Protection of Omicron Sub-Lineage Infection Against Reinfection with Another Omicron Sub-Lineage: Systematic Review, Meta-Analysis, and Meta-Regression - Worldwide, 2022-2023.

What is already known about this topic?: Both the decline in immunity over time and the evolution of the virus play a role in the level of protection offered by a prior infection. What is added by this report?: Point estimates indicated variations in protection levels based on the initial infecting variant and the reinfecting variant. There was a consistent correlation between real-world protection, antigenic distance, and humoral immunity levels. Specifically, shorter antigenic distances and higher humoral immunity levels corresponded to enhanced real-world protection. What are the implications for public health practice?: Our findings suggest that virological and immunological studies could help identify and assess the epidemic risk posed by new variants before they become dominant. Prompt incorporation of the latest variants into the antigen components of the coronavirus disease 2019 (COVID-19) vaccines can significantly contribute to effective epidemic prevention and control measures.

The COVID-19 Vaccines Evaluation Program: Implementation, Management, and Experiences, 2021-2023.

In 2021, China's domestically produced coronavirus disease 2019 (COVID-19) vaccines received approval from regulatory bodies and were administered worldwide. Due to a low number of infections within China during that period, it became imperative to evaluate the vaccines' real-world effectiveness through international studies. To facilitate this, China CDC launched the COVID-19 Vaccines Evaluation Program (COVEP). This program formed research collaboration agreements with health institutes across five World Health Organization regions, addressing key questions about vaccine performance through ten cooperative agreements. The findings from COVEP projects reinforced confidence, both domestically and globally, in the effectiveness of the vaccines produced in China. Moreover, the outcomes observed internationally were frequently mirrored by later studies conducted within China. COVEP thus pioneered a novel approach for fostering cross-national research collaborations, addressing significant public health issues and exemplifying a framework for international cooperation. This approach is in line with the strategic objectives and other development efforts of China CDC's national disease control and prevention initiatives.

Core-shell structured alginate-based hydrogel beads modified by starch and protocatechuic acid: Preparation, characterization, phenolic slow release and stable antioxidant potential.

A novel core-shell structured alginate-based hydrogel bead modified by co-gelatinizing with starch and protocatechuic acid (PA), was designed to modulate physical properties of beads, release behavior and antioxidant stability of encapsulated bioactives. Core was fabricated by ionotropic gelation, and its formulation (ratio of sodium alginate/starch) was determined by particle size/starch distribution, texture and bioactive encapsulation capacity of core. Then, coating core with shell-forming solution co-gelatinized with different doses of PA, and subsequently cross-linked with Ca2+ to obtain core-shell structured beads. Surface microstructure, mechanical characteristics, and swelling ratio of beads were affected by concentrations of PA. Besides, core-shell structure containing PA could enhance delivery and sustained release of encapsulated phenolic bioactives during in vitro digestion, and improve their antioxidant potential stability. Furthermore, interaction between PA and polysaccharide components was elucidated by FTIR and TGA. The present information was beneficial for the advancement of functional food materials and bioactive delivery systems.

Safety, Immunogenicity, and Effectiveness of Chinese-Made COVID-19 Vaccines in the Real World: An Interim Report of a Living Systematic Review.

