Immunogenicity and lot-to-lot consistency of booster shot with Sabin inactivated poliomyelitis vaccine in Chinese children aged 18-24 Months: A phase â £ clinical trial.

BACKGROUND: There has been no data on the immunogenicity and safety of the 4th booster dose of the sIPV immunization in 18-24 months old children in post-marketing studies of large cohort providing with robust results. METHOD: In a phase Ⅳ randomized, double-blinded clinical trial, 1200 participants aged 2 months were immunized with three consecutive doses of sIPV at 2, 3, and 4 months old to complete primary immunization. Out of the 1200 participants, 1129 received the 4th dose of sIPV as booster immunization. Immunogenicity was evaluated in 1100 participants. RESULTS: Seropositive rates of the anti-poliovirus type 1, 2, and 3 neutralizing antibodies were 99.9 %, 98.0 %, 98.2 %, respectively, with GMTs of 557.0, 146.1, 362.0 one year after primary vaccination. After booster vaccination between 18 and 24 months old, the seropositive rates for 3 types all reached 100.0 %, with GMTs of 8343.6, 5039.6, 5492.0, respectively. Particularly for the anti-poliovirus type 2 antibody, the GMT was 230.4 after primary immunization, maintained to 146.1 one year after primary immunization, and increased to as high as 5039.6 after booster vaccination. The GMT ratios between each batch groups after booster immunization were between 0.67 and 1.50, meeting the immunological equivalence criteria. The incidence rate of adverse reaction was 23.0 %, which was comparable to those in the phase Ⅲ trial but had a lower incidence. Furthermore, no SUSAR was reported in this study. INTERPRETATION: In conclusion, as the anti-poliovirus antibodies gradually waned one year post sIPV primary vaccination, especially the type 2 antibody waned to a very low level, suggesting the importance of the booster immunization for children at the age of 18-24 months old. The booster shot can greatly enhance the antibody level and protect children from the potential risk of infection with WPV and VDPV by supplementing the anti-poliovirus type 2 immunity gap in the current real world. Clinic Trial Registration. NCT04224519.

Quantitative Analysis of the Instant and Persistent Inhibition Effects of Maternal Poliovirus Antibodies on the Immune Response in a Phase IV Trial of a Sabin Strain-Based Inactivated Poliovirus Vaccine.

BACKGROUND: An inactivated poliomyelitis vaccine made from Sabin strains (sIPVs) has widely been used in China since 2015. However, the quantitative data on the instant and persistent inhibition effects of maternal poliovirus antibodies on the immune response to sIPV priming and booster vaccination have not been available yet. OBJECTIVE: In this study, we aim to explore and quantify the instant and persistent inhibition effect of maternal poliovirus antibodies on the immune response elicited by sIPV primary and booster vaccination. METHODS: The immunogenicity data consisting of the days 0 and 30 after the prime and booster vaccination of the sIPV in a phase IV trial were pooled for a quantitative analysis of the inhibition effect of maternal poliovirus antibody. The geometric mean ratio (GMR) was calculated using linear regression models, representing that every 2-fold higher maternal poliovirus antibody titer may result in a (1-GMR) lower postimmunization antibody titer. RESULTS: The GMRs for poliovirus types 1, 2, and 3 were 0.79 (0.77-0.82), 0.85 (0.81-0.89), and 0.87 (0.83-0.91) at 30 days after the priming series, 0.86 (0.83-0.89), 0.81 (0.76-0.85), and 0.86 (0.80-0.93) at one year after the priming series, and 0.96 (0.94-0.99), 0.89 (0.86-0.93), and 0.98 (0.93-1.03) at 30 days after the booster dose. The inhibition effect continued to exist until the booster dose 1 year later, and such a persistent inhibition effect was almost attenuated for poliovirus types 1 and 3, and partly reduced for type 2 at 30 days after the booster dose. CONCLUSION: A wider interval between the four sIPV doses might be a consideration for reducing the effect of maternal antibodies and subsequently eliciting and maintaining higher antibody levels to protect against poliovirus transmission and infection at the final stage of polio eradication in the global world. This study's clinical trial registry number is NCT04224519.

Immune persistence after different polio sequential immunization schedules in Chinese infants.

