Evaluation of antibody kinetics and durability in health subjects vaccinated with inactivated COVID-19 vaccine (CoronaVac): A cross-sectional and cohort study in Zhejiang, China

BackgroundAlthough inactivated COVID-19 vaccines are proven to be safe and effective in the general population, the dynamic response and duration of antibodies after vaccination in the real world should be further assessed. MethodsWe enrolled 1067 volunteers who had been vaccinated with one or two doses of CoronaVac in Zhejiang Province, China. Another 90 healthy adults without previous vaccinations were recruited and vaccinated with three doses of CoronaVac, 28 days and 6 months apart. Serum samples were collected from multiple timepoints and analyzed for specific IgM/IgG and neutralizing antibodies (NAbs) for immunogenicity evaluation. Antibody responses to the Delta and Omicron variants were measured by pseudovirus-based neutralization tests. ResultsOur results revealed that binding antibody IgM peaked 14-28 days after one dose of CoronaVac, while IgG and NAbs peaked approximately 1 month after the second dose then declined slightly over time. Antibody responses had waned by month 6 after vaccination and became undetectable in the majority of individuals at 12 months. Levels of NAbs to live SARS-CoV-2 were correlated with anti-SARS-CoV-2 IgG and NAbs to pseudovirus, but not IgM. Homologous booster around 6 months after primary vaccination activated anamnestic immunity and raised NAbs 25.5-fold. The NAb inhibition rate subsequently rose to 36.0% for Delta (p=0.03) and 4.3% for Omicron (p=0.004), and the response rate for Omicron rose from 7.9% (7/89) to 17.8% (16/90). ConclusionsTwo doses of CoronaVac vaccine resulted in limited protection over a short duration. The homologous booster slightly increased antibody responses to the Delta and Omicron variants; therefore, the optimization of booster procedures is vital. FundingKey Research and Development Program of Zhejiang Province; Key Program of Health Commission of Zhejiang Province/ Science Foundation of National Health Commission; Major Program of Zhejiang Municipal Natural Science Foundation.

Immunogenicity and safety of a SARS-CoV-2 inactivated vaccine (CoronaVac) co-administered with an inactivated quadrivalent influenza vaccine: A randomized, open-label, controlled study in healthy adults aged 18 to 59 years in China.

BACKGROUND: Studies are needed for evidence of inactivated COVID-19 vaccine co-administered with influenza vaccine. METHODS: A randomized, open-label, controlled study was conducted in Zhejiang Province, China. Eligible healthy adults aged 18-59 years underwent randomization at a ratio of 1:1:2 to receive inactivated quadrivalent influenza vaccine (IIV4) either concomitantly with the first (C1 subgroup) or the second (C2 subgroup) dose of CoronaVac, or 14 days after the first dose of CoronaVac (S group). The primary purpose of the study was to prove the non-inferiority in seroconversion rate of antibody against SARS-CoV-2. RESULTS: Overall, 480 participants were enrolled, with 120, 120, and 240 randomly assigned to the C1, C2, and S groups, respectively. As lower bound of the two-sided 95% confidence interval (CI) of the difference for the seroconversion rate of antibodies against SARS-CoV-2 was over -10%, the immune response for CoronaVac in the C group (93.1% [89.0, 96.0]) was non-inferior to that in the S group (95.2% [91.5, 97.6]) in the per-protocol set. A lower GMT of antibody against SARS-CoV-2 was observed in the C group as compared to the S group (27.5 vs. 38.1, P = 0.0001). Decrease of immune response to CoronaVac was mainly observed in participants received IIV4 concomitantly with their second dose of CoronaVac (C2 subgroup), with a seroconversion rate of 89.7% (95CI: 82.6%-94.5%) and a GMT of 23.3. The occurrences of vaccine related adverse reactions were no more than 20% and comparable among different groups. Most of the adverse reactions were mild and moderate. CONCLUSION: Co-administration of inactivated COVID-19 vaccine and seasonal influenza vaccine, especially the administration regimen that the seasonal influenza vaccine co-administered with the first dose of the inactivated COVID-19 vaccine, would be feasible.

