Neutralizing antibodies and T-cell responses to inactivated SARS-CoV-2 vaccine in COVID-19 convalescents one and a half years after infection.

Vaccines have been considered the most promising solution for ending the coronavirus disease 2019 (COVID-19) pandemic. Information regarding neutralizing antibodies (NAbs) and T-cell immune response in inactivated SARS-CoV-2 vaccine-immunized COVID-19 convalescent patients were either only available for a short time after illness recovered or not available at all (T-cell immunity). We evaluated SARS-CoV-2 NAbs and cellular immune responses to the SARS-CoV-2 inactivated vaccine in convalescent patients who recovered from infection for about one and a half years. We found that compared to before vaccination, SARS-CoV-2 NAbs and specific T-cell responses were significantly boosted by the inactivated vaccine in convalescent patients, which confirmed the pre-existing adaptive immunity in SARS-CoV-2 infected people. We observed that NAbs and IFN-γ-secreting T-cell response elicited by a single vaccine dose in subjects with prior COVID-19 infection were higher than after two doses of vaccine in SARS-CoV-2 naïve subjects. Both humoral and cellular immune responses elicited by one and two doses of inactivated vaccine were comparable in COVID-19-recovered persons. In conclusion, inactivated COVID-19 vaccine induced robust NAbs and T-cell responses to SARS-CoV-2 in COVID-19 convalescent patients and immune responses after one dose were equal to that after receiving two doses, which highlighted that robust humoral and cellular immune response can be reactivated by the inactivated vaccine in SARS-CoV-2 convalescent patients.

Stunting among kindergarten children in China in the context of COVID-19: A cross-sectional study

Background The impact of COVID-19 has most likely increased the prevalence of stunting. The study aimed to determine the prevalence of stunting among kindergarten children in the context of coronavirus disease 2019 (COVID-19) in Longgang District, Shenzhen, China, and its risk factors. Methods A cross-sectional study was conducted to identify children from 11 sub districts of 481 kindergartens in the Longgang District of Shenzhen City from May to July 2021. In the context of COVID-19, an online survey was conducted to gather demographic information, height, birth information, and lifestyle. The prevalence of stunting was calculated, and the risk factors were analyzed using binary logistic regression with three stepwise models. Results A total of 118,404 subjects were included from May to July 2021, with a response and questionnaire effective rates of 85.75% and 95.03%, respectively. The prevalence of stunting and severe stunting were 3.3% and 0.8%, respectively. Model 3 showed that risk factors for stunting were male sex [odds ratio (OR) = 1.07], low birth weight (OR = 2.02), insufficient sleep time (OR = 1.08), less food intake than their peers (OR = 1.66), slower eating than their peers (OR = 1.16), accompanied by grandparents alone or non-lineal relatives (reference: parents accompanying) (OR = 1.23, 1.51), and children induced to eat (OR = 1.17). Protective factors included only-child status (OR = 0.66), reported high activity (OR = 0.37, 0.26, 0.23), parents with high education levels (father: OR = 0.87, 0.69;mother: OR = 0.69, 0.58), high monthly income per capita of the family (OR = 0.88, 0.74, 0.68), and allowing children to make food choices (OR = 0.82). Conclusion The stunting rate of children in kindergartens in Longgang District is 3.3%, close to the level of developed countries but higher than the average level of developed cities in China. The relatively high stunting rate in children under 3 years old in 2021 may be associated with the influence of COVID-19. Appropriate policies should be formulated for individuals and families with children to help children establish good living habits and reduce stunting.

Neutralizing antibodies and cellular immune response after two doses of inactivated SARS-CoV-2 vaccine in China.

BACKGROUND: As of 2022, inactivated SARS-CoV-2 vaccines had been used in more than 91 countries. However, limited real world information was available on the immune responses of the inactivated SARS-CoV-2 vaccine. METHODS: We used SARS-CoV-2 pseudovirues to determine the neutralizing antibodies (NAbs) to wild type and several global variants and utilized enzyme-linked immunosorbent assay to investigate IFN-γ-secreting T-cell responses to SARS-CoV-2 among 240 vaccinated individuals after two doses of inactivated vaccine in China. RESULTS: A majority of the vaccinated (>90%) developed robust NAbs and T-cell responses to SARS-CoV-2 in the first two months after the second dose. After six months, only 37.0% and 44.0% of vaccinees had NAbs and T-cell immunity to SARS-CoV-2, respectively. Immune serum retained most of its neutralizing potency against the Alpha and Iota variants, but lost significant neutralizing potency against the Beta, Kappa, Delta, and Omicron variants. Only 40% of vaccine-sera retained low-level neutralization activities to Omicron, with a 14.7-fold decrease compared to the wild type. CONCLUSION: The inactivated SARS-CoV-2 vaccine stimulated robust NAbs and T-cell immune responses in the first two months after the second dose but the immune effect dropped rapidly, highlighing that a third dose or additional booster immunizations may be required to boost immunity against SARS-CoV-2.

