The latest on the coronavirus pandemic and vaccines

Rapid antigen tests for Covid-19 are less accurate than RT-PCR tests for Covid-19, the Centers for Disease Control and Prevention said Thursday – often even less accurate than advertised. 

The fast tests may be missing many cases of infection, the CDC-led team said. And they are also often telling people they are infected when, in fact, they are not. 

Antigen tests are generally cheaper than polymerase chain reaction or PCR tests, and can return results in as little as 15 minutes. Multiple tests in both categories have gotten Emergency Use Authorization from the Food and Drug Administration, but a study published in the CDC’s Morbidity and Mortality Weekly Report found that antigen tests were not only less accurate than PCR tests, but less accurate than what was reported when the FDA gave emergency authorization.

“Among people reporting COVID-19 symptoms at the time the samples were collected, the Sofia antigen test was less accurate than reported in the FDA Emergency Use Authorization,” the CDC-led team wrote. Antigen testing in this study had a sensitivity rate of 80%, compared to a previously reported 97%.

The researchers investigated the tests at two Wisconsin universities by administering Quidel’s Sofia antigen test and a PCR test to both symptomatic and asymptomatic participants. Antigen tests quickly seek out evidence of the virus, which PCR tests take longer but work by amplifying genetic material from the virus.

“The Sofia rapid antigen test was less accurate than RT-PCR for detecting SARS-CoV-2 infections in students and faculty tested at two universities in Wisconsin,” the researchers wrote. “The antigen test accuracy was lowest among study participants not showing symptoms (asymptomatic),” they added.

Investigators said that antigen tests may still be valuable in tracking infection because they are cheaper and quicker, and may be more accessible than PCR tests. But results from antigen tests should be paired with more accurate testing.

“To account for reduced test accuracy of antigen tests, CDC recommends considering confirmatory testing with an FDA-authorized molecular test, such as RT-PCR, following negative antigen test results in people who have COVID-19 symptoms, and following positive antigen test results in asymptomatic people,” said researchers.

The city and county of San Francisco will be extending its stay-at-home order and mandatory 10-day quarantine requirement amid the ongoing coronavirus surge, officials announced in a news release on Thursday.

While the state’s regional stay-at-home order for the Bay Area is set to expire on Jan. 8, San Francisco announced that it does not expect the region to meet the state’s threshold of an intensive care unit bed capacity above 15%.

The current intensive care unit bed capacity for the Bay Area is 7.5%, according to data from the California Department of Public Health. 

Anyone visiting, moving to, or returning to San Francisco from anywhere outside the Bay Area is required to quarantine for 10 days. The health order also strongly discourages any non-essential travel within the 10-county Bay Area region. 

According to the release, the health orders appear to have slowed the infections and more than 400 deaths may have been prevented.  

More details: The extension of both health orders will continue until the Bay Area Region is no longer subject to the state’s regional stay at home order. Both health orders, implemented on Dec. 17, were set to expire on Jan. 4.

San Francisco is one of the most densely populated counties in the nation.

Speaking during his New Year’s address, UK Prime Minister Boris Johnson expressed confidence about 2021, noting that while there is still work to be done to overcome the pandemic, new coronavirus vaccines have brought hope and certainty to the country. 

“We can see that illuminated sign that marks the end of the journey, and even more important, we can see with growing clarity how we are going to get there,” he added. 

The prime minister acknowledged that the last year has been characterized by “grimness” and expressed regret that families across the country “lost too many loved ones before their time,” but stressed that the government’s mass vaccination program is “changing the odds in favor of humanity and against Covid.”

“I believe 2021 is, above all, the year when we will eventually do those everyday things that now seem lost in the past, bathed in a rosy glow of nostalgia – going to the pub, concerts, theaters, restaurants, or simply holding hands with our loved ones in the normal way,” Johnson said. 

The prime minister’s message comes as England prepares for tougher coronavirus regulations to be come into force across the country, with the number of confirmed coronavirus cases reaching record highs and pressure on the National Health Service  mounting.

Republican Sen. Lindsey Graham, a top ally of President Trump, said Thursday morning that he would like a stand-alone vote on $2,000 stimulus checks in the new session of Congress, which begins this Sunday.

Graham also called for stand-alone votes on the two other issues Trump has been pushing, a full repeal of online liability protections and an investigation into voter fraud. 

“I am urging Sen. McConnell to give us standalone votes in the new Congress, after Jan. 3rd on all three measures,” the South Carolina senator said.

Graham is expecting to be the top Republican on the Budget Committee next year, CNN’s Ted Barrett notes.

Some background: Senate Majority Leader Mitch McConnell on Thursday blasted the House bill increasing stimulus payments to $2,000, arguing that giving $2,000 checks to high earning households who haven’t faced job loss is “socialism for rich people”

A Covid-19 outbreak has been confirmed at a Costco store in Washington state.

According to a news release from the Yakima Health District, 145 Costco employees have tested positive for Covid-19. Employees who have tested positive have completed their quarantine or isolation period, the release said.

