seacoaster wrote: ↑Mon Nov 29, 2021 10:14 am
From the Post this AM:
https://www.washingtonpost.com/health/2 ... RXBVCRLCTI
"What do we know about the new variant?
Omicron’s genetic profile is unique from other circulating variants, meaning it represents a new lineage of the virus.
It is distinct from other variants in another critical way: There’s a greater number of mutations. Tulio de Oliveira, director of the Center for Epidemic Response and Innovation in South Africa, said there are more than 30 mutations in the spike protein, the part of the virus that binds to human cells, allowing it to gain entry.
Scientists are worried those mutations could make omicron more transmissible and potentially equipped to defy immune defenses, making vaccines less effective. The WHO said Friday that preliminary evidence suggests an “increased risk of reinfection” compared with other variants.
“The one good news, if there’s any good news, is that this variant, the B.1.1.529, can be detected by one particular PCR assay,” de Oliveira said at a news conference, meaning diagnostic labs can quickly identify the new variant.
Jesse Bloom, a virologist at the Fred Hutchinson Cancer Research Center, who has conducted mutational scanning experiments for the variant, noted that three mutations could make the virus a more elusive target for antibodies produced through vaccines or prior infection.
“What that’s going to mean for how likely people are to get infected, even if they’ve been vaccinated, it’s too early to say,” Bloom said, noting that more traditional experiments should provide more data. “But having a drop in the antibody neutralization is never a good thing.”
Linda Bauld, a professor of public health at the University of Edinburgh, said there were “genuine” causes for concern given that “it does look like a more transmissible variant.” But she added: “I think it’s premature to panic. … There’s just a lot we don’t know at the moment.”
What’s being done to halt the spread of omicron?
Within days of the discovery of the variant, several countries began imposing restrictions on flights to and from South Africa and its neighbors.
Israel closed its borders to “foreigners from all countries.” Australia, Britain, the United States, Japan, Thailand are among nations curbing travel from southern Africa or imposing new quarantine rules for those arriving from the region. The United Kingdom said Saturday that it would require all international travelers to take a PCR test within two days of arrival and quarantine until their test returns a negative result.
The U.S. restrictions will apply to travelers from South Africa, Botswana, Zimbabwe, Namibia, Lesotho, Eswatini, Mozambique and Malawi. They do not apply to American citizens and lawful permanent residents. President Biden, in a statement, said the move is “a precautionary measure.” He urged Americans to get vaccinated and get booster shots.
Officials in South Africa expressed concern about the travel bans, while some experts cast doubt on the efficacy of the restrictions, noting that they may be too late. The nation’s health minister, Joe Phaahla, characterized them as a “draconian reaction.”
“It really doesn’t look scientific in any way,” he said. “That kind of reaction is quite a knee-jerk and panicked and almost wants to put a blame on other countries rather than work together.”
Before the novel coronavirus spread through the world, a study published in February 2020 in the Journal of Emergency Management found that a travel ban could delay the arrival of an infectious disease in a country by days or weeks. However, little evidence suggested it eliminated the risk of the virus jumping borders in the long term.
Amesh Adalja, an infectious-disease physician and professor at Johns Hopkins University, said the measure would do little or nothing to curb the spread of a variant that may have been “spreading for probably several days or weeks before it was noticed.”
Faheem Younus, an infectious-disease specialist at the University of Maryland, said that by the time travel bans are imposed, “the new variant has already traveled out of the country.” He noted that the O.R. Tambo International Airport near Johannesburg serves more than 1 million travelers a month.
“These bans also come at a cost and will disincentive other countries in the future,” he said. “‘Why alert the world promptly if that means your people will be punished and your economy crushed?’ they might wonder.”