Knowledge,attitude and practice of influenza vaccine and 23-valent pneumonia vaccine among primary healthcare workers / 预防医学

Objective@#To learn the knowledge,attitude and practice（KAP）of primary healthcare workers on influenza vaccine and 23-valent pneumonia vaccine in Xiuzhou District of Jiaxing,and to provide basis for vaccination of influenza vaccine and 23-valent pneumonia vaccine.@*Methods@#From November 2018 to January 2019,the primary healthcare workers from eight community health service centers in Xiuzhou District were selected by multi-staged random sampling method. A self-designed questionnaire was used to investigate the KAP of influenza vaccine and 23-valent pneumonia vaccine among primary healthcare workers. Logistic regression analysis was employed to select the influencing factors for vaccination and recommendation behaviors of primary healthcare workers. @*Results@# Totally 105 healthcare workers（95.45%）completed the survey. Among them,86（81.90%）and 76（72.38%）workers believed influenza vaccine and 23-valent pneumonia vaccine effective;87（82.85%）and 88（83.81%）workers believed the two vaccines safe;82（78.10%）and 58（55.24%）workers knew the vaccination procedures;58（55.24%）and 34（32.38%）workers knew the key recommended population of vaccines;77（73.33%）workers knew that the vaccine costs could be paid by medical insurance. The vaccination rate of influenza or（and）pneumococcal vaccine among the respondents was 27.62%,and the recommendation rate was 46.67%. The results of multivariate logistic regression analysis showed that healthcare workers who were female（OR=7.250,95%CI：1.388-37.883）,believed the two vaccines effective（OR=4.390,95%CI：1.167-16.515）,believed the two vaccines safe（OR=11.977,95%CI：2.417-59.343）and knew the payment method of vaccine cost（OR=11.945,95%CI：2.924-48.793）were more likely to vaccinate;healthcare workers who majored in public health（OR=2.641,95%CI：1.338-5.214）,believed the two vaccines effective（OR=6.944,95%CI：1.655-29.134）,knew the key recommended population of vaccines（OR=4.380,95%CI：1.125-17.053）,had vaccinated the two vaccines（OR=7.902,95%CI：1.693-36.877）were more likely to recommend. @*Conclusion@#Primary healthcare workers in Xiuzhou District have less awareness of influenza vaccine and 23-valent pneumonia vaccine,then have lower vaccination rate（27.62%）and recommendation rate（46.67%）.

Disease burden of influenza in schools and child care settings in rural areas of Hangzhou, 2016-2018 / 中华预防医学杂志

Objective@#The objective of this study was to analyze the disease burden of influenza in schools and child care settings in rural areas of Hangzhou.@*Methods@#Hospital visit influenza cases aged 3-17 years in hospitals that reported based on influenza surveillance system from 2016 to 2018 in Chun′an county, Hangzhou city were selected as study subjects and a total of 294 confirmed cases of influenza were selected using system sampling method. Questionnaires were designed to investigate the basic information and data on inpatients and outpatients among, health care and life quality, etc.. Direct and indirect economic burden and disability adjusted life year (DALY) were analyzed and compared among different age groups.@*Results@#The mean age of investigated subjects was (8.88±3.92) years. A total of 143 (48.64%) investigated cases were male. In total of 283 (96.26%) cases were outpatients. The total economic burden was 124 743.95 CNY. The mean economic burden was 424.30 CNY per person. The mean direct and indirect economic burden was 361.33 and 62.97 CNY per person respectively. The difference of the mean direct, indirect and total economic burden per person between different age group was statistically significant (P<0.001). The 3-5 years age group showed the highest economic burden with the median value of direct, indirect and total economic burden per person being 276.24, 50.98 and 321.26 CNY, respectively, while the 12-17 years age group showed the lowest values with 175.30, 26.54, 201.79 CNY, respectively. The DALY of 294 influenza cases was 1.18, and the median of burden strength was 3.21 DALY/thousand. The difference of the burden of strength between different age group influenza case was statistically significant (P<0.001), of which the 12-17 years age group showed the highest value with 4.25 DALYs/thousand while the 3-5 years age group showed the lowest value with 2.60 DALY/thousand.@*Conclusion@#The disease burden of influenza was heavy in schools and kindergartens in rural areas of Hangzhou city, with the cases aged from 3 to 5 years showing higher economic burden and cases aged from 12 to 17 years showing greater burden strength.

