ABSTRACT
We examined 169 genomes of SARS-CoV-2 and found that they can be classified into two major genotypes, Type I and Type II. Type I can be further divided into Type IA and IB. Our phylogenetic analysis showed that the Type IA resembles the ancestral SARS-CoV-2 most. Type II was likely evolved from Type I and predominant in the infections. Our results suggest that Type II SARS-CoV-2 was the source of the outbreak in the Wuhan Huanan market and it was likely originated from a super-spreader. The outbreak caused by the Type I virus should have occurred somewhere else, because the patients had no direct link to the market. Furthermore, by analyzing three genomic sites that distinguish Type I and Type II strains, we found that synonymous changes at two of the three sites confer higher protein translational efficiencies in Type II strains than in Type I strains, which might explain why Type II strains are predominant, implying that Type II is more contagious (transmissible) than Type I. These findings could be valuable for the current epidemic prevention and control.
ABSTRACT
Objective:To assess the antibody persistence 3-5 years following vaccination of measles and rubella combined live-attenuated vaccine (MR) at 8 months of age and measles, mumps and rubella combined attenuated live vaccine (MMR) at 18 months of age.Methods:In 2016, 18-month-old children who were vaccinated with one dose of MR vaccine at the age of 8 months were recruited in Hebei Province as group 1; 4-, 5- and 6-year-old children who were vaccinated with one dose of MR vaccine at the age of 8 months and one dose of MMR vaccine at 18 months of age were recruited in Shanxi, Inner Mongolia and Beijing as group 2, group 3 and group 4, respectively. Serum samples were collected to detect IgG antibodies against measles, mumps and rubella by ELISA. Geometric mean concentrations (GMCs) of measles, mumps, and rubella antibodies were compared among groups by analysis of variance or non-parametric test. Seropositive rates were compared among groups by Chi-square test or Fisher′s exact test. Results:A total of 650 children were included in this study. Seropositive rates of measles, mumps and rubella antibodies 30 d after vaccination of 150 18-month-old children with one dose of MMR vaccine were 100%, 91.33% and 100%, respectively, and the GMCs were 1 846.87 mIU/ml, 299.91 IU/ml and 111.33 IU/ml, respectively. Seropositive rates of measles, mumps and rubella antibodies 3-5 years after vaccination one dose of MR vaccine at 8 months of age and one dose of MMR vaccine at 18 months of age were above 94%, 79% and 71%, respectively, and the GMCs were above 830 mIU/ml, 240 IU/ml and 31 IU/ml. No significant difference in the seropositive rates of the three antibodies was observed among groups 2, 3 and 4 ( P>0.05). There was no significant difference in the GMCs of measles or mumps antibodies among the three groups ( P>0.05), but the differences in the GMCs of rubella antibodies were statistically significant ( P=0.034). Conclusions:Measles, mumps and rubella antibodies persisted for 3-5 years without significant decrease after vaccination one dose of MR vaccine at 8 months of age and one dose of MMR vaccine at 18 months of age.
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Objective To investigate in vitro combined effect of ceftriaxone and azithromycin against clinical isolates of Neisseria gonorrhoeae(NG). Methods A total of 25 NG clinical isolates were collected from the STD clinic of Dalian Dermatosis Hospital in 2012. Epsilometer test(Etest)method was used to determine the minimum inhibitory concentrations(MICs)of ceftriaxone and azithromycin against NG isolates. Fractional inhibitory concentration index (FICI) was calculated to evaluate the in vitro combined effect of ceftriaxone and azithromycin against NG isolates. Results The mean MICs of ceftriaxone and azithromycin were 0.032 mg/L (range, 0.008- 0.064 mg/L) and 0.834 mg/L (range, 0.064-4.000 mg/L), respectively. The FICI ranged from 0.724 to 2.696, and ceftriaxone and azithromycin showed an additive effect against the above NG isolates. Conclusion Ceftriaxone and azithromycin show an additive effect against NG in vitro, but further studies with large sample size are needed to confirm their effects.
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Objective To analyze the characteristics of adverse events following immunization ( AEFI) with varicella attenuated live vaccine ( VarV) in Hebei province during 2012—2014, to evaluate the safety of VarV and to provide supportive evidences for planning chicken pox prevention and control strate-gies in Hebei province.Methods The AEFI data associated with VarV in Hebei province during 2012 to 2014 were collected from the national AEFI information management system and were analyzed by using the method of descriptive epidemiology.Results A total of 239 cases reported during 2012 to 2014 were col-lected from the national AEFI information management system, with a male to female ratio of 1.44 ∶1.The estimated incidence rate was 25.51 per 100 000 doses.One case was serious AEFI with an incidence rate of 0.11 per 100 000 doses.Most of the AEFI cases were children under 3 years old and identified in scattered inhibiting children and kindergarten kids.The main symptoms of common vaccine reactions were fever, local swelling and induration .The rare vaccine reactions were presented as anaphylactic rashes .Conclusion The reported incidence rate of VarV associated AEFI in Hebei province was less than expected.However, the estimated incidence rate of common vaccine reactions in Hebei province was higher than that showed on the Analysis on Surveillance Data of Post-marketing Immunization Safety for Varicella Attenuated Live Vac-cine in China, 2010—2012.Attentions to the AEFI after immunization with VarV should also be paid in fu-ture.