Background: Several COVID-19 vaccines were developed and approved in China. Of these, the BIBB-CorV and CoronaVac inactivated whole-virion vaccines were widely distributed in China and developing countries. However, the performance of the two vaccines in the real world has not been summarized. Methods: A living systematic review based on findings from ongoing post-licensure studies was conducted, applying standardized algorithms. Articles published between 1 May 2020 and 31 May 2022 in English and Chinese were searched for in Medline, Embase, WanFang Data, medRxiv, bioRxiv, arXiv, SSRN, and Research Square, using SARS-CoV-2, COVID-19, and vaccine as the MeSH terms. Studies with estimates of safety, immunogenicity, and effectiveness from receiving the BIBB-CorV or CoronaVac vaccine that met the predefined screening criteria underwent a full-text review. The Joanna Briggs Institute's Critical Appraisal Checklist and the Cochrane risk of bias were used for assessment of the quality. A random-effects meta-regression model was applied to identify the potential impact factors on the vaccines' effectiveness. Results: In total, 32578 articles were identified, of these, 770 studies underwent a full-text review. Eventually, 213 studies were included. The pooled occurrence of solicited and unsolicited adverse events after any dose of either vaccine varied between 10% and 40%. The top five commonly reported rare adverse events were immunization stress-related responses (211 cases, 50.0%), cutaneous responses (43 cases, 10.2%), acute neurological syndrome (39 cases, 9.2%), anaphylaxis (17 cases, 4.0%), and acute stroke (16 cases, 3.8%). The majority (83.3%) recovered or were relieved within several days. The peak neutralization titers against the ancestral strain was found within 1 month after the completion of the primary series of either vaccine, with a GMT (geometric mean titer) of 43.7 (95% CI: 23.2-82.4), followed by a dramatic decrease within 3 months. At Month 12, the GMT was 4.1 (95% CI: 3.8-4.4). Homologous boosting could restore humoral immunity, while heterologous boosting elicited around sixfold higher neutralization titers in comparison with homologous boosting. The effectiveness of receiving either vaccine against death and severe disease was around 85% for both shortly after the primary series. At Month 12, the protection against death did not decline, while the protection against severe disease decreased to ~75%. Conclusions: Both the BIBP-CorV and CoronaVac inactivated vaccines are safe. Sustained vaccine effectiveness against death was determined 12 months after the primary series, although protection against severe disease decreased slightly over time. A booster dose could strengthen the waning effectiveness; however, the duration of the incremental effectiveness and the additional benefit provided by a heterologous booster need to be studied.

DGCPPISP: a PPI site prediction model based on dynamic graph convolutional network and two-stage transfer learning.

BACKGROUND: Proteins play a pivotal role in the diverse array of biological processes, making the precise prediction of protein-protein interaction (PPI) sites critical to numerous disciplines including biology, medicine and pharmacy. While deep learning methods have progressively been implemented for the prediction of PPI sites within proteins, the task of enhancing their predictive performance remains an arduous challenge. RESULTS: In this paper, we propose a novel PPI site prediction model (DGCPPISP) based on a dynamic graph convolutional neural network and a two-stage transfer learning strategy. Initially, we implement the transfer learning from dual perspectives, namely feature input and model training that serve to supply efficacious prior knowledge for our model. Subsequently, we construct a network designed for the second stage of training, which is built on the foundation of dynamic graph convolution. CONCLUSIONS: To evaluate its effectiveness, the performance of the DGCPPISP model is scrutinized using two benchmark datasets. The ensuing results demonstrate that DGCPPISP outshines competing methods in terms of performance. Specifically, DGCPPISP surpasses the second-best method, EGRET, by margins of 5.9%, 10.1%, and 13.3% for F1-measure, AUPRC, and MCC metrics respectively on Dset_186_72_PDB164. Similarly, on Dset_331, it eclipses the performance of the runner-up method, HN-PPISP, by 14.5%, 19.8%, and 29.9% respectively.

Elucidating the influence and mechanism of different phenols on the properties, food quality and function of maize starch.

This study discusses interaction differences between three phenols (protocatechuic acid, naringin and tannic acid) and starch helix, investigates influences of phenols at different doses on properties of maize starch, and further determines their effects on quality and function of maize-starchy foods. Simulated results indicate variations of phenolic structure (phenolic hydroxyl group amount, glycoside structure and steric hindrance) and dose induce phenols form different complexes with starch helix. Formation of different starch-phenols complexes alters gelatinization (1.65-5.63 J/g), pasting form, water binding capacity (8.83-12.69 g/g) and particle size distribution of starch. Meanwhile, differences in starch-phenols complexes are reflected in fingerprint area (R1045/1022: 0.920 to 1.047), crystallinity (8.3% to 17.0%), rheology and gel structure of starch. Additionally, phenols change texture and color of cold maize cake, giving them different antioxidant capacity and lower digestibility. Findings are beneficial for understanding interaction between starch and different phenols and their potential application.

