Rapid tests may not detect omicron early in infection
Rapid antigen tests for COVID-19 may not reliably detect the omicron variant during the first few days of infection, even when a person is shedding the virus in high enough quantities to be contagious, preliminary evidence hints.
For the new study, posted Wednesday (Jan. 5) to the preprint database medRxiv, researchers looked at 30 people from five different workplaces in New York and California, all of whom tested positive for SARS-CoV-2 in December 2021. Due to their workplace policies, each person was undergoing both daily rapid tests and daily PCR tests, which take longer to process but can detect smaller amounts of virus. People in the study used the Abbott BinaxNOW and Quidel QuickVue rapid antigen tests, which are both approved for use by the Food and Drug Administration (FDA).
Of the participants, all but one were likely infected with the omicron variant, based on how a genetic quirk of the variant shows up on PCR tests, the team noted in their report.
On the day of each person's first positive PCR test, and on the day after, their rapid tests all came back negative, STAT News reported. It wasn't until nearly two days after the positive PCR that any of the rapid tests came back positive. Across all the subjects, "the median time from first positive PCR to first detectable antigen positive was three days," the researchers wrote in their report.
That's despite the fact that, in 28 of the 30 cases, the amount of virus detected by PCR was high enough to infect other people on Day 1, STAT News reported. Through contact tracing, the team confirmed that in four of those cases, infected people passed on the virus to others while still testing negative on rapid tests.
"It's absolutely likely there were many more than four transmissions," lead author Blythe Adamson, the principal epidemiologist at Infectious Economics in New York and an employee of Flatiron Health, an affiliate of Roche, told STAT News. "We named four because there were four that were confirmed through contact tracing and epidemiology investigation. There were likely many more."
While the findings are worrisome, other early data and anecdotal reports hint there may be a way to make these tests more sensitive earlier on in infection, by swabbing the throat in addition to the nose, The New York Times reported. This idea still needs to be verified with further research. In the meantime, the study highlights the importance of isolating if you have any COVID-19 symptoms — even if you have a negative result on a rapid test.
A negative rapid test result is "not a ticket that allows you to go back to normal or to drop any other measures," Isabella Eckerle, a clinical virologist at the University of Geneva in Switzerland, told the Times. And in particular, people should exercise caution if they've tested negative on a rapid test but have symptoms consistent with COVID-19, or believe they've been exposed to the virus.
The new study has not yet been peer-reviewed, but its results do align with a recent update from the FDA. Based on the agency's own lab studies, "Early data suggests that antigen tests do detect the omicron variant but may have reduced sensitivity," the update reads. That said, reduced sensitivity in the lab doesn't always translate to reduced sensitivity in real-world applications, Bruce Tromberg, director of the National Institute of Biomedical Imaging and Bioengineering, told The New York Times.
The new preprint hints that, indeed, this reduced sensitivity noted by the FDA may also translate to real-world test results, thus creating a lag between positive PCR results and positive rapid results. This does not mean rapid tests are useless — they can still detect the omicron variant, they just take longer to do so than PCR.
"Due to immediate turnaround time, frequent rapid antigen testing does slow transmission — and with a highly infectious variant frequent testing is needed, which is not realistic with PCR," Abbott spokesman John Koval told the Times. Plus, PCR tests may not be as readily available as at-home rapid tests. So rapid tests still have utility; people should just be wary of false-negative results, test themselves at least twice over two consecutive days following an exposure, and keep track of potential COVID-19 symptoms regardless of their test results, the Times reported.
The big question now is, why are the rapid tests less sensitive to the omicron variant? Rapid antigen tests detect proteins on the coronavirus's surface, and as the virus mutates, these proteins can become less recognizable to the test. Once these problem mutations are identified, "adjustments to existing tests can be undertaken by each developer with support from the FDA, if appropriate," FDA spokeswoman Stephanie Caccomo told the Times.
That said, the rapid tests may have a second Achilles heel: The FDA-approved rapid tests are only approved for use in the nose, not the throat or mouth. Anecdotal reports and preliminary studies have hinted that omicron may replicate faster in the mouth and throat than it does in the nose, the Times reported. And the authors of the medRxiv paper found similar results in an analysis of five people in their study who took both nose swab- and saliva-based PCR tests. They found that, in these individuals, the amount of virus in their saliva peaked one to two days before that in their noses.
