COVID-19 Updates — Breaking Down the Delta Variant and Immunity from Previous Infection vs COVID-19 Vaccines

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    Delta is the latest COVID-19 variant to capture global attention, as new research emerges about its transmission rate and responsiveness to vaccines and natural immunity. Professor Roger Seheult, MD, breaks down what we know about the Delta variant and how it compares to other SARS-CoV-2 mutations. 


    Delta Variant and Vaccines

    In our 130th COVID-19 update, Dr. Seheult summarizes information on viral variants and mutations in general, then focuses on the Delta variant, also known as variant B.1.617.2. Initial data on the Delta variant, first discovered in India, shows that it is more contagious than the original SARS-CoV-2 virus, and this pre-print study from the Imperial College London showed an increased prevalence among younger people, aged 5-49. While the UK variant (B.1.1.7) has recently been the most common variant in places like the UK and United States, the increasing number of Delta variant cases are quickly outpacing those of B.1.1.7. 

    Next, Dr. Seheult focuses on data surrounding the efficacy of vaccines — specifically, Pfizer-BioNTech, Moderna, Oxford-AstraZeneca, and Johnson & Johnson — against the Delta variant, in terms of infection and hospitalization. He reviews various studies from the UK, Canada, Israel, and Scotland. Watch the full video here for details on each vaccine and how they fared against the Delta variant. 


    Previous COVID-19 Infection & Vaccines Versus the Delta Variant

    In our 131st COVID-19 update, Dr. Seheult discusses the question: does natural immunity offer sufficient protection against the Delta variant? Various studies, including this paper from the Cleveland Clinic and this study from Qatar, suggest that natural immunity from a previous COVID-19 infection offers some immunity from COVID-19, but, notably, this data was collected before the Delta variant became an issue. 

    Another pre-print study, published in Nature, however, highlighted the ineffectiveness of monoclonal antibody treatments, such as Bamlanivimab, against the Delta variant. In addition, this study showed that unsurprisingly, previously uninfected (with no natural immunity), unvaccinated people are at the highest risk of serious infection from the Delta variant. For doctors and other frontline healthcare workers treating COVID-19 patients, Dr. Seheult recommends this MedCram course on using lung ultrasounds for COVID-19.


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