Trivalent oral poliovirus vaccine (tOPV) has been withdrawn and instead an inactivated poliovirus vaccine (IPV) and bivalent type 1 and type 3 OPV (bOPV) sequential immunization schedule has been implemented since 2016, but no immune persistence data are available for this polio vaccination strategy. This study aimed to assess immune persistence following different polio sequential immunization schedules. Venous blood was collected at 24, 36, and 48 months of age from participants who had completed sequential schedules of combined IPV and OPV in phase III clinical trials. The serum neutralizing antibody titers against poliovirus were determined, and the poliovirus-specific antibody-positive rates were evaluated. A total of 1104 participants were enrolled in this study. The positive rates of poliovirus type 1- and type 3-specific antibodies among the sequential immunization groups showed no significant difference at 24, 36, or 48 months of age. The positive rates of poliovirus type 2-specific antibody in the IPV-IPV-tOPV group at all time points were nearly 100%, which was significantly higher than the corresponding rates in other immunization groups (IPV-bOPV-bOPV and IPV-IPV-bOPV). Immunization schedules involving one or two doses of IPV followed by bOPV failed to maintain a high positive rate for poliovirus type 2-specific antibody.

Immunogenicity and safety of the inactivated enterovirus 71 vaccine administered concomitantly with the measles-rubella vaccine in infants aged 8 months in China: A noninferiority randomized controlled trial.

BACKGROUND: To evaluate the immunogenicity and safety of simultaneous administration of the enterovirus 71 (EV71) vaccine with the measles and rubella (MR) combined vaccine. METHODS: In this phase 4, randomized, open-label and noninferiority study, a total of 680 infants aged 8 months were enrolled and assigned to the simultaneous administration group (infants received the first dose of EV71 vaccine and MR vaccine on Day 0, and the second dose of EV71 vaccine on Day 28), or the separate administration groups (EV71 group: infants received two doses of EV71 vaccine on Day 0 and Day 28, respectively; MR group: infants received MR vaccine on Day 0). Blood sample was obtained on Day 0 and Day 56 to measure antibody responses to each of the antigens in terms of antibody titer or concentration, respectively. Local and systemic adverse reactions (ARs) and other adverse events (AEs) following each dose were monitored and compared among groups. RESULTS: After vaccination, simultaneous administration group showed similar seroconversion rates of antibody against EV71(97.9%), measles (97.4%), and rubella (94.3%) compared to EV71 group (99.6% for anti-EV71) or MR group (98.4% for anti-measles and 98.9% for anti-rubella, respectively). Noninferiority was demonstrated for all antibodies as the lower limits of two-sided 97.5% confidence intervals (CIs) of the difference in seroconversion rates between simultaneous administration group and separate administration groups were above the predefined margin of -10%. Additionally, the adverse reaction rates were comparable among groups (54.4% in the simultaneous group versus 43.9% in the MR group versus 52.6% in the EV71 group). CONCLUSION: Antibody responses induced by simultaneous administration of EV71 vaccine with MR vaccine were robust and noninferior to those by single administration alone. Like the previous findings by single administration alone, simultaneous administration demonstrated comparable reactogenicity and safety profiles.

Immunological evaluation of an inactivated SARS-CoV-2 vaccine in rhesus macaques.

Because of the relatively limited understanding of coronavirus disease 2019 (COVID-19) pathogenesis, immunological analysis for vaccine development is needed. Mice and macaques were immunized with an inactivated severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccine prepared by two inactivators. Various immunological indexes were tested, and viral challenges were performed on day 7 or 150 after booster immunization in monkeys. This inactivated SARS-CoV-2 vaccine was produced by sequential inactivation with formaldehyde followed by propiolactone. The various antibody responses and specific T cell responses to different viral antigens elicited in immunized animals were maintained for longer than 150 days. This comprehensive immune response could effectively protect vaccinated macaques by inhibiting viral replication in macaques and substantially alleviating immunopathological damage, and no clinical manifestation of immunopathogenicity was observed in immunized individuals during viral challenge. This candidate inactivated vaccine was identified as being effective against SARS-CoV-2 challenge in rhesus macaques.

The safety and immunogenicity of an inactivated SARS-CoV-2 vaccine in Chinese adults aged 18-59 years: A phase I randomized, double-blinded, controlled trial.

BACKGROUND: This study examined the safety and immunogenicity of an inactivated SARS-CoV-2 vaccine. METHOD: In a phase I randomized, double-blinded, placebo-controlled trial involving 192 healthy adults 18-59 years old, two injections of three doses (50 EU, 100 EU, 150 EU) of an inactivated SARS-CoV-2 vaccine or placebo were administered intramuscularly at a 2- or 4-week interval. The safety and immunogenicity of the vaccine were evaluated. RESULTS: Vaccination was completed in 191 subjects. Forty-four adverse reactions occurred within 28 days, most commonly mild pain and redness at the injection site or slight fatigue. At days 14 and 28, the seroconversion rates were 87.5% and 79.2% (50 EU), 100% and 95.8% (100 EU), and 95.8% and 87.5% (150 EU), respectively, with geometric mean titers (GMTs) of 18.1 and 10.6, 54.5 and 15.4, and 37.1 and 18.5, respectively, for the schedules with 2-week and 4-week intervals. Seroconversion was associated with synchronous upregulation of antibodies against the S protein, N protein and virion and a cytotoxic T lymphocyte (CTL) response. No cytokines and immune cells related to immunopathology were observed. Transcriptome analysis revealed the genetic diversity of immune responses induced by the vaccine. INTERPRETATION: In a population aged 18-59 years in this trial, this inactivated SARS-CoV-2 vaccine was safe and immunogenic. TRIAL REGISTRATION: CTR20200943 and NCT04412538.

