ABSTRACT
BACKGROUND: Methodologically rigorous studies on Covid-19 vaccine effectiveness (VE) in preventing SARS-CoV-2 infection are critically needed to inform national and global policy on Covid-19 vaccine use. In Israel, healthcare personnel (HCP) were initially prioritized for Covid-19 vaccination, creating an ideal setting to evaluate early real-world VE in a closely monitored population. METHODS: We conducted a prospective study among HCP in 6 hospitals to estimate the effectiveness of the BNT162b2 mRNA Covid-19 vaccine in preventing SARS-CoV-2 infection. Participants filled out weekly symptom questionnaires, provided weekly nasal specimens, and three serology samples - at enrollment, 30 days and 90 days. We estimated VE against PCR-confirmed SARS-CoV-2 infection using the Cox Proportional Hazards model and against a combined PCR/serology endpoint using Fisher's exact test. RESULTS: Of the 1567 HCP enrolled between December 27, 2020 and February 15, 2021, 1250 previously uninfected participants were included in the primary analysis; 998 (79.8%) were vaccinated with their first dose prior to or at enrollment, all with Pfizer BNT162b2 mRNA vaccine. There were four PCR-positive events among vaccinated participants, and nine among unvaccinated participants. Adjusted two-dose VE against any PCR-confirmed infection was 94.5% (95% CI: 82.6%-98.2%); adjusted two-dose VE against a combined endpoint of PCR and seroconversion for a 60-day follow-up period was 94.5% (95% CI: 63.0%-99.0%). Five PCR-positive samples from study participants were sequenced; all were alpha variant. CONCLUSIONS: Our prospective VE study of HCP in Israel with rigorous weekly surveillance found very high VE for two doses of Pfizer BNT162b2 mRNA vaccine against SARS-CoV-2 infection in recently vaccinated HCP during a period of predominant alpha variant circulation. FUNDING: Clalit Health Services.
Subject(s)
COVID-19 Vaccines , COVID-19 , BNT162 Vaccine , Delivery of Health Care , Hospitals , Humans , Prospective Studies , SARS-CoV-2 , Vaccine Efficacy , Vaccines, Synthetic , mRNA VaccinesABSTRACT
Reasons why care does not conform to single-disease guideline recommendations for multimorbid patients have not been systematically measured in practice. Using a mixed methods approach, we identified and quantified types of reasons why care deviates from nine sets of disease guideline recommendations for multimorbid patients. Utilizing a focus group concept mapping technique, we built on a categorization of reasons explaining guideline deviation, and surveyed treating nurses about these reasons for patients' specific care processes. Directed content analysis was conducted to classify the responses into reasons categories. Of 4,386 guideline-recommended care processes evaluated, 920 were not guideline-concordant (944 reasons). Three broad categories of reasons and 18 specific reasons were identified: Biomedical-related occurred 35.2% of the time, patient personal-related (30.4%), context-related (18.4%), and unknown (16.0%). Patient- and context-related factors are prevalent drivers for guideline deviation in multimorbidity, demonstrating that patient-centered aspects are as much a part of care decisions as biomedical aspects.