An in-depth investigation of the safety and immunogenicity of an inactivated SARS-CoV-2 vaccine

BACKGROUNDIn-depth investigations of the safety and immunogenicity of inactivated SARS-CoV-2 vaccines are needed. METHODIn a phase I randomized, double-blinded, and placebo-controlled trial involving 192 healthy adults 18-59 years of age, two injections of three different doses (50 EU, 100 EU and 150 EU) of an inactivated SARS-CoV-2 vaccine or the placebo were administered intramuscularly with a 2- or 4-week interval between the injections. The safety and immunogenicity of the vaccine were evaluated within 28 days. FINDINGIn this study, 191 subjects assigned to three doses groups or the placebo group completed the 28-day trial. There were 44 adverse reactions within the 28 days, most commonly mild pain and redness at the injection site or slight fatigue, and no abnormal variations were observed in 48 cytokines in the serum samples of immunized subjects. The serum samples diluted from 1:32 to 1:4096 and incubated with the virus did not show antibody-dependent enhancement effects (ADEs) with regard to human natural killer cells, macrophages or dendritic cells. At day 14, the seroconversion rates had reached 92%, 100% and 96% with geometric mean titers (GMTs) of 18.0, 54.5 and 37.1, and at day 28, the seroconversion rates had reached 80%, 96% and 92% with GMTs of 10.6, 15.4 and 19.6in 0, 14 and 0, 28 procedures, respectively. Seroconversion was associated with the synchronous upregulation of ELISA antibodies against the S protein, N protein and virion and a cytotoxic T lymphocyte (CTL) response. Transcriptome analysis shaped the genetic diversity of immune response induced by the vaccine. INTERPRETATIONIn a population aged 18-59 years, this inactivated SARS-CoV-2 vaccine was safe and immunogenic. Trial registrationNCT04412538 FUNDINGThe National Key R&D Program of China (2020YFC0849700), the Program of Chinese Academy of Medicine Science and the Major Science and Technology Special Projects of Yunnan Province.

A valid protective immune response elicited in rhesus macaques by an inactivated vaccine is capable of defending against SARS-CoV-2 infection

With the relatively serious global epidemic outbreak of SARS-CoV-2 infection, public concerns focus on not only clinical therapeutic measures and public quarantine for this disease but also the development of vaccines. The technical design of our SARS-CoV-2 inactivated vaccine provides a viral antigen that enables the exposure of more than one structural protein based upon the antibody composition of COVID-19 patients convalescent serum. This design led to valid immunity with increasing neutralizing antibody titers and a CTL response detected post-immunization of this vaccine by two injections in rhesus macaques. Further, this elicited immunoprotection in macaques enables not only to restrain completely viral replication in tissues of immunized animals, compared to the adjuvant control and those immunized by an RBD peptide vaccine, but also to significantly alleviate inflammatory lesion in lung tissues in histo-pathologic detection, compared to the adjuvant control with developed interstitial pneumonia. The data obtained from these macaques immunized with the inactivated vaccine or RBD peptide vaccine suggest that immunity with a clinically protective effect against SARS-CoV-2 infection should include not only specific neutralizing antibodies but also specific CTL responses against at least the S and N antigens.

Analysis the characteristics of technology projects in the development of new vaccine products / 中华医学科研管理杂志

Objective To provide references for future government science and technology plan on providing projects for the research and development of new vaccine products.Methods Through analyzing various vaccines that have gained projects from government science and technology plan,this paper summarizes types of science and technology projects,funding proportion and characteristics of science and technology projects at national,provincial and municipal level for vaccine at different research and development stages.Results In general,the supporting categories and levels of projects at different levels are clear.Each research and development stage of new vaccine products has corresponding science and technology planning projects,which are closely linked with each other.Conclusions The government's science and technology funding plays an important role in guiding and promoting the research and development of new vaccine products.

Comparing the immunogenicity and safety of sequential inoculation of sIPV followed by bOPV (Ⅰ+Ⅲ) in different dosage forms / 中华预防医学杂志

Objective@#To compare the safety and immunogenicity of two different sequential schedules of inactivated poliomyelitis vaccine made from Sabin strain (sIPV) followed by typeⅠ+Ⅲ bivalent oral poliovirus vaccine (bOPV) in Drug Candy (DC) form or liquid dosage form).@*Methods@#This randomized, blinded, single center, parallel-group controlled trial was done from September 2015 to June 2016 in Liuzhou, Guangxi province. Healthy infants aged ≥2 months were eligible for enrollment and divided into 1sIPV+2bOPV or 2sIPV+1bOPV sequential schedules. According to the bOPV dosage form each sequential schedules, the subjects again were divided into drug candy(DC) form or liquid dosage form group, being 1sIPV+bOPV (DC)/1sIPV+2bOPV(liquid)/2sIPV+1bOPV(DC)/2sIPV+1bOPV(liquid). According to 0, 28, 56 d immunization schedule, Each group were given 3 doses. We recorded adverse events during the clinical trial (399 participants who receive at least one dose). 28 days post-Dose 3, we receive a total of 350 blood samples (excluding the quitters or subjects against trial plan), using cell culture trace against polio virus neutralization test Ⅰ, Ⅱ, Ⅲ neutralizing antibody (GMT), calculating the antibody positive rate.PolioⅠ,Ⅱand Ⅲ antibody titers were assessed by virus-neutralizing antibody assay and the seroconversion (4-fold increase in titer) from pre-Dose 1 to 28 days post-Dose 3 was calculated (total 350 samples) .@*Results@#During the vaccination, the incidence of AEs in 1sIPV+2bOPV(DC), 1sIPV+2bOPV (liquid), 2sIPV+1bOPV(DC), 2sIPV+1bOPV (liquid) group were 79%, 76%, 80% and 74% (χ2=1.23, P=0.747) , respectively. The severe AEs in groups were 6%, 5%, 6% and 4% (χ2=0.57, P=0.903) , respectively, and none was considered to be vaccination related. 28 days after 3rd vaccination, the seroconversion rates in 1sIPV+2bOPV (DC), 1sIPV+2bOPV (liquid), 2sIPV+1bOPV (DC), 2sIPV+1bOPV (liquid) group, were 99%, 100%, 99% and 99% (χ2=0.94, P=0.815) , respectively, for type Ⅰ poliovirus; and 47%, 57%, 80%, 79% (χ2=31.56, P<0.001) , respectively, for type Ⅱ; and were 100%, 99%, 100%, 99% (χ2=2.02, P=0.568) , respectively, for type Ⅲ. In each group, the GMT of antibody against poliovirus typeⅠ were 4 539.68, 6 243.43, 6 819.53 and 7 916.29 (F=25.87, P<0.001) , respectively; Type Ⅱ were 12.98, 10.54, 63.75 and 84.21 (F=8.68, P=0.034) , respectively; Type Ⅲ were 1 172.55, 1 416.03, 2 648.89 and 3 250.75 (F=14.50, P=0.002) , respectively.@*Conclusion@#On the same sequential schedules, there was no significant difference between the dosage forms, all of them showed good safety and immunogenicity. In the same dosage forms with different sequential schedules, the seroconversion rate was higher in 2 dose sIPV group than the 1 dose sIPV group, especially at the neutralizing antibody GMT level against polio type Ⅱ and Ⅲ after vaccination.

Host Cell Protein C9orf9 Promotes Viral Proliferation via Interaction with HSV-1 UL25 Protein / 中国病毒学·英文版

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.