The release said that based on the number of cases and timeline, the evidence shows that the increase in cases "mimics the type of activity that happens after some sort of superspreader event." 

"Costco will continue to provide on-going site-wide testing for their employees moving forward to monitor the outbreak," the release said.

The Yakima Health District said it has not recommended closure for any business in the area, including Costco, due to the Covid-19 infections. 

Costco has required face coverings for all members, guests and employees other than those with medical conditions since May. According to a letter from their CEO, the policy was updated in November to require face coverings for anyone in the store over the age of 2. 

"Our goal is to continue to provide a safe shopping environment for our members and guests, and to provide a safe work environment for our employees," Costco CEO Craig Jelinek said in a letter posted on the company's website. 

Earlier this month, the US Centers for Disease Control and Prevention released guidance to shorten the 14-day Covid-19 quarantine to seven to 10 days. However, in its Morbidity and Mortality Weekly Report, the CDC concludes that this move "carries a risk" to further spread the virus, particularly the risk posed by household contacts.

Interim data from a CDC-supported study of household transmission of Covid-19, showed that among 185 people who lived in households with someone who was sick with Covid-19, 109 of them ended up getting Covid-19 themselves.

Of those 109 people, 76% tested positive within seven days after the person they were living with first felt sick, and 86% tested positive within 10 days after the person they were living with first felt sick. This shows that there is a potential for transmission of the virus from household contacts released from quarantine before 14 days, according to the report.

Household contacts who tested negative for the virus and were without symptoms through day seven had an 81% chance of remaining symptom free and testing negative through day 14.

But that means one in five people still became symptomatic or received a positive Covid-19, suggesting that "reducing quarantine to less than 14 days might decrease but not eliminate the risk for spreading" the virus, the report said.

A case of the new coronavirus variant first detected in South Africa in mid-December has been identified in France, the French health ministry confirmed Thursday. 

According to a statement, a man living in the area of Haut-Rhin, near the border with Switzerland, tested positive for the new variant of coronavirus “after a stay in South Africa, and following symptoms suggestive of Covid-19 that appeared a few days after his return.”

The health ministry has confirmed that the patient “immediately isolated himself at home” after experiencing symptoms and “has now recovered and is in good health.”

French health authorities proceeded to search for people who may have come into prolonged contact with the patient, but later confirmed that “none were identified,” the health ministry added. 

Following the identification of a new variant of coronavirus in South Africa, the French government announced that laboratories would be required to send all positive coronavirus test results from residents who have recently returned from South Africa to the French National Research Center. 

“A system for the detection and surveillance of possible cases of infection or carrier of the variant has been set up,” the French health ministry added.

China has confirmed its first case of the new Covid-19 variant — first identified in England — in a returning student from the UK, the Chinese Center for Disease Control and Prevention said in a report published on Wednesday.

The patient — a 23-year-old female — returned to Shanghai from Britain on Dec. 14.

"Due to the closed-loop management upon passenger’s arrival at the airport, close contact investigation has been initiated," it added.

The discovery of the case "poses a great potential threat to the prevention and control of Covid-19 in China," the health authority said.

Senate Majority Leader Mitch McConnell on Thursday blasted the House bill increasing stimulus payments to $2,000, which President Trump has pushed alongside Democratic leaders, saying it’s not targeted enough.

McConnell argued giving $2,000 checks to high earning households who haven’t faced job loss is “socialism for rich people”… “a terrible way to help the American families that are actually struggling.”

Meanwhile, Senate Democratic leader Chuck Schumer asked for the Senate to take up the House-passed bill to increase stimulus checks to $2,000, but McConnell objected.

“I will once again ask consent that the Senate set a time for a vote on the House bill to provide $2,000 checks to the American people,” Schumer said.

Schumer argued that the Senate should pass the House bill to increase stimulus checks to $2,000, saying, “There is one way and only one way to pass $2,000 checks before the end of the year and that’s to pass the House bill … Either the Senate takes up and passes the House bill or struggling Americans will not get $2,000 checks during the worst economic crisis since the Great Depression.”

“The Republican leader has invented an excuse to prevent a clean, up or down, yes or no, vote on $2,000 checks coming to the floor,” he said, adding, that McConnell’s maneuver to combine the direct payments with other unrelated issues “is intended to kill the possibility of $2,000 checks ever becoming law.”

McConnell, on Tuesday, introduced legislation that combined three Trump priorities — expanded stimulus checks, a full repeal of online liability protections and an investigation into alleged voter fraud — each a prerequisite for Trump signing the Covid relief and spending package earlier this week. Trump himself has never specified that those three items should be tied together.

But on Wednesday, McConnell said the House bill had "no realistic path to quickly pass the Senate," and said the Democratic-led effort ran astray of what Trump actually requested.

Where things stand: There are no votes scheduled on McConnell's bill, or the House-passed legislation, and GOP aides say it's likely the 116th Congress comes to an end without any action on increasing direct payments.