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PubMed; 2021.
Preprint in English | PubMed | ID: ppcovidwho-333832


BACKGROUND: As SARS-CoV-2 vaccination coverage increases in the United States (US), there is a need to understand the real-world effectiveness against severe Covid-19 and among people at increased risk for poor outcomes. METHODS: In a multicenter case-control analysis of US adults hospitalized March 11 - May 5, 2021, we evaluated vaccine effectiveness to prevent Covid-19 hospitalizations by comparing odds of prior vaccination with an mRNA vaccine (Pfizer-BioNTech or Moderna) between cases hospitalized with Covid-19 and hospital-based controls who tested negative for SARS-CoV-2. RESULTS: Among 1210 participants, median age was 58 years, 22.8% were Black, 13.8% were Hispanic, and 20.6% had immunosuppression. SARS-CoV-2 lineage B.1.1.7 was most common variant (59.7% of sequenced viruses). Full vaccination (receipt of two vaccine doses >=14 days before illness onset) had been received by 45/590 (7.6%) cases and 215/620 (34.7%) controls. Overall vaccine effectiveness was 86.9% (95% CI: 80.4 to 91.2%). Vaccine effectiveness was similar for Pfizer-BioNTech and Moderna vaccines, and highest in adults aged 18-49 years (97.3%;95% CI: 78.9 to 99.7%). Among 45 patients with vaccine-breakthrough Covid hospitalizations, 44 (97.8%) were >=50 years old and 20 (44.4%) had immunosuppression. Vaccine effectiveness was lower among patients with immunosuppression (59.2%;95% CI: 11.9 to 81.1%) than without immunosuppression (91.3%;95% CI: 85.5 to 94.7%). CONCLUSION: During March-May 2021, SARS-CoV-2 mRNA vaccines were highly effective for preventing Covid-19 hospitalizations among US adults. SARS-CoV-2 vaccination was beneficial for patients with immunosuppression, but effectiveness was lower in the immunosuppressed population.

Epidemiol Infect ; 148: e267, 2020 08 14.
Article in English | MEDLINE | ID: covidwho-912841


Previous research on respiratory infection transmission among university students has primarily focused on influenza. In this study, we explore potential transmission events for multiple respiratory pathogens in a social contact network of university students. University students residing in on-campus housing (n = 590) were followed for the development of influenza-like illness for 10-weeks during the 2012-13 influenza season. A contact network was built using weekly self-reported contacts, class schedules, and housing information. We considered a transmission event to have occurred if students were positive for the same pathogen and had a network connection within a 14-day period. Transmitters were individuals who had onset date prior to their infected social contact. Throat and nasal samples were analysed for multiple viruses by RT-PCR. Five viruses were involved in 18 transmission events (influenza A, parainfluenza virus 3, rhinovirus, coronavirus NL63, respiratory syncytial virus). Transmitters had higher numbers of co-infections (67%). Identified transmission events had contacts reported in small classes (33%), dormitory common areas (22%) and dormitory rooms (17%). These results suggest that targeting person-to-person interactions, through measures such as isolation and quarantine, could reduce transmission of respiratory infections on campus.

Respiratory Tract Infections/virology , Social Networking , Students , Virus Diseases/transmission , Coinfection/virology , Female , Housing , Humans , Male , Michigan , Respiratory Tract Infections/transmission , Universities
Viral Infections of Humans ; 2020.
Article in English | PMC | ID: covidwho-848199


Coronaviruses of humans were first identified more than 60 years ago from individuals with respiratory infections, mainly mild. Two different viruses, 229E and OC43 were initially recognized. Because of difficulty in isolating them using standard techniques, many of the early studies of their occurrence were seroepidemiologic. They were confirmed to be worldwide in distribution, and, in the North Temperate Zone, mainly occurring in the winter season. With the development of the reverse transcriptase polymerase chain reaction (PCR) technique, two additional distinct viruses have been identified, HKU1 and NL63. The four viruses have now been recognized as important in the etiology of common respiratory infections, second only to the rhinoviruses.In 2002, a previously unrecognized betacoronavirus emerged from a zoonotic reservoir in Southern China and spread during the following year to several major cities of the world. The resulting illness was termed Severe Acute Respiratory Syndrome (SARS) because of its potential lethality. More than 8,000 probable cases were reported during 2003, mainly from Hong Kong and mainland China, producing social and economic disruption in those areas affected. A constant feature of the outbreak was the importance of nosocomial spread. In spite of an estimated basic reproductive number higher than influenza, the outbreak was ended, in large part because of control of in-hospital transmission. In 2012, another betacoronavirus has emerged in the Arabian peninsula which is producing a somewhat similar illness, termed Middle East Respiratory Syndrome (MERS), also marked by extensive nosocomial transmission. The outcome of this emergence is currently unknown. FAU - Monto, Arnold S.