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Background: In many settings, a large fraction of the population has both been vaccinated against and infected by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Hence, quantifying the protection provided by post-infection vaccination has become critical for policy. We aimed to estimate the protective effect against SARS-CoV-2 reinfection of an additional vaccine dose after an initial Omicron variant infection. Methods: We report a retrospective, population-based cohort study performed in Shanghai, China, using electronic databases with information on SARS-CoV-2 infections and vaccination history. We compared reinfection incidence by post-infection vaccination status in individuals initially infected during the April–May 2022 Omicron variant surge in Shanghai and who had been vaccinated before that period. Cox models were fit to estimate adjusted hazard ratios (aHRs). Results: 275,896 individuals were diagnosed with real-time polymerase chain reaction-confirmed SARS-CoV-2 infection in April–May 2022; 199,312/275,896 were included in analyses on the effect of a post-infection vaccine dose. Post-infection vaccination provided protection against reinfection (aHR 0.82; 95% confidence interval 0.79–0.85). For patients who had received one, two, or three vaccine doses before their first infection, hazard ratios for the post-infection vaccination effect were 0.84 (0.76–0.93), 0.87 (0.83–0.90), and 0.96 (0.74–1.23), respectively. Post-infection vaccination within 30 and 90 days before the second Omicron wave provided different degrees of protection (in aHR): 0.51 (0.44–0.58) and 0.67 (0.61–0.74), respectively. Moreover, for all vaccine types, but to different extents, a post-infection dose given to individuals who were fully vaccinated before first infection was protective. Conclusions: In previously vaccinated and infected individuals, an additional vaccine dose provided protection against Omicron variant reinfection. These observations will inform future policy decisions on COVID-19 vaccination in China and other countries. Funding: This study was funded the Key Discipline Program of Pudong New Area Health System (PWZxk2022-25), the Development and Application of Intelligent Epidemic Surveillance and AI Analysis System (21002411400), the Shanghai Public Health System Construction (GWVI-11.2-XD08), the Shanghai Health Commission Key Disciplines (GWVI-11.1-02), the Shanghai Health Commission Clinical Research Program (20214Y0020), the Shanghai Natural Science Foundation (22ZR1414600), and the Shanghai Young Health Talents Program (2022YQ076).

Seasonal influenza remains a significant public health concern globally, with annual vaccinations as the most effectively preventive measure. This study examines influenza vaccination coverage rates across different age groups in Pudong New Area, Shanghai, China, from 2013 to 2023. This study extracted influenza vaccination data from the Shanghai Immunization Planning Information System (SIPIS) of the Center for Disease Control and Prevention Shanghai’s Pudong New Area from 2013 to 2023. The analysis utilized weighted linear regression to compare vaccination rates over the study period. From 2013 to 2023, a cumulative total of 1,421,295 influenza vaccinations were administered in Pudong New Area, with the quadrivalent inactivated influenza vaccines (IIV4) and trivalent inactivated influenza vaccines (IIV3) comprising 56.8% and 42.9%, respectively. The overall average influenza vaccine coverage rate was 2.27% (95% CI: 2.26, 2.28). The 0–4 years group exhibited the highest average annual coverage rate of 22.52% (95% CI: 22.47, 22.57) among different age groups, in stark contrast to that of the 20–24 years age group, which had the lowest at 0.32% (95% CI: 0.31, 0.33). In terms of repeat vaccinations, a significant majority (86.87%) of recipients received only 1–2 doses, while just 13.13% received 3 or more doses. Although influenza vaccination coverage among preschool children in Pudong New Area is relatively high, it falls significantly short of WHO recommendations. Enhance the level of awareness of influenza vaccine among adults and provide a free influenza vaccination strategy for specific groups such as doctors, which is helpful to increase influenza vaccination rates among populations.

Background: A 2-dose varicella vaccination strategy has been implemented in Shanghai, China since 2018. This study aims to analyze the epidemiological characteristics of breakthrough varicella cases and to evaluate the incremental effectiveness of the 2-dose varicella vaccination among Chinese children. Methods: A retrospective investigation was conducted among native children born between 2015 and 2019 in the Pudong New area of Shanghai, China. From 2016 to 2023, demographic information and data regarding varicella vaccination were collected through the Shanghai Immunization Information System, while information on varicella infections was obtained from the China Information System for Disease Control and Prevention. The incremental vaccine effectiveness (VE) for varicella was defined as (1 − relative risk (RR)) × 100%, where RRs were calculated based on the rate of varicella infections. Results: A total of 519,951 local children were enrolled in the cohort analysis. The overall rate of breakthrough varicella infections was found to be 0.25%, corresponding to 1182 cases. Specifically, the rates of breakthrough varicella infections for individuals who received 1-dose and 2-dose VarV were 0.39% (977 cases) and 0.10% (205 cases), respectively. The average ages of onset for these infections were 2.13 ± 0.99 years and 5.52 ± 1.18 years, respectively. Furthermore, the breakthrough varicella infection rate among individuals born between 2015 and 2019 exhibited a decline, decreasing from 0.52% to 0.26% for those who received one dose of VarV, and from 0.23% to 0.01% for those who received two doses. The VE against all varicella was 85% (95% confidence interval: 84–86) for one dose and 96% (95% confidence interval: 96–97) for two doses, and the incremental VE was 75% (95% confidence interval: 71–79) compared with 1-dose. Conclusions: the 2-dose VarV vaccination strategy provided excellent protection to prevent varicella, and the universal 2-dose regimen of the varicella vaccine should be recommended to prevent varicella disease among children in China.