"The major unknown is what it has been for weeks now: Are the [rapid antigen tests] inherently less able to detect omicron, or is there less omicron to detect on nasal swabs?" John Moore, a professor of microbiology and immunology at Weill Cornell Medical College, told STAT News. For now, the answer to that question remains unclear.
https://www.livescience.com/rapid-test-accuracy-omicron-coronavirus-infections
*******************************************************Vaccines Not Durable, Omicron Might Turn COVID-19 Endemic
Bill Gates, in a Twitter discussion Tuesday, said that the current COVID-19 vaccines were missing two key factors, and claimed that Omicron might bring about a wave of immunity in communities it passes through.
Microsoft co-founder and one of the world’s richest men, Gates has invested in vaccine research through his foundation and given prominent talks regarding the pandemic. Recently, he chatted regarding the current situation of COVID-19, vaccines, and related issues with Devi Sridhar, a professor at the University of Edinburgh where she holds a Personal Chair in Global Public Health.
When asked about a breakthrough that could result in the biggest difference in ending the pandemic, he talked about the efficacy of vaccines.
“The vaccines we have prevent severe disease and death very well but they are missing two key things. First they still allow infections (‘breakthrough’) and the duration appears to be limited. We need vaccines that prevent re-infection and have many years of duration,” Gates said.
The effectiveness of vaccines has been questioned, especially with regards to the Omicron variant. The high number of mutations on the variant’s spike protein increases “the possibility of immune escape,” according to Moderna President Stephen Hoge. Hoge added that the “dent in our vaccine’s efficacy” applies to all manufacturers.
Omicron has spread rapidly across the world, with 98.3 percent of infections in the United States now attributed to it. Although highly transmissible, international studies have shown that the strain poses milder symptoms in infected people.
Recently, a notable international health charity called for treating COVID-19 “like the common cold.” Dr. Mike Tildesley, a University of Warwick professor, has forecast COVID-19 evolving to become less severe and endemic. He said the Omicron variant is the beginning of that process. Gates has seconded this perspective.
“Once Omicron goes through a country then the rest of the year should see far fewer cases so COVID can be treated more like seasonal flu,” he said, while recommending yearly COVID-19 shots that would be needed for some time.
Gates talked about a lot of “misinformation” regarding him spreading on social media. “People like you and I and Tony Fauci have been subject to a lot of misinformation. I didn’t expect that. Some of it like me putting chips in arms doesn’t make sense to me—why would I want to do that?”
The billionaire then discussed the availability of vaccines around the world. Although there was demand, logistical issues and inefficient health systems prevented the adequate supply of vaccines in developing nations.
Regarding the Chinese authorities’ theory that the coronavirus emerged from a bat in a wet market located in Wuhan, Gates defended this argument. This is despite mounting evidence suggesting that the novel coronavirus, otherwise known as the CCP (Chinese Communist Party) virus escaped from a government lab in the Chinese city.
When Sridhar asked about the origin of the pandemic, Gates replied, “The data is pretty strong that it came from another species which is true for most pandemics. People will continue to speculate on this and we should make sure labs are careful. There will be future outbreaks coming from other species so we need to invest in being ready.”
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Virginia’s New GOP Governor Ends Vaccine Mandate for State Employees, Mask Mandates in Schools
Glenn Youngkin, the first Republican to win the state of Virginia since 2009, was sworn in as the state’s 74th governor on Jan. 15.
Within hours of his inauguration, he signed 11 executive actions including lifting the mask mandate in Virginia schools and “ending divisive concepts, including critical race theory, in public education.”
He also signed an executive directive rescinding the vaccine mandate for all state employees.
The 55-year-old former business executive, in his inauguration speech at Richmond, emphasized a “common path forward” with “our deep and abiding respect for individual freedom.” Youngkin vowed to strengthen and renew the “spirit of Virginia” associated with the history of the state as the home of American democracy. He credited Virginians with the spirit of tenacity, grit, and resilience.
Youngkin said he was “ready to lead and serve, starting on day one,” and it would start in the classroom to get Virginia’s children “career and college ready.” The crowd of an estimated size of 6,000 burst into a loud cheer upon hearing from Youngkin that he would “remove politics from the classroom.”
“Virginia is open for business,” Youngkin promised to create 400,000 new jobs and 10,000 new startups in the four years of his administration by reducing regulations and increasing job-related training.
According to him, residents of the commonwealth will see the “largest tax rebate in Virginia’s history.” In addition, he promised to “fully fund” and “return respect to” law enforcement.
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Also see my other blogs. Main ones below:
http://edwatch.blogspot.com (EDUCATION WATCH)
http://antigreen.blogspot.com (GREENIE WATCH)
http://pcwatch.blogspot.com (POLITICAL CORRECTNESS WATCH)
http://australian-politics.blogspot.com/ (AUSTRALIAN POLITICS)
http://snorphty.blogspot.com/ (TONGUE-TIED)
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