Comparison of simulation and predictive efficacy for hemorrhagic fever with renal syndrome incidence in mainland China based on five time series models.

Background: Hemorrhagic fever with renal syndrome (HFRS) is a zoonotic infectious disease commonly found in Asia and Europe, characterized by fever, hemorrhage, shock, and renal failure. China is the most severely affected region, necessitating an analysis of the temporal incidence patterns in the country. Methods: We employed Autoregressive Integrated Moving Average (ARIMA), Long Short-Term Memory (LSTM), Convolutional Neural Network (CNN), Nonlinear AutoRegressive with eXogenous inputs (NARX), and a hybrid CNN-LSTM model to model and forecast time series data spanning from January 2009 to November 2023 in the mainland China. By comparing the simulated performance of these models on training and testing sets, we determined the most suitable model. Results: Overall, the CNN-LSTM model demonstrated optimal fitting performance (with Root Mean Square Error (RMSE), Mean Absolute Percentage Error (MAPE), and Mean Absolute Error (MAE) of 93.77/270.66, 7.59%/38.96%, and 64.37/189.73 for the training and testing sets, respectively, lower than those of individual CNN or LSTM models). Conclusion: The hybrid CNN-LSTM model seamlessly integrates CNN's data feature extraction and LSTM's recurrent prediction capabilities, rendering it theoretically applicable for simulating diverse distributed time series data. We recommend that the CNN-LSTM model be considered as a valuable time series analysis tool for disease prediction by policy-makers.

Elucidating effects of Epiphyllum oxypetalum (DC.) Haw polysaccharide on the physicochemical and digestive properties of tapioca starch.

Effects of Epiphyllum oxypetalum (DC.) Haw polysaccharide (EP) on physicochemical/digestive properties of tapioca starch (TS) were investigated, and its effects on final quality of TS-based foods were further determined. Results showed EP significantly decreased gelatinization enthalpy (3.92 to 2.11 J/g) and increased breakdown (302 to 382 cp), thereby inducing the gelatinization of TS. Meanwhile, EP decreased setback viscosity (324 to 258 cp), suggesting the retrogradation of TS paste was inhibited. Rheological determination results suggested EP had an impact on the viscoelasticity of TS paste. Moreover, particle size distribution showed EP increased size of TS by cross-linking. Additionally, the suitable addition of EP ameliorated the microstructure and decreased the crystal diffraction peak area of TS gel. Infrared spectroscopy results revealed EP modified the above properties of TS by hydrogen bonds and non-covalent forces. Furthermore, EP inhibited the in vitro digestion of TS paste. Using taro balls as TS-based food model, appropriate addition of EP (0.10 %) improved texture properties, frozen storage stability and color of samples. The present results can not only facilitate the understanding of the modification mechanism of EP on the properties of TS, but also induce the burgeoning of starchy products and the possible application of EP in foods.

Trend analysis and prediction of gonorrhea in mainland China based on a hybrid time series model.