The aim of this study was to investigate the level of inactivated A71 (EV-A71) vaccination in Pudong New Area of Shanghai and its effects on the epidemiology and pathogen spectrum of hand–foot–mouth disease (HFMD) in this area, as well as to provide a basis for improving the prevention and control strategy of HFMD in this area. Data were collected from the “Comprehensive Management Cloud Platform for Immunization Program” system from December 2016 to December 2022. The data on HFMD cases from January 2012 to December 2022 were extracted from the “China Information System for Disease Control and Prevention”. A total of 484,056 doses were administered. The vaccination rate of the first dose was 14.03%, and the full vaccination rate was 13.33%. There were significant differences between the first dose and the full vaccination rate in different years (χ2 = 46,538.831, p < 0.001, χ2 = 50,013.946, p < 0.001). A total of 91625 cases of HFMD were reported, including 58 severe cases, and no deaths. Before and after the administration of the inactivated EV-A71 vaccine, there were statistical differences in the distribution of HFMD cases in terms of gender, household registration, occupation, and age (p < 0.001). The etiological surveillance results showed that the rate of enterovirus positivity was 84.15%, with 9.85% being EV-A71, 23.74% CV-A16, and 50.56% non-EV-A71 and non-CV-A16. The coverage rate of the inactivated EV-A71 vaccine in Pudong New Area was not high, and the incidence of HFMD showed a downward trend after the postmarketing of the vaccine. The majority of HFMD infections were non-EV-A71 and non-CV-A16, with CV-A6 accounting for the highest proportion. It is recommended to accelerate the development of combined vaccines to provide more antibody protection.

ObjectiveTo examine vaccination status of recombinant coronavirus disease 2019 (COVID-19) vaccine (adenovirus type 5 vector) (Ad5-nCoV) and to evaluate the safety of Ad5-nCoV vaccination in Pudong New Area of Shanghai during a period of COVID-19 epidemic for providing evidence to Ad5-nCoV mass vaccination. MethodsThe data on Ad5-nCoV mass vaccination and on reported adverse events following immunization (AEFI) related to the vaccination in Pudong New Area of Shanghai from May 2021 through February 2022 were extracted from Shanghai Municipal Vaccination Registry Information System and from China Information System for Disease Control and Prevention. Descriptive statistics was performed on the data collected. ResultsDuring the 10-month period in the district, totally 246 913 doses of Ad5-nCoV were administrated and 198 AEFI were registered, with a reported AEFI incidence rate of 80.190/100 000 doses. Of all the reported AEFI, 151 (76.26%) were common adverse reactions, followed by 36 (18.18%) of coincidental events and 9 (4.55%) of psychogenic reactions, and only 2 (1.01%) rare adverse reactions were reported. The reported AEFI incidence rate was the lowest among the vaccinees aged 50 – 92 years. Higher reported AEFI rate was observed among the female vaccinees than that among the male vaccinees (112.29 vs. 66.47 per 100 000 doses) and the reported AEFI rate was higher in the vaccinees having the first dose Ad5-nCoV than that in those having the booster dose (89.03 vs. 25.10 per 100 000 doses). Almost all (93.94% , n =186) of the reported AEFI occurred during the day of the vaccination. ConclusionThe reported incidence of Ad5-nCoV-related AEFI was higher than that of inactivated COVID-19 vaccine but lower than that of influenza vaccine in the mass vaccination during a COVID-19 epidemic in a district of Shanghai city, suggesting that the AEFI incidence of recombinant novel coronavirus vaccination was within the safety range.