Fetal neurodevelopmental spatio-temporal dynamic transcriptional landscape of maternal insult-induce autism spectrum disorder risk.

Maternal insults during pregnancy induces an increased risk of autism spectrum disorders (ASD) in offspring, but the neuropathological changes in this process remains not to be established. To shed light on this, the transcriptome datasets of maternal blood samples with children later diagnosed with ASD and typical development, and tissue samples of multiple brain regions from ASD patients and human neurodevelopment were conducted to identify the non-chasm differentially expressed genes (DEGs) to generate the spatio-temporal dynamic change. Combined enrichment and interaction network analysis revealed that non-chasm DEGs with similar expression trajectories in the same brain regions, were involved in neural, immune and metabolic GO functions and KEGG pathways, respectively, suggesting that did not performed exactly the same functions. Interestingly, our results found that non-chasm DEGs in frontal cortex and temporal cortex were associated with COVID-19, suggesting that as an environmental risk factor COVID-19 affects an increased risk of ASD.

Neutralizing Antibodies and Cellular Immune Responses Against SARS-CoV-2 Sustained One and a Half Years After Natural Infection.

Background: COVID-19 has caused more than 2.6 billion infections and several million deaths since its outbreak 2 years ago. We know very little about the long-term cellular immune responses and the kinetics of neutralizing antibodies (NAbs) to SARS-CoV-2 because it has emerged only recently in the human population. Methods: We collected blood samples from individuals who were from the first wave of the COVID-19 epidemic in Wuhan between December 30, 2019, and February 24, 2020. We analyzed NAbs to SARS-CoV-2 using pseudoviruses and IgG antibodies to SARS-CoV-2 spike (S) and nucleocapsid (N) protein using enzyme-linked immunosorbent assay in patients' sera and determined SARS-CoV-2-specific T-cell responses of patients with ELISpot assays. Results: We found that 91.9% (57/62) and 88.9% (40/45) of COVID-19 patients had NAbs against SARS-CoV-2 in a year (10-11 months) and one and a half years (17-18 months), respectively, after the onset of illness, indicating that NAbs against SARS-CoV-2 waned slowly and possibly persisted over a long period time. Over 80% of patients had IgG antibodies to SARS-CoV-2 S and N protein one and a half years after illness onset. Most patients also had robust memory T-cell responses against SARS-CoV-2 one and a half years after the illness. Among the patients, 95.6% (43/45) had an IFN-γ-secreting T-cell response and 93.8% (15/16) had an IL-2-secreting T-cell response. The T-cell responses to SARS-CoV-2 were positively correlated with antibodies (including neutralizing antibodies and IgG antibodies to S and N protein) in COVID-19 patients. Eighty percent (4/5) of neutralizing antibody-negative patients also had SARS-CoV-2-specific T-cell response. After long-term infection, protective immunity was independent of disease severity, sex, and age. Conclusions: We concluded that SARS-CoV-2 infection elicited a robust and persistent neutralizing antibody and memory T-cell response in COVID-19 patients, indicating that these sustained immune responses, among most SARS-CoV-2-infected people, may play a crucial role in protection against reinfection.

Translation and Expansion: Enabling Laypeople Access to the COVID-19 Academic Collection.

Academic collections, such as COVID-19 Open Research Dataset (CORD-19), contain a large number of scholarly articles regarding COVID-19 and other related viruses. These articles represent the latest development in combating COVID-19 pandemic in various disciplines. However, it is difficult for laypeople to access these articles due to the term mismatch problem caused by their limited medical knowledge. In this article, we present an effort of helping laypeople to access the CORD-19 collection by translating and expanding laypeople's keywords to their corresponding medical terminology using the National Library of Medicine's Consumer Health Vocabulary. We then developed a retrieval system called Search engine for Laypeople to access the COVID-19 literature (SLAC) using open-source software. Utilizing Centers for Disease Control and Prevention's FAQ questions as the basis for developing common questions that laypeople could be interested in, we performed a set of experiments for testing the SLAC system and the translation and expansion (T&E) process. Our experiment results demonstrate that the T&E process indeed helped to overcome the term mismatch problem and mapped laypeople terms to the medical terms in the academic articles. But we also found that not all laypeople's search topics are meaningful to search on the CORD-19 collection. This indicates the scope and the limitation of enabling laypeople to search on academic article collection for obtaining high-quality information.