BACKGROUND: Gonorrhea has long been a serious public health problem in mainland China that requires attention, modeling to describe and predict its prevalence patterns can help the government to develop more scientific interventions. METHODS: Time series (TS) data of the gonorrhea incidence in China from January 2004 to August 2022 were collected, with the incidence data from September 2021 to August 2022 as the validation. The seasonal autoregressive integrated moving average (SARIMA) model, long short-term memory network (LSTM) model, and hybrid SARIMA-LSTM model were used to simulate the data respectively, the model performance were evaluated by calculating the mean absolute percentage error (MAPE), root mean square error (RMSE), and mean absolute error (MAE) of the training and validation sets of the models. RESULTS: The Seasonal components after data decomposition showed an approximate bimodal distribution with a period of 12 months. The three models identified were SARIMA(1,1,1) (2,1,2)12, LSTM with 150 hidden units, and SARIMA-LSTM with 150 hidden units, the SARIMA-LSTM model fitted best in the training and validation sets, for the smallest MAPE, RMSE, and MPE. CONCLUSIONS: The overall incidence trend of gonorrhea in mainland China has been on the decline since 2004, with some periods exhibiting an upward trend. The incidence of gonorrhea displays a seasonal distribution, typically peaking in July and December each year. The SARIMA model, LSTM model, and SARIMA-LSTM model can all fit the monthly incidence time series data of gonorrhea in mainland China. However, in terms of predictive performance, the SARIMA-LSTM model outperforms the SARIMA and LSTM models, with the LSTM model surpassing the SARIMA model. This suggests that the SARIMA-LSTM model can serve as a preferred tool for time series analysis, providing evidence for the government to predict trends in gonorrhea incidence. The model's predictions indicate that the incidence of gonorrhea in mainland China will remain at a high level in 2024, necessitating that policymakers implement public health measures in advance to prevent the spread of the disease.

Hemispheric lateralization and top-down regulation of the prefrontal cortex on sequential memory of familiar faces.

Working memory of familiar faces involves the coordination of multiple brain regions in sensory processing, attention and memory, and relies on robust representations in long-term memory. It is not clear how prior knowledge interacts with bottom-up visual processing at different phases of working memory. In this study, we collected functional magnetic resonance imaging (fMRI) data of 40 right-handed participants during the sequential memory task and recognition task of familiar celebrity faces. We observed strong left-lateralized neural activity in the language-processing areas and right-lateralized activity for visual processing in the dorsal stream. Yet, no obvious hemispheric lateralization was found in either face-selective (fusiform gyrus) or memory-specific (hippocampus) areas. Besides, the left lateralization of prefrontal activity and its task-evoked regulation on visual areas boost face memory performance, i.e., faster reaction and higher accuracy. These findings suggest that the top-down prefrontal regulation plays a critical role in the successful memory of familiar faces. Our study provides neural substrates underlying how familiarity boosts face memory by endorsing prior/common knowledge through left-lateralized language network.

High-sensitivity force sensing using a phonon laser in an active levitated optomechanical system.

Force detection with high sensitivity is of paramount importance in many fields of study, from gravitational wave detection to investigations of surface forces. Here, we propose and demonstrate a force-sensing method based on gain-enhanced nonlinearity in a nonlinear phonon laser. Experimental and simulation results show that the input force leads to the frequency shift of phonon laser, due to nonlinearity. In addition, we further investigate the influences of the pumping power, numerical aperture, and microsphere's refractive index on the performance of this force-sensing system, regarding the sensitivity and the linear response range. Our work paves a new way towards the realization of precise metrology based on the nonlinearity of phonon laser.

Inactivated SARS-CoV-2 Vaccine Booster Against Omicron Infection Among Quarantined Close Contacts.

