Studies: Omicron has higher ‘asymptomatic carriage’

Health workers prepare their work station at a free testing center for COVID-19 in Buenos Aires on Jan 10, 2022. (ALEJANDRO PAGNI / AFP)

MEXICO CITY / SANTIAGO / HAVANA / LUSAKA / LONDON / MADRID / KAYUNGA / WARSAW / JOHANNESBURG – Preliminary findings from two South African clinical trials suggest the Omicron coronavirus variant has a much higher rate of "asymptomatic carriage" than earlier variants, which could explain why it has spread so rapidly across the globe.

The studies – one of which was carried out when Omicron infections were surging in South Africa last month and another which resampled participants around the same time – found a far greater number of people tested positive for the coronavirus but were not showing symptoms compared to previous trials.

The studies – one of which was carried out when Omicron infections were surging in South Africa last month and another which resampled participants around the same time – found a far greater number of people tested positive for the coronavirus but were not showing symptoms compared to previous trials

In the Ubuntu study evaluating the efficacy of Moderna's COVID-19 vaccine in people living with HIV, 31 percent of 230 participants undergoing screening tested positive, with all 56 samples available for sequencing analysis verified to be Omicron.

"This is in stark contrast to the positivity rate pre-Omicron, which ranged from less than 1 percent to 2.4 percent," the researchers said in a statement.

In a subgroup of the Sisonke trial evaluating the efficacy of Johnson & Johnson's COVID-19 vaccine, the mean asymptomatic carriage rate rose to 16 percent during the Omicron period from 2.6 percent during the Beta and Delta outbreaks.

"The Sisonke study included 577 subjects previously vaccinated, … with results suggesting a high carriage rate even in those known to be vaccinated," the researchers said.

They added that the "higher asymptomatic carriage rate is likely a major factor in the rapid and widespread dissemination of the variant, even among populations with high prior rates of coronavirus infection".

South Africa experienced a surge in COVID-19 infections from late November, around the time its scientists alerted the world to Omicron. But new cases have since fallen back and early indications are that the wave has been marked by less serious disease than earlier ones.

ALSO READ: With peak yet to come, Europe's healthcare creaks under Omicron

Bulgaria's new Prime Minister and leader of We Continue the Change party Kiril Petkov (center) speaks before being sworn in at the Bulgarian Parliament building in Sofia on Dec 13, 2021.


Bulgaria's prime minister, president and several senior ministers have gone into precautionary self-isolation after a participant at a security meeting they attended tested positive for the coronavirus, a health official said on Tuesday.

Chief health inspector Angel Kunchev said all of the participants of the consultative National Security Council on Monday were in good health but they would stay in self-isolation after Parliament Speaker Nikola Minchev tested positive for the virus.

Canadian Prime Minister Justin Trudeau speaks during a press conference on the COVID-19 situation, Jan 5, 2022, in Ottawa, Canada. (DAVE CHAN / AFP)


Canadian Prime Minister Justin Trudeau said on Monday the government has secured enough COVID-19 vaccine doses for all eligible Canadians to receive a booster as well as a fourth dose, according a statement from Trudeau's office.

Trudeau made the comments in a call with Canada's provincial and territorial premiers, as the country grapples with rising infection and hospitalization rates due to the highly infectious Omicron variant.

Trudeau said the government also plans to deliver 140 million rapid COVID tests to provinces and territories in January, according to the statement.


Chile on Monday said it had detected over 1,000 cases of the Omicron variant of COVID-19, reporting a total of 1,046 cases, including cases of community transmission.

At a press conference, Undersecretary of Public Health Maria Teresa Valenzuela said the recent rise in the number of infections could be traced to the Omicron variant.

Of the 1,046 infections registered, 944 appeared to have caught the variant while traveling, 18 from close contacts, and 84 through community transmission, said Valenzuela.


Cuba on Monday registered 2,519 new daily cases of COVID-19 and one related death in 24 hours, pushing the national tally to 979,929 cases and 8,329 deaths, the Public Health Ministry said.

It was the third day in a row that new daily cases topped 2,000, the ministry said, adding there were 9,993 active COVID-19 cases in Cuba, including 35 patients in intensive care units.

A man checks his EU Digital COVID-19 certificate on his mobilephone at El Prat airport in Barcelona on July 1, 2021.


European governments are relaxing COVID-19 rules to keep hospitals, schools and emergency services going as the much more contagious but less lethal Omicron variant changes their approach to the pandemic.

Even though a record surge in infections has yet to peak in Europe, Spanish Prime Minister Pedro Sanchez said the time was right to start evaluating the disease's evolution "with different parameters".

The mass return of children to school after the Christmas holidays is evidence that few wish to see a return to the online-only learning that marked some of the early waves of infection.

Even as France registered a record seven-day average of almost 270,000 cases a day, it eased testing protocols for schoolchildren, saying too many classes were closed.

In France, the number of people in hospital with COVID-19 rose by 767, the biggest increase since last April 2021, although the total number, at 22,749 was still around two-thirds of the peak, set in November 2020.

Britain began using military personnel to support healthcare and alerted its biggest private health company that it might be required to deliver treatments including cancer surgery. 

Spain was bringing back retired medics. In Italy, the challenge of nearly 13,000 health workers being absent with positive COVID-19 tests was compounded by suspensions for non-vaccination.

Britain, Switzerland, Spain and Belgium have all slashed quarantine periods and eased conditions for staff to return to work.

The Czech Republic followed suit on Monday, saying critical staff including teachers, social workers and doctors could keep working even after testing positive.

This handout picture released by the Mexican Presidency, shows Mexican President Andres Manuel Lopez Obrador during a press conference at the Palacio Nacional in Mexico City on Jan 10, 2022. (MEXICAN PRESIDENCY / AFP)


Mexican President Andres Manuel Lopez Obrador on Monday announced he had contracted COVID-19 for a second time, saying he had a mild case and that he would keep working in isolation until he had recovered.

The 68-year-old Lopez Obrador, who also tested positive for COVID-19 in