Link to free download of my 2 textbooks http://159.69.48.3/ Physiology book in hard copy https://www.ebay.co.uk/itm/154770452796?mkevt=1&mkcid=16&mkrid=710-127635-2958-0 Pathophysiology book in hard copy https://www.ebay.co.uk/itm/154770451780?mkevt=1&mkcid=16&mkrid=710-127635-2958-0 US variants data https://covid.cdc.gov/covid-data-tracker/#variant-proportions https://www.nytimes.com/interactive/2022/01/22/science/charting-omicron-infection.html US omicron history November 29 Index patient, 48 year old unvaccinated man, Nigeria Nebraska, 6 people diagnosed by PCR and genomic sequencing Onset was 73 hours (range = 33–75 hours) Incubation period https://www.cdc.gov/mmwr/volumes/70/wr/mm705152e3.htm Original version, five days The Delta variant, four days Omicron, 2 to 3 days Viral Load https://www.nejm.org/doi/full/10.1056/NEJMc2102507 Alpha and Delta variants Peak viral load 3 days after infection Clear the virus about six days after that Infectious viral load in unvaccinated and vaccinated patients infected with SARS-CoV-2 WT, Delta and Omicron https://www.medrxiv.org/content/10.1101/2022.01.10.22269010v2.full.pdf Omicron and Delta produced similar levels of infectious virus Infections a day shorter with omicron compared to delta Omicron infects upper airways as opposed to lungs Omicron antibodies neutralise delta virus Offshoot of Omicron variant, England https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/1046614/12-january-2022-risk-assessment-SARS-Omicron_VOC-21NOV-01_B.1.1.529.pdf https://www.theguardian.com/world/live/2022/jan/22/coronavirus-live-japan-and-taiwan-report-omicron-surges-ireland-lifts-restrictions BA.2 may be even more contagious than original omicron UK Health Security Agency Designating BA.2 a variant under investigation increasing numbers of BA.2 sequences identified both domestically and internationally May have an increased growth rate over BA.1 Vaccine effectiveness with omicron https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/1048395/technical-briefing-34-14-january-2022.pdf After a 2-dose primary course of vaccination Vaccine protection against mild disease has largely disappeared by 20 weeks after vaccination After a booster dose Protection initially increases to around 65 to 70% but drops to 45 to 50% from 10+ weeks Therefore It is therefore likely that current vaccines offer limited long-term protection against infection or transmission. Protection against severe disease Vaccine effectiveness against hospitalisation is estimated at 92% and remains high at 83% 10+ weeks after the booster dose John’s booster 20th November So my protection against hospitalisation goes down from 92% to 83% by soon