Importance: Assessment of additional protection of a booster dose with an inactivated SARS-CoV-2 vaccine is key to developing vaccination strategies for billions of people worldwide who have received the primary 2-dose regimen. Objective: To estimate the relative effectiveness of a booster dose of an inactivated SARS-CoV-2 vaccine against Omicron infection. Design, Setting, and Participants: This cohort study was conducted among primary close contacts without previous SARS-CoV-2 infection identified in Shenzhen, China, between February and October 2022. Multiple strict nucleic acid testing and symptom surveillance for SARS-CoV-2 infection were regularly conducted during the 7-day centralized plus 7-day home-based quarantine. Exposure: A booster with an inactivated SARS-CoV-2 vaccine vs no booster after receipt of the primary 2-dose inactivated SARS-CoV-2 vaccine regimen. Main Outcomes and Measures: The primary outcomes were overall, symptomatic, and asymptomatic infections. Secondary outcomes were length of incubation and level of cycle threshold values. All the outcomes were assessed during the quarantine period. Results: Among 119 438 eligible participants (mean [SD] age, 37.6 [12.0] years; 66 201 men [55.4%]), 86 251 (72.2%) received a booster dose of an inactivated SARS-CoV-2 vaccine and 33 187 (27.8%) did not. A total of 671 cases infected with Omicron BA.2 were confirmed (464 symptomatic and 207 asymptomatic), and no severe infection or death events were observed. At a median (IQR) duration of 111 (75 to 134) days after booster vaccination, the relative effectiveness of a booster was 32.2% (95% CI, 11.3% to 48.2%) for overall infection, 23.8% (95% CI, -8.2% to 46.4%) for symptomatic infection, and 43.3% (95% CI, 12.3% to 63.3%) for asymptomatic infection. The effectiveness against overall infection changed nonlinearly over time following booster vaccination: 44.9% (95% CI, 4.9% to 68.1%) within 60 days, 50.4% (95% CI, 23.7% to 67.7%) at 61 to 120 days, 29.1% (95% CI, -4.8% to 52.1%) at 121 to 180 days, and 19.4% (95% CI, -14.4% to 43.2%) after 180 days (nonlinear P = .03). The effectiveness did not vary significantly according to the interval between booster vaccination and completion of primary vaccination. There was no association of booster vaccination with incubation or cycle threshold values. Conclusions and Relevance: In this cohort study, a booster dose of an inactivated SARS-CoV-2 vaccine provided additional moderate protection against mild infection for 120 days after receipt, but more research is needed to determine the optimal timing of a booster and its effectiveness in preventing severe infection for a longer duration.

Short-term effect of coil handle orientations on fMRI-guided rTMS on insomnia: A case report.

Introduction: The coil handle orientation plays a pivotal role in the therapeutic efficacy of repetitive transcranial magnetic stimulation (rTMS). However, there is currently no consensus on the optimal individualized coil handle orientation, especially for non-motor areas. Case presentation: The present case reported a short-term effect of functional connectivity (FC)-guided rTMS with coil handle posterior-anterior 45° (PA45°) and posterior-anterior 135° (PA135°) on a patient with insomnia. Notably, in this case, the PA45° orientation was nearly perpendicular to the adjacent sulcus, while the PA135° orientation was almost parallel to it. Local brain activity and functional connectivity were assessed using resting-state functional magnetic resonance imaging (RS-fMRI). Additionally, motor evoked potentials (MEPs) were captured both pre and post-rTMS sessions. Findings: The coil handle orientation PA45° outperformed the PA135° in both RS-fMRI and MEP outcomes. Moreover, a 9-day rTMS treatment led to discernible improvements in symptoms of depression and anxiety, complemented by a modest enhancement in sleep quality.

Characteristics of the phonon laser in the active levitated optomechanical system.

Phonon lasers, coherent oscillations of phonons, have gradually become one of the emerging frontiers in the last decades, and have promising applications in quantum sensing, information processing, and precise measurement. Recently, phonon lasers based on dissipative coupling have been realized in an active levitated optomechanical (LOM) system for the first time. Here, we further investigated the characteristics of the phonon laser in the system above regarding the oscillator amplitude and the phonon laser linewidth. We established both the experimental system and a physical model of the phonon laser. On the basis of simulations and experiments, the influences of pumping power, numerical aperture, the microsphere's diameter and refractive index on the performance of the phonon lasers are sufficiently discussed. Our work is of great significance for the high-quality phonon lasers generated by the appropriate parameters, which is the basis for the in-depth research and practical application.

Abnormal individualized peak functional connectivity toward potential repetitive transcranial magnetic stimulation treatment of autism spectrum disorder.

