Early assessment of the safety and immunogenicity of a third dose (booster) of COVID-19 immunization in Chinese adults.

Inducing durable and effective immunity against severe acute respiratory syndrome Coronavirus 2 (SARS-CoV-2) via vaccination is essential to combat the current pandemic of coronavirus disease 2019 (COVID-19). It has been noticed that the strength of anti-COVID-19 vaccination-induced immunity fades over time, which calls for an additional vaccination regime, as known as booster immunization, to restore immunity among previously vaccinated populations. Here we report a pilot open-label trial of a third dose of BBIBP-CorV, an inactivated SARS-CoV-2 vaccine (Vero cell), on 136 participants aged between 18 to 63 years. Safety and immunogenicity in terms of neutralizing antibody titers and cytokine/chemokine responses were analyzed as the main endpoint until day 28. While systemic reactogenicity was either absent or mild, SARS-CoV-2-specific neutralizing antibody titers rapidly arose in all participants within 4 weeks, surpassing the peak antibody titers elicited by the initial two-dose immunization regime. Broad increases of cellular immunity-associated cytokines and chemokines were also detected in the majority of participants after the third vaccination. Furthermore, in an exploratory study, a newly developed recombinant protein vaccine, NVSI-06-08 (CHO Cells), was found to be safe and even more effective than BBIBP-CorV in eliciting humoral immune responses in BBIBP-CorV-primed individuals. Together, these results indicate that a third immunization schedule with either homologous or heterologous vaccine showed favorable safety profiles and restored potent SARS-CoV-2-specific immunity, providing support for further trials of booster vaccination in larger populations.

Occurrence and risk assessment of heavy metals in an urban river supplied by reclaimed wastewater.

Heavy metals in reclaimed water are a global problem that leads to ecological risks for the replenishment water body. This study investigated concentrations and ecological risks posed by heavy metals in SH River, Beijing, which is supplied by reclaimed water. Results showed that Cr was not detected in the sample, Cd and Pb exceeded threshold values according to regulations by 1.19% and 25.00%, respectively. The characterization of temporal and spatial of heavy metals was studied. The potential ecological risks posed by heavy metals in SH River were found to be low and safe. The risk decreased in the order Pb > Cu > Zn > Ni > Cd > As by comprehensive index assessment; this changed to Pb > Cd > As > Ni > Cu > Zn according to potential ecological risk assessment. Pb posed the greatest ecological risks and was identified as most contaminated metal. According to discussion of sampling sites and water quality, it was proposed that reclaimed water and exogenous discharges were the main sources of the heavy metals identified. This should be considered when developing catchment management strategies for heavy metals elimination and protection of the aquatic environment. If a higher level of ecological risk management is required, Pb, Cd, and Cu should be considered first and should be removed in situ through ecological remediation methods. PRACTITIONER POINTS: Reclaimed water and exogenous discharges were the main sources of the heavy metals identified. The potential ecological risks posed by heavy metals in SH River were found to be low and safe. The risk decreased in the order Pb > Cu > Zn > Ni > Cd > As by comprehensive index assessment. Potential ecological risk assessment showed Pb > Cd > As > Ni > Cu > Zn. Pb posed the greatest ecological risks and was identified as most contaminated metal.