Effectiveness of inactivated COVID-19 vaccines among older adults in Shanghai: retrospective cohort study.

We conducted a matched retrospective cohort study of two cohorts to estimate inactivated vaccine effectiveness (VE) and its comparative effectiveness of booster dose among older people in Shanghai. Cohort 1 consisted of a vaccinated group (≥1 dose) and an unvaccinated group (3,317,475 pairs), and cohort 2 consisted of a booster vaccinated group and a fully vaccinated group (2,084,721 pairs). The Kaplan-Meier method and Cox regression models were used to estimate risk and hazard ratios (HRs) study outcomes. For cohort 1, the overall estimated VEs of ≥1 dose of inactivated vaccine against SARS-CoV-2 infection, severe/critical Covid-19, and Covid-19 related death were 24.7% (95%CI 23.7%-25.7%), 86.6% (83.1%-89.4%), and 93.2% (88.0%-96.1%), respectively. Subset analysis showed that the booster vaccination provided greatest protection. For cohort 2, compared with full vaccination, relative VEs of booster dose against corresponding outcome were 16.3% (14.4%-17.9%), 60.5% (37.8%-74.9%), and 81.7% (17.5%-95.9%). Here we show, although under the scenario of persistent dynamic zero-Covid policy and non-pharmaceutical interventions, promoting high uptake of the full vaccination series and booster dose among older adults is critically important. Timely vaccination with the booster dose provided effective protection against Covid-19 outcomes.

Pathogenic characteristics of severe acute respiratory infection in adult inpatients in Yangpu District, Shanghai, 2019-2021

Objective: To understand the pathogenic spectrum and epidemiological characteristics of severe acute respiratory infection (SARI) in adult inpatients in Yangpu District, Shanghai, China, in order to explore strategies for the prevention and treatment of respiratory infectious diseases. Methods: Individual cases were from adult inpatients with SARI in Yangpu District, Shanghai, China from January 2019 to July 2021. Their respiratory samples were collected for etiological pathogen testing. Results: A total of 681 SARI cases were enrolled for sampling and lab testing. Among them, 79.00% were aged 60 years and older, and 75.48% had confirmed chronic disease history. A total of 163 infection inpatients (23.94%) were positive for at least one pathogen. The pathogens identified most frequently were influenza A virus (6.75%), followed by rhinovirus/enterovirus (3.23%), parainfluenza virus (PIV) (2.79%), Mycoplasma pneumoniae (2.35%), coronavirus (CoV) (2.06%). The positive rates of adenovirus (AdV), human metapneumovirus (hMPV), respiratory syncytial virus and bocavirus were all less than 2%. Bacterial strains were identified in eleven SARI cases, including Staphylococcus aureus and Pseudomonas aeruginosa (4 strains), Klebsiella pneumoniae (3 strains). Legionella pneumophila was detected in 9 cases (1.32%) and Bordetella pertussis in 5 cases (0.73%). Two pathogens were co-detected from 11 cases, accounting for 1.62% of 163 positive cases. The most common co-detected pathogens were influenza A virus and other pathogens, accounting for 54.55% of the mixed infection. The positive rates of pathogens were not significantly different between less than 60 years old and over 60 years old groups except for Bordetella pertussis, adenovirus and Mycoplasma pneumonia(P < 0.05). Influenza virus had epidemic peak in winter and spring, but not in summer from 2019 to 2021. Conclusion: Various respiratory pathogens are detected from adult SARI cases. It is mainly influenza virus, with co-detected pathogens and rare pathogens. This study provides helpful information for targeted prevention and control measures including vaccination.

Effectiveness of inactivated and Ad5-nCoV COVID-19 vaccines against SARS-CoV-2 Omicron BA. 2 variant infection, severe illness, and death.

BACKGROUND: Limited data are available on the effectiveness of inactivated and Ad5-nCoV COVID-19 vaccines in real-world use-especially against Omicron variants in SARS-CoV-2 infection-naïve population. METHODS: A matched case-control study was conducted among people aged ≥ 3 years between 2 December 2021 and 13 May 2022. Cases were SARS-CoV-2-infected individuals, individuals with severe/critical COVID-19, or COVID-19-related deaths. Controls were selected from consecutively test-negative individuals at the same time as cases were diagnosed and were exact-matched on year-of-age, gender, birthplace, illness onset date, and residential district in ratios of 1:1 with infected individuals and 4:1 with severe/critical COVID-19 and COVID-19-related death. Additionally, two subsets were constructed to analyze separate vaccine effectiveness (VE) of inactivated vaccines (subset 1) and Ad5-vectored vaccine (subset 2) against each of the three outcomes. RESULTS: Our study included 612,597 documented SARS-CoV-2 infections, among which 1485 progressed to severe or critical illness and 568 died. Administering COVID-19 vaccines provided limited protection against SARS-CoV-2 infection across all age groups (overall VE: 16.0%, 95% CI: 15.1-17.0%) but high protection against severe/critical illness (88.6%, 85.8-90.8%) and COVID-19-related death (91.6%, 86.8-94.6%). In subset 1, inactivated vaccine showed 16.3% (15.4-17.2%) effective against infection, 88.6% (85.8-90.9%) effective against severe/critical COVIID-19, and 91.7% (86.9-94.7%) against COVID-19 death. Booster vaccination with inactivated vaccines enhanced protection against severe COVID-19 (92.7%, 90.1-94.6%) and COVID-19 death (95.9%, 91.4-98.1%). Inactivated VE against infection began to wane 12 weeks after the last dose, but two and three doses sustained high protection levels (> 80%) against severe/critical illness and death, while subset 2 showed Ad5-vectored vaccine was 13.2% (10.9-15.5%) effective against infection and 77.9% (15.6-94.2%) effective against severe/critical COVIID-19. CONCLUSIONS: Our real-world study found high and durable two- and three-dose inactivated VE against Omicron-associated severe/critical illness and death across all age groups, but lower effectiveness against Omicron infection, which reinforces the critical importance of full-series vaccination and timely booster dose administration for all eligible individuals.

Assessment and prediction of the oversea imported risk of COVID-19 in Shanghai

Objective: To determine the association between global epidemic of COVID-19 and local situation of imported cases from abroad to Shanghai, and then to predict the risk of imported COVID-19 epidemic from December 2020 through March 2021.