Broad neutralization against SARS-CoV-2 variants induced by a modified B.1.351 protein-based COVID-19 vaccine candidate

Beginning in late 2020, the emergence and spread of multiple variant SARS-CoV-2 strains harboring mutations which may enable immune escape necessitates the rapid evaluation of second generation COVID-19 vaccines, with the goal of inducing optimized immune responses that are broadly protective. Here we demonstrate in a mouse immunogenicity study that two doses of a modified B.1.351 spike (S)-Trimer vaccine (B.1.351 S-Trimer) candidate can induce strong humoral immune responses that can broadly neutralize both the original SARS-CoV-2 strain (Wuhan-Hu-1) and Variants of Concern (VOCs), including the UK variant (B.1.1.7), South African variant (B.1.351) and Brazil variant (P.1). Furthermore, while immunization with two doses (prime-boost) of Prototype S-Trimer vaccine (based on the original SARS-CoV-2 strain) induced lower levels of cross-reactive neutralization against the B.1.351 variant, a third dose (booster) administered with either Prototype S-Trimer or B.1.351 S-Trimer was able to increase neutralizing antibody titers against B.1.351 to levels comparable to neutralizing antibody titers against the original strain elicited by two doses of Prototype S-Trimer.

S-Trimer, a COVID-19 subunit vaccine candidate, induces protective immunity in nonhuman primates

SARS-CoV-2 is the underlying cause for the COVID-19 pandemic. Like most enveloped RNA viruses, SARS-CoV-2 uses a homotrimeric surface antigen to gain entry into host cells. Here we describe S-Trimer, a native-like trimeric subunit vaccine candidate for COVID-19 based on Trimer-Tag technology. Immunization of S-Trimer with either AS03 (oil-in-water emulsion) or CpG 1018 (TLR9 agonist) plus alum adjuvants induced high-levels of neutralizing antibodies and Th1-biased cellular immune responses in animal models. Moreover, rhesus macaques immunized with adjuvanted S-Trimer were protected from SARS-CoV-2 challenge compared to vehicle controls, based on clinical observations and reduction of viral loads in lungs. Trimer-Tag may be an important new platform technology for scalable production and rapid development of safe and effective subunit vaccines against current and future emerging RNA viruses.

Epidemic and clinical characteristics of 1 976 children with hand-feet-mouth disease in Chengdu, 2018 to 2019 / 中华传染病杂志

Objective:To analyze the epidemiological and clinical characteristics of hand-feet-mouth disease (HFMD).Methods:The clinical and pathogenic data of 1 976 cases with HFMD hospitalized in Public Health Clinical Center of Chengdu from August 2018 to September 2019 were retrospective analyzed.Results:Among the 1 976 cases of HFMD, 1 094 cases (55.36%) were one to two years old, and 803 cases (40.64%) lived in the main urban area. The majority were scattered patients (1 344 cases, 68.02%). There were 1 348(72.7%) of 1 854 cases mainly infected by Coxsackie virus 6 (CV-A6). The main distribution of rashes in children infected by CV-A6 were palm/soles, trunks, limbs, oral ulcer and perioral areal, lips and hip. The types of rash were maculopapule, vesicle, and bulla. Fever (1 543 cases, 78.09%) was the main concomitant symptom. Acute tonsillitis (811 cases, 41.04%), myocardial injury (767 cases, 38.82%), and herpetic angina (658 cases, 33.30%) were the most common complications. The incidence of onychomadesis were nine (7.03%) among the 128 patients during follow-up.Conclusions:CV-A6 is the main pathogen of the HFMD prevalence. Children less than two years old are susceptible and the main symptoms of HFMD are rash and fever.

Effect of anti-syphilis treatment on perinatal outcomes and neonatal prognosis in pregnant women complicated with syphilis / 中华临床感染病杂志

Objective To investigate the effect of anti-syphilis treatment on the perinatal outcomes and neonatal prognosis in pregnant women complicated with syphilis.Methods One hundred and ninety eight pregnant women complicated with syphilis were collected from Chengdu Hospital of Infectious Diseases during January 2010 and January 2012,including 98 cases received standard treatment,59 cases received nonstandard treatment and 41 cases did not receive treatment.Pearson x2 and partition of chi-square were used for the comparison of pregnant outcomes,neonatal prognosis and negative rates of rapid plasma circle card test (RPR) among 3 groups.Results The incidence of adverse pregnancy outcomes,including miscarriage,prematurity,still birth and congenital malformation were 4.08％,27.12％ and 63.41％ in three groups,respectively.The incidence of congenital syphilis,low birth weight,asphyxia in infants and neonatal death raised in from standard-treatment group,nonstandard-treatment group to untreated group.Congenital syphilis rates were 2.04％,18.75％ and 35.29％ in three groups,respectively.RPR titers in newborns from mothers with high RPR titer (≥ 1 ∶ 8) in standard-treatment group were significantly lower than those in nonstandard-treatment group and untreated group (x2 =37.122,P ＜ 0.01).RPR negative rates were 100.00％,59.26％ and 25.00％ in three groups,respectively (x2 =18.839,P ＜ 0.01).Conclusion Standard anti-syphilis treatment can improve pregnant outcome,neonatal prognosis and reduce the incidence of congenital syphilis.

The prediction of maternal HBV transmission by breast milk of postpartum women with chronic HBV infection / 中华临床感染病杂志

Objective To investigate the prediction of maternal HBV transmission by breast milk of postpartum women with chronic HBV infection.Methods HBV DNA levels in serum and breast milk weredetected by fluorescent quantitative polymerase chain reaction in 64 postpartum women with chronic HBV infection.HBV DNA≥1.0×103copies/ml was defined as positive,and correlation analysis was conducted.Results HBV DNA positive rate was 78.1%and 62.5%in serum and breast milk respectively,with a HBV DNA range of 1.05×103～3.87 ×104copies/ml in breast milk.When HBV DNA in serum was 1.0×105～1.0×107copies/ml,the HBV DNA positive rate in breast milk reached to 94.9%;however,when HBV DNA in serum was 1.0×103～1.0×104copies/ml,the positive rate in breast milk was only 18.2%.Conclusion The HBV DNA positive rate of breast milk in postpartum women with chronic HBV infection is correlated with the HBV DNA levels in serum;and breast-feeding should be avoided for postpartum women with HBV DNA≥1.0×105copies/ml in the serum.So serum HBV DNA detection is necessary in antenatal care for women with chronic HBV infection.