Functional connectivity (FC) derived from resting-state functional magnetic resonance imaging has been widely applied to guide precise repetitive transcranial magnetic stimulation (rTMS). The left, right, and bilateral dorsolateral prefrontal cortices (DLPFC) have been used as rTMS treatment target regions for autism spectrum disorder (ASD), albeit with moderate efficacy. Thus, we aimed to develop an individualized localization method for rTMS treatment of ASD. We included 266 male ASDs and 297 male typically-developed controls (TDCs) from the Autism Brain Imaging Data Exchange Dataset. The nucleus accumbens (NAc) was regarded as a promising effective region, which was used as a seed and individualized peak FC strength in the DLPFC was compared between ASD and TDC. Correlation analysis was conducted between individualized peak FC strength and symptoms in ASD. We also investigated the spatial distribution of individualized peak FC locations in the DLPFC and conducted voxel-wise analysis to compare NAc-based FC between the two groups. ASD showed stronger peak FC in the right DLPFC related to TDC (Cohen's d = -.19, 95% CI: -0.36 to -0.03, t = -2.30, p = .02). Moreover, negative correlation was found between the peak FC strength in the right DLPFC and Autism Diagnostic Observation Schedule (ADOS) scores, which assessed both the social communication and interaction (r = -.147, p = .04, uncorrected significant), and stereotyped behaviors and restricted interests (r = -.198, p = .02, corrected significant). Peak FC locations varied substantially across participants. No significant differences in NAc-based FC in the DLPFC were found in the voxel-wise comparison. Our study supports the use of individualized peak FC-guided precise rTMS treatment of male ASD. Moreover, stimulating the right DLPFC might alleviate core symptoms of ASD.

Attitudes Regarding Influenza Vaccination Among Public Health Workers during COVID-19 Pandemic - China, September 2022.

What is already known about this topic?: Public health workers (PHWs) were listed as a priority group recommended for influenza vaccination during the coronavirus disease 2019 (COVID-19) pandemic. Understanding the drivers of influenza vaccine hesitancy among PHWs can promote influenza vaccination in the COVID-19 pandemic. What is added by this report?: The study found that 10.7% of PHWs were hesitant to get an influenza vaccination. Drivers associated with vaccine hesitancy were assessed based on "3Cs model." The absence of a government or workplace requirement and concerns about vaccine safety were the biggest obstacles for PHWs to recommend influenza vaccination. What are the implications for public health practice?: Interventions are needed to improve PHWs' influenza vaccine coverage to prevent the co-circulation of influenza and COVID-19.

Efficacy of SARS-CoV-2 vaccines and the dose-response relationship with three major antibodies: a systematic review and meta-analysis of randomised controlled trials.

BACKGROUND: The efficacy of SARS-CoV-2 vaccines in preventing severe COVID-19 illness and death is uncertain due to the rarity of data in individual trials. How well the antibody concentrations can predict the efficacy is also uncertain. We aimed to assess the efficacy of these vaccines in preventing SARS-CoV-2 infections of different severities and the dose-response relationship between the antibody concentrations and efficacy. METHODS: We did a systematic review and meta-analysis of randomised controlled trials (RCTs). We searched PubMed, Embase, Scopus, Web of Science, Cochrane Library, WHO, bioRxiv, and medRxiv for papers published between Jan 1, 2020 and Sep 12, 2022. RCTs on the efficacy of SARS-CoV-2 vaccines were eligible. Risk of bias was assessed using the Cochrane tool. A frequentist, random-effects model was used to combine efficacy for common outcomes (ie, symptomatic and asymptomatic infections) and a Bayesian random-effects model was used for rare outcomes (ie, hospital admission, severe infection, and death). Potential sources of heterogeneity were investigated. The dose-response relationships of neutralising, spike-specific IgG and receptor binding domain-specific IgG antibody titres with efficacy in preventing SARS-CoV-2 symptomatic and severe infections were examined by meta-regression. This systematic review is registered with PROSPERO, CRD42021287238. FINDINGS: 28 RCTs (n=286 915 in vaccination groups and n=233 236 in placebo groups; median follow-up 1-6 months after last vaccination) across 32 publications were included in this review. The combined efficacy of full vaccination was 44·5% (95% CI 27·8-57·4) for preventing asymptomatic infections, 76·5% (69·8-81·7) for preventing symptomatic infections, 95·4% (95% credible interval 88·0-98·7) for preventing hospitalisation, 90·8% (85·5-95·1) for preventing severe infection, and 85·8% (68·7-94·6) for preventing death. There was heterogeneity in the efficacy of SARS-CoV-2 vaccines against asymptomatic and symptomatic infections but insufficient evidence to suggest whether the efficacy could differ according to the type of vaccine, age of the vaccinated individual, and between-dose interval (p>0·05 for all). Vaccine efficacy against symptomatic infection waned over time after full vaccination, with an average decrease of 13·6% (95% CI 5·5-22·3; p=0·0007) per month but can be enhanced by a booster. We found a significant non-linear relationship between each type of antibody and efficacy against symptomatic and severe infections (p<0·0001 for all), but there remained considerable heterogeneity in the efficacy, which cannot be explained by antibody concentrations. The risk of bias was low in most studies. INTERPRETATION: The efficacy of SARS-CoV-2 vaccines is higher for preventing severe infection and death than for preventing milder infection. Vaccine efficacy wanes over time but can be enhanced by a booster. Higher antibody titres are associated with higher estimates of efficacy but precise predictions are difficult due to large unexplained heterogeneity. These findings provide an important knowledge base for interpretation and application of future studies on these issues. FUNDING: Shenzhen Science and Technology Programs.

Analysis of a Sabin-Strain Inactivated Poliovirus Vaccine Response to a Circulating Type 2 Vaccine-Derived Poliovirus Event in Sichuan Province, China 2019-2021.

Importance: The Sabin-strain inactivated poliovirus vaccine (IPV) may be a tool for polio outbreak response in certain situations. Objective: To investigate the response to a type 2 vaccine-derived poliovirus (VDPV2) outbreak. Design, Setting, and Participants: This case series was conducted in China after a VDPV2 was detected in stool specimens from a child with acute flaccid paralysis (AFP) in Sichuan Province in 2019, 3 years after the global withdrawal of live, attenuated type 2 oral poliovirus vaccine (OPV). Investigation followed National Health Commission and World Health Organization guidance and included searching hospitals for unreported AFP cases; testing stool specimens from the child, his contacts, and local children; enhanced environmental surveillance for VDPV2s in wastewater; and measuring vaccination coverage. Sabin-strain IPV campaigns were conducted in a wide geographic area. Main Outcomes and Measures: Any VDPV2 detection after completion of the supplementary immunization activities. Results: A 28-nucleotide-change VDPV2 was isolated from a young boy. Three VDPV2s were detected in healthy children; 2 were contacts of the original child, and none had paralysis. A search of 31 million hospital records found 10 unreported AFP cases; none were polio. No type 2 polioviruses were found in wastewater. Prior to the event, polio vaccine coverage was 65% among children younger than 5 years. Sabin-strain IPV campaigns reached more than 97% of targeted children, administering 1.4 million doses. No transmission source was identified. More than 1 year of enhanced poliovirus environmental and AFP surveillance detected no additional VDPVs. Conclusions and Relevance: These findings suggest that the circulating VPDV2 outbreak in 2019 was associated with low vaccine coverage. An investigation discovered 3 infected but otherwise healthy children and no evidence of the virus in wastewater. Following Sabin-strain IPV-only campaigns expanding from county to prefecture, the poliovirus was not detected, and the outbreak response was considered by an expert panel and the World Health Organization to have been successful. This success suggests that the Sabin-strain IPV may be a useful tool for responding to circulating VDPV2 outbreaks when high-quality supplementary immunization activities can be conducted and carefully monitored in settings with good sanitation.