Post hoc analysis of two clinical trials to compare the immunogenicity and safety of different polio immunization schedules in Chinese infants.

BACKGROUND: A comparative analysis of the immunogenicity and safety of different poliovirus immunization schedules in Chinese infants is imperative to guide the administration of efficient strategies for the eradication of poliomyelitis. METHODS: A post hoc analysis was conducted with the data from two poliovirus vaccine clinical trials involving a combined total of 2,400 infants aged 60-90 days. Trivalent oral poliovirus vaccine (tOPV), bivalent oral poliovirus vaccine (bOPV), Sabin strain-based inactivated poliovirus vaccine (sIPV), and conventional inactivated poliovirus vaccine (cIPV) were used in different schedules, the immunogenicity and safety of which were compared 28 days after the last of three doses. RESULTS: In a per-protocol set analysis, the tOPV-tOPV-tOPV schedule induced seroconversion in 99.1%, 98.2%, and 96.0% of the inoculated infants for poliovirus type I, II, and III, respectively. The seroconversions for poliovirus types I and III were each almost 100% after immunization with the cIPV-bOPV-bOPV, sIPV-sIPV-bOPV, cIPV-cIPV-bOPV, sIPV-sIPV-tOPV, cIPV-cIPV-tOPV, or sIPV-bOPV-bOPV schedule. However, the schedules that used one IPV dose followed by two (poliovirus type I and III) bOPV doses failed to induce high-level immunity against type II poliovirus. IPV-related schedules were associated with a slightly higher incidence of adverse events (AEs). CONCLUSIONS: If the capacity of IPV can be increased, two or more doses of IPV should be administered before vaccination with bOPV in a sequential schedule to improve immunity against type II poliovirus.

Immunogenicity and safety of the inactivated poliomyelitis vaccine made from Sabin strains in a phase IV clinical trial for the vaccination of a large population.

As a recently launched novel vaccine used as one of the vaccines for the final eradication of polios worldwide, complete data on the consistency and immunogenicity characteristics of the inactivated poliomyelitis vaccine made from the Sabin strain (sIPV) and its safety in large-scale populations are required to support the future use of this vaccine worldwide. A phase IV clinical trial was conducted to perform an immunogenicity evaluation of lot-to-lot consistency of three commercial batches of sIPV in 1200 infants and to investigate the vaccine's safety on a large-scale in 20,019 infants for active monitoring and 29,683 infants for passive monitoring through the Adverse Event Following Immunization (AEFI) reporting system in China. In the immunogenicity evaluation, the average seroconversion rates for type I, type II and type III of the three groups were 99.83%, 98.93% and 99.44%, respectively. No differences in the seroconversion rate and the GMT ratios were noted in the pair-to-pair comparisons. In the large-scale safety evaluation, most adverse reactions occurred 0-30 days after the first doses, and the common local and systemic reactions were similar to those in the phase III clinical trial, with low incidence in both activated and passive monitoring. In conclusion, sIPV exhibits good lot-to-lot consistency and safety in large-scale populations; thus, it is qualified to serve as one of the vaccines for use in eradicating all wild and vaccine-derived polioviruses worldwide in the near future. Clinic Trial Registration. NCT04224519 and NCT04220515.

Randomized, Double-Blinded, Placebo-Controlled Phase 2 Trial of an Inactivated Severe Acute Respiratory Syndrome Coronavirus 2 Vaccine in Healthy Adults.