Application of a self-designed handy body position scaffold in fluoroscopy for lower limb surgery / 中华创伤骨科杂志

Objective To evaluate the application of a self-designed handy body position scaffold in the fluoroscopy for lower limb surgery.Methods We reviewed the intraoperative X-ray films of 161 patients with lower limb fracture who had undergone intraoperative fluoroscopy using our self-made handy body position scaffold during surgery from October 2013 to May 2017.They were 105 males and 56 females,aged from 10 to 91 years (mean,39.7 years).There were 42 femoral fractures of middle or lower shaft,12 fractures of medial or lateral condyle or tibial plateau,96 tibiofibular fractures,7 ankle fractures and 4 foot fractures.The operation time,intraoperative fluoroscopy time,intraoperative bleeding,rate and time of fracture union,and complications were recorded.Results All the 161 patients completed intraoperative fluoroscopy and radiography uneventfully,indicating that the handy body position scaffold effectively maintained the body position of the affected ipsilateral lower limb.The body position scaffold was slightly deviated due to one overweight (121 kg) patient when the knee joint was flexed 90°,but the fluoroscopy and radiography was completed after adjustment of the C-arm roentgenographic machine.The operation time averaged 71.5 minutes (from 28 to 119 minutes),the X-ray exposure time 9.8 seconds (from 6 to 31 seconds),and the intraoperative bleeding 157.2 mL (from 80 to 500 mL).The 161 patients obtained follow-up for 5 to 22 months (average,14.1 months).The rate of primary union was 97.5％ (157/161).The time for fracture union averaged 8.8 weeks (from 4 to 17 weeks).Fracture nonunion occurred in one case,and delayed union in 3 cases.The final follow-ups revealed normal functional recovery of the affected knees and ankles,but no limb shortening,or no rotational,lateral or anteroposterior angulation deformity.Conclusion In the lower limb surgery,the intraoperative fluoroscopy can be completed better with the aid of our self-designed handy body position scaffold that prevents movement of the affected lower limb and lowers the risk of radiation exposure.

A booster dose of an inactivated enterovirus 71 vaccine in chinese young children: a randomized, double-blind, placebo-controlled clinical trial.

BACKGROUND: A significant waning of enterovirus 71 (EV71) antibody titer after priming immunization with an inactivated EV71 vaccine implied the potential need for a booster dose. METHODS: In this randomized, double-blind, placebo-controlled clinical trial, we recruited participants who had received at least 1 dose of priming EV71 vaccine in an early phase 2 clinical trial that was conducted in healthy infants and children aged 6-35 months. All participants were grouped according to the priming EV71 vaccine formulations (160 U, 320 U, and 640 U with adjuvant and 640 U without adjuvant) and then randomly assigned (ratio, 2:1) to receive a booster dose of vaccine or placebo within each formulation group. The primary end point was the geometric mean titer 28 days after the booster dose. RESULTS: A total of 773 participants were enrolled. Significantly greater immunological responses were induced by the booster shot of all 4 formulations of EV71 vaccine, compared with that induced by placebo (P < .0001). The frequencies of adverse reactions were similar between vaccine and placebo groups within each formulation group. CONCLUSIONS: A booster dose of EV71 vaccine 1 year after the priming EV71 immunization shows excellent immunogenicity and good safety profile. Clinical Trials Registration: NCT01734408.