Children with hematological malignancies are at increased risk of hepatitis B virus infection. This study assessed the immunogenicity and safety profile of HBV vaccination in pediatric hemato-oncological children. A nonrandomized interventional study was conducted from January 2017 to February 2020 in Shanghai, China. Seventy-three pediatric hemato-oncological children with hepatitis B surface antibody (anti-HBs) titers

Emergency vaccination (EV) is used as effective postexposure prophylaxis (PEP) to control varicella outbreaks within 3–5 days. However, the advantages of a second dose of varicella vaccine (VarV) in students who had received one dose before an outbreak and the potential benefits of EV at more than 5 days after exposure have not been fully evaluated. This study evaluated the vaccine effectiveness (VE) of EV in preventing disease development during a varicella outbreak in Shanghai, China, in 2020. Questionnaires were used to obtain student demographic information, clinical manifestations, varicella history, vaccination status, and willingness to receive EV. The VE of EV was calculated as [1-relative risk (RR)] ×100%. Among the 1455 students included in this study, 31 cases were identified, resulting in an overall attack rate of 2.13%. There were 6 cases in unvaccinated students and 25 cases in one-dose-vaccinated students. A total of 788 students received one EV dose. The attack rates were 6.38% (6/94), 4.26% (19/446), 2.82% (2/71), and 0.56% (4/717) among unvaccinated students, students who received 1 dose of VarV, and students who received EV with the 1st and 2nd dose of VarV, respectively. Compared to that in unvaccinated students, the VE of EV with the 2nd dose of VarV was 88% (95% CI 49% to 97%). EV should be performed as soon as possible after exposure. Nevertheless, vaccination is still recommended at more than 5 days post exposure to control varicella outbreaks.

Reinfection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants due to immune escape is challenging for the global response to the pandemic. We estimated the Omicron reinfection prevalence among people who had a previous SARS-CoV-2 infection in Shanghai, China. We conducted a telephone survey in December 2022 with those who had previously been infected with Omicron between March and May 2022. Information on their demographics, coronavirus disease 2019 (COVID-19) testing, and vaccination history was collected. The overall and subgroup reinfection rates were estimated and compared. Among the 1981 respondents who were infected between March and May 2022, 260 had positive nucleic acid or rapid antigen tests in December 2022, with an estimated reinfection rate of 13.1% (95% confidence interval [95% CI]: 11.6–14.6). The reinfection rate for those who had a booster vaccination was 11.4% (95% CI: 9.2–13.7), which was significantly lower than that for those with an incomplete vaccination series (15.2%, 95% CI: 12.3–18.1) (adjusted odds ratio [aOR]: 0.579; 95% CI: 0.412–0.813). Reinfection with the Omicron variant was lower among individuals with a previous SARS-CoV-2 infection and those who had a booster vaccination, suggesting that hybrid immunity may offer protection against reinfection with Omicron sublineages.

Abstract Background Norovirus (NoV), a member of the Caliciviridae, is now recognized as the leading cause of acute gastroenteritis (AGE) worldwide. Globally, the GII.4 Sydney_2012 variant has predominated in NoV-related AGE since 2012, although the novel variant GII.17 has also been reported as responsible for gastroenteritis outbreaks in East Asia since 2014. This study aimed to disclose the recent genotype patterns of NoV genogroup II (GII) presenting in AGE patients in Pudong New Area of Shanghai through a laboratory-based syndromic surveillance system. The study further aimed to delineate the predominant strains circulating in the population. Methods Pudong New Area is located in eastern Shanghai and covers 20.89% of the Shanghai population. The laboratory-based syndromic surveillance system is composed of 12 sentinel hospitals among the 68 general hospitals in this area. AGE patients who sought medical care were sampled following an AGE surveillance protocol. Stool samples were collected from participating patients, and a standardized questionnaire was given to each patient by trained nurses to gain information on the disease profiles and demographics of the patients. Real-time reverse transcription polymerase chain reaction (qRT-PCR) was used to screen the GI nd GII NoV and RT-PCR was used to amplify NoV GII partial capsid protein open reading frame 2 (ORF2). NoV Genotyping Tool (version 1.0, RIVM, MA Bilthoven, Netherlands) was used for genotyping, and a phylogenetic analysis was conducted by MEGA 7.0. Results During 2014–2016, among the 2069 virus-infected AGE cases, 65.88% were caused by NoV. NoV-AGE occurred most frequently in the periods from October to March. The patients with more severe diarrheal symptoms and vomiting were more likely to be infected by NoV. The main genotypes were GII.17 (44.69%) and GII.4 (39.26%), which dominated the NoV-AGE epidemics jointly or in turn, whereas a slight increase in GII.2 was observed beginning in May 2016. The GII.17 strains tended to cluster more with the Hu/JP/2014/GII.P17_GII.17/Kawasaki323 variants, representing novel prevalent strains. Among the GII.4 strains, the GII.4 Sydney_2012 variant was still the predominant strain. Conclusions NoV GII has become the main cause of virus-infected AGE in Pudong New Area, Shanghai. The predominant genotypes of NoV GII were GII.17 and GII.4. Comprehensive laboratory-based surveillance is important for clinical diagnosis and treatment. Identification of emerging new genotypes is also crucial for the prevention and control of NoV-infected AGE.

More than 30 residents and nursing assistants in a geriatric nursing hospital developed acute gastroenteritis from December 7th to December 18th, 2014 in Shanghai, China. An immediate epidemiological investigation was conducted to identify the etiological agent of the outbreak, mode of transmission and the risk factors. Cases were investigated according to an epidemiological questionnaire. Samples from cases, highly transmissible environmental surfaces and drinking water were collected for pathogens detection. A retrospective cohort study was conducted to explore the transmission mode. A total of 34 cases were affected in this acute gastroenteritis outbreak, including 23 residents, 9 nursing assistants and 2 doctors. 13 out of 30 samples were positive for GII.17 norovirus, no other pathogen was detected. Nursing assistants who developed gastroenteritis symptoms had a higher attack rate in residents they cared than those who did not develop any gastroenteritis symptoms (p

We conducted sentinel-based surveillance for norovirus in the Pudong area of Shanghai, China, during 2012–2013, by analyzing 5,324 community surveys, 408,024 medical records, and 771 laboratory-confirmed norovirus infections among 3,877 diarrhea cases. Our analysis indicated an outpatient incidence of 1.5/100 person-years and a community incidence of 8.9/100 person-years for norovirus-associated diarrhea.

Clinical and etiological characteristics of influenza-like illness (ILI) in outpatients is poorly understood in the southern temperate region of China. We conducted laboratory-based surveillance of viral etiology for ILI outpatients in Shanghai from January 2011 to December 2013.Clinical and epidemiological data from ILI outpatients, both children and adults, were collected. A total of 1970 nasopharyngeal swabs were collected and tested for 12 respiratory viruses using multiplex RT-PCR, and the data were analyzed anonymously.All 12 respiratory viruses were detected in the specimens. At least one virus was detected in 32.4% of 1970 specimens analyzed, with 1.1% showing co-infections. The most frequently detected agents were influenza A (11.7%), influenza B (9.6%), and rhinoviruses (3.1%).Other viruses were present at a frequency less than 3.0%. We observed a winter peak in the detection rate in ILI patients during 3 years of surveillance and a summer peak in 2012. HCoV, HADV, and HMPV were detected more frequently in children than in adults. Patients infected with influenza virus experienced higher temperatures, more coughs, running noses, headaches and fatigue than patients infected with other viruses and virus-free patients (p

Background: More than 200 students and teachers at a boarding school in Shanghai developed acute gastroenteritis in December, 2012. The transmission mode remained largely unknown. An immediate epidemiological investigation was conducted to identify it. Methods: Using a retrospective cohort design, we investigated demographic characteristics, school environment, and previous contacts with people who had diarrhea and/or vomiting, drinking water conditions, recalls of food consumption in the school cafeteria, hand-washing habits and eating habits. Rectal swabs of the new cases and food handlers as well as water and food samples were collected to test potential bacteria and viruses. Norovirus was detected by real-time reverse transcription-polymerase chain reaction (RT-PCR). Results: A total of 278 cases developed gastrointestinal symptoms in this outbreak, and the overall attack rate was 13.9%. The main symptoms included vomiting (50.0%), abdominal cramps (40.3%), nausea (27.0%), diarrhea (6.8%) and fever (6.8%). Twenty rectal swab samples were detected as Norovirus-positive, including 11 from student cases and 9 from asymptomatic food handlers (non-cases). Among environmental surface samples from the kitchen, 8 samples were also detected as Norovirus-positive. The genotypes of viral strains were the same (GII) in patients, asymptomatic food handlers and environmental surfaces. Other samples, including rectal swabs, water samples and food samples were negative for any bacteria and other tested viruses. Asymptomatic food handlers may have contaminated the cooked food during the food preparation. Conclusion: The study detected that the outbreak was caused by Norovirus and should be controlled by thorough disinfection and excluding asymptomatic food handlers from food preparation. Early identification of the predominant mode of transmission in this outbreak was necessary to prevent new cases. Furthermore, good hygiene practices such as regular hand washing and efficient daily disinfection should be promoted to prevent such infection and outbreaks. [ABSTRACT FROM AUTHOR]

In the winter of 2014-2015, a novel norovirus (NoV) strain (GII.17) was reported to be the major cause of gastroenteritis outbreaks in East Asia. To determine the time course of gastroenteritis infections associated with the GII.17 strain and whether GII.17 was the main epidemic strain in diarrheal patients in Shanghai, 2169 stool samples were collected and tested. The detection rate of NoV GI and GII NoV strains was 0.83 and 24.02%, respectively. Phylogenetic analysis confirmed that there were seven NoV genotypes, among which GII.4 and GII.17 were the main genotypes. The GII.17 strain was first detected in a sample collected on August 14th, 2014, and beginning in January 2015, the novel GII.17 strain replaced the GII.4 strain as the dominant NoV genotype causing acute gastroenteritis in patients in Shanghai. [ABSTRACT FROM AUTHOR]