BACKGROUND: We evaluated an inactivated severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccine for immunogenicity and safety in adults aged 18-59 years. METHODS: In this randomized, double-blinded, controlled trial, healthy adults received a medium dose (MD) or a high dose (HD) of the vaccine at an interval of either 14 days or 28 days. Neutralizing antibody (NAb) and anti-S and anti-N antibodies were detected at different times, and adverse reactions were monitored for 28 days after full immunization. RESULTS: A total of 742 adults were enrolled in the immunogenicity and safety analysis. Among subjects in the 0, 14 procedure, the seroconversion rates of NAb in MD and HD groups were 89% and 96% with geometric mean titers (GMTs) of 23 and 30, respectively, at day 14 and 92% and 96% with GMTs of 19 and 21, respectively, at day 28 after immunization. Anti-S antibodies had GMTs of 1883 and 2370 in the MD group and 2295 and 2432 in the HD group. Anti-N antibodies had GMTs of 387 and 434 in the MD group and 342 and 380 in the HD group. Among subjects in the 0, 28 procedure, seroconversion rates for NAb at both doses were both 95% with GMTs of 19 at day 28 after immunization. Anti-S antibodies had GMTs of 937 and 929 for the MD and HD groups, and anti-N antibodies had GMTs of 570 and 494 for the MD and HD groups, respectively. No serious adverse events were observed during the study period. CONCLUSIONS: Adults vaccinated with inactivated SARS-CoV-2 vaccine had NAb as well as anti-S/N antibody and had a low rate of adverse reactions. CLINICAL TRIALS REGISTRATION: NCT04412538.

Effectiveness and Safety of an Inactivated Enterovirus 71 Vaccine in Children Aged 6-71 Months in a Phase IV Study.

BACKGROUND: Evaluation of a licensed inactivated enterovirus type 71 (EV71) vaccine is needed in a phase IV study with a large population to identify its effectiveness and safety for further application. METHODS: An open-label, controlled trial involving a large population of 155 995 children aged 6-71 months was performed; 40 724 were enrolled in the vaccine group and received 2 doses of inactivated EV71 vaccine at an interval of 1 month, and the remaining children were used as the control group. The EV71-infected cases with hand, foot, and mouth disease were monitored in the vaccine and control groups during a follow-up period of 14 months since the 28th day postinoculation through the local database of the Notifiable Infectious Diseases Network. The effectiveness of the vaccine was estimated by comparing the incidence density in the vaccine group versus that in the control group based upon EV71-infected patients identified via laboratory testing. In parallel, the active and passive surveillance for safety of the vaccine was conducted by home or telephone visits and by using the Adverse Event Following Immunization (AEFI) system, respectively. RESULTS: An overall level of 89.7% (95% confidence interval, 24.0-98.6%) vaccine effectiveness against EV71 infection and a 4.58% rate of reported adverse events were observed. Passive surveillance demonstrated a 0.31% rate of reported common minor reactions. CONCLUSIONS: The clinical protection and safety of the EV71 vaccine were demonstrated in the immunization of a large population. CLINICAL TRIALS REGISTRATION: NCT03001986.

[Epidemiological characteristics of mumps in mainland China from 2004 to 2018 and key population for prevention and control].

OBJECTIVE: To investigate the epidemiological characteristics of mumps in mainland China from 2004 to 2018, and to provide data for the key population for prevention and control of mumps. METHODS: The epidemiological characteristics of mumps were analyzed with reference to the data of the cases of mumps reported in the National Scientific Data Sharing Platform for Population and Health and Disease Prevention and Control Bureau of National Health Commission of the People's Republic of China. Descriptive epidemiology was used to analyze the epidemiological characteristics of mumps. RESULTS: A total of 4 272 368 cases of mumps were reported in China during 2004-2018, with an average annual reported incidence rate of 21.44/100 000. A single dose of mumps-containing vaccine was added to the national Expanded Program of Immunization in 2008, but the annual incidence rate ranged from 12.84/100 000 to 35.59/100 000. The second dose of measles, mumps and rubella combined attenuated live vaccine was included in the routine immunization in Beijing, Tianjin and Shanghai, and then the average incidence rate of mumps reported in these three regions dropped to about 10/100 000. From 2004 to 2016, the population aged 3-14 years accounted for 81.16% of all patients with mumps. The children aged 6 years had the highest incidence rate of mumps during 2004-2013. CONCLUSIONS: A single dose of mumps-containing vaccine has no obvious effect on the incidence rate of mumps. Children aged 6 years have the highest incidence rate of mumps. A booster dose of mumps-containing vaccine should be given to preschool children.

Host cell protein C9orf69 promotes viral proliferation via interaction with HSV-1 UL25 protein.

In light of the scarcity of reports on the interaction between HSV-1 nucleocapsid protein UL25 and its host cell proteins, the purpose of this study is to use yeast two-hybrid screening to search for cellular proteins that can interact with the UL25 protein. C9orf69, a protein of unknown function was identified. The interaction between the two proteins under physiological conditions was also confirmed by biological experiments including co-localization by fluorescence and immunoprecipitation. A preliminary study of the function of C9orf69 showed that it promotes viral proliferation. Further studies showed that C9orf69 did not influence viral multiplication efficiency by transcriptional regulation of viral genes, but indirectly promoted proliferation via interaction with UL25.