COVID: The latest science on the fast-spreading omicron variant

Five months after a second dose of the Pfizer vaccine, the blood of vaccinated people could not neutralize omicron.But two doses are still protective against severe illness with omicron.The two-dose Pfizer-BioNTech vaccination provides 70% protection against severe complications of COVID-19 requiring hospitalization, according to the South African study. Protection was uniform across a wide range of chronic illnesses, including diabetes and hypertension.That’s happening because, even when antibodies fade, there’s help from the part of the immune system that produces virus-killing T cells, said virologist Penny Moore of the University of the Witwatersrand in Johannesburg, at a Tuesday meeting of The New York Academy of Sciences.“This other arm of the immune system is generally what does a lot of the heavy lifting when it comes to preventing people from becoming severely ill,” she said.Omicron is more easily transmitted.Omicron is almost four times more infectious than the original strain and twice as infectious as delta, according to lab work with a synthesized omicron variant at Massachusetts’ Ragon Institute.Ever since the virus jumped from animals to humans, “it’s been learning how to infect people better,” said Dr. Drew Weissman of the University of Pennsylvania, whose work enabled the creation of mRNA vaccines.Omicron infections seem less severe than infections with delta and other variantsSouth African hospitals reported that the risk of admissions was 29% lower for people infected with omicron, compared to earlier waves.