidence due to reduced natural boosting from varicella exposure; this is partly mitigated by the current zoster vaccination program and the effect is much less substantial than previously estimated. Cost-effectiveness analyses reveal that all vaccination strategies modelled are cost-effective at typical thresholds, with the routine vaccination scenario being the most economically advantageous. Sensitivity analyses demonstrate that vaccine price and varicella treatment costs are the primary drivers of cost-effectiveness. The study supports the introduction of a childhood varicella vaccination program in England, which offers substantial health benefits and is highly likely to be cost-effective. •The study models the impact and cost-effectiveness of universal varicella vaccination in England.•A two-dose program could significantly reduce varicella cases and achieve near elimination with high coverage.•The program may cause a temporary increase in zoster cases, but this to a lesser extent than previously believed.•All vaccination strategies examined were found to be cost-effective, with routine vaccination being the most beneficial.•Cost-effectiveness depends primarily on vaccine prices and varicella treatment costs.

Summary Background Rates of varicella have decreased substantially in countries implementing routine varicella vaccination. Immunisation is possible with monovalent varicella vaccine or a combined measles-mumps-rubella-varicella vaccine (MMRV). We assessed protection against varicella in naive children administered one dose of varicella vaccine or two doses of MMRV. Methods This study was done in ten European countries with endemic varicella. Healthy children aged 12–22 months were randomised (3:3:1 ratio, by computer-generated randomisation list, with block size seven) to receive 42 days apart (1) two doses of MMRV (MMRV group), or (2) MMR at dose one and monovalent varicella vaccine at dose two (MMR+V group), or (3) two doses of MMR (MMR group; control). Participants and their parents or guardians, individuals involved in assessment of any outcome, and sponsor staff involved in review or analysis of data were masked to treatment assignment. The primary efficacy endpoint was occurrence of confirmed varicella (by detection of varicella zoster virus DNA or epidemiological link) from 42 days after the second vaccine dose to the end of the first phase of the trial. Cases were graded for severity. Efficacy analyses were per protocol. Safety analyses included all participants who received at least one vaccine dose. This trial is registered with ClinicalTrials.gov , number NCT00226499. Findings Between Sept 1, 2005, and May 10, 2006, 5803 children (mean age 14·2 months, SD 2·5) were vaccinated. In the efficacy cohort of 5285 children, the mean duration of follow-up in the MMRV group was 36 months (SD 8·8), in the MMR+V group was 36 months (8·5) and in the MMR group was 35 months (8·9). Varicella cases were confirmed for 37 participants in the MMRV group (two moderate to severe), 243 in the MMR+V group, and 201 in the MMR group. Second cases occurred for three participants (all in the MMR+V group). Varicella cases were moderate to severe for two participants in the MMRV group, 37 in the MMR+V group (one being a second case that followed a mild first case); and 117 in the MMR group. Efficacy of two-dose MMRV against all varicella was 94·9% (97·5% CI 92·4–96·6), and against moderate to severe varicella was 99·5% (97·5–99·9). Efficacy of one-dose varicella vaccine against all varicella was 65·4% (57·2–72·1), and against moderate to severe varicella (post hoc) was 90·7% (85·9–93·9). The most common adverse event in all groups was injection-site redness (up to 25% of participants). Within 15 days after dose one, 57·4% (95% CI 53·9–60·9) of participants in the MMRV group reported fever of 38°C or more, by contrast with 44·5% (41·0–48·1) with MMR+V, and 39·8% (33·8–46·1) with MMR. Eight serious adverse events were deemed related to vaccination (three MMRV, four MMR+V, one MMR). All resolved within the study period. Interpretation These results support the implementation of two-dose varicella vaccination on a short course, to ensure optimum protection from all forms of varicella disease. Funding GlaxoSmithKline Vaccines.