Mutations in the spike RBD of SARS-CoV-2 omicron variant may increase infectivity without dramatically altering the efficacy of current multi-dosage vaccinations

With the continuous evolution of SARS-CoV-2, variants of concern (VOCs) and their mutations are a focus of rapid assessment. Vital mutations in the VOC are found in spike protein, particularly in the receptor binding domain (RBD), which directly interacts with ACE2 on the host cell membrane, a key determinant of the binding affinity and cell entry. With the reporting of the most recent VOC, omicron, we performed amino acid sequence alignment of the omicron spike protein with that of the wild type and other VOCs. Although it shares several conserved mutations with other variants, we found that omicron has a large number of unique mutations. We applied the Hopp-Woods scale to calculate the hydrophilicity scores of the amino acid stretches of the RBD and the entire spike protein, and found 3 new hydrophilic regions in the RBD of omicron, implying exposure to water, with the potential to bind proteins such as ACE2 increasing transmissibility and infectivity. However, careful analysis reveals that most of the exposed domains of spike protein can serve as antigenic epitopes for generating B cell and T cell-mediated immune responses. This suggests that in the collection of polyclonal antibodies to various epitopes generated after multiple doses of vaccination, some can likely still bind to the omicron spike protein and the RBD to prevent severe clinical disease. In summary, while the omicron variant might result in more infectivity, it can still bind to a reasonable repertoire of antibodies generated by multiple doses of current vaccines likely preventing severe disease. Effective vaccines may not universally prevent opportunistic infections but can prevent the sequelae of severe disease, as observed for the delta variant. This might still be the case with the omicron variant, albeit, with increased frequency of infection.

Study of the reference intervals for thyroid-hormones in each trimester of normal pregnancy / 国际检验医学杂志

Objective To survey the thyroid-hormone changes in gravidas,and to establish the reference intervals for thyroid-hormones in each trimester of normal pregnancy in Pingdingshan.Methods 2 645 gravidas who established documents in our hospi-tal were enrolled,The gravidas were divided to different groups by age (≤30 and >30 years old)and 425 cases of early pregnancy women,1 657 cases of middle pregnancy women and 563 cases of late pregnancy women were collected as research group.4 kinds of thyroid functions in the six groups were detected by electrochemical luminescence.Results FT3 and FT4 gradually reduced as the growth of the pregnancy period,but TSH and TPOAb increased.There is statistical difference in all thyroid-hormones between all trimesters of pregnancy and different age groups.Conclusion There is significant difference in thyroid-hormones for different sta-ges of pregnancy and different age groups.Therefore,establishing reference intervals of thyroid-hormones during different stages of pregnancy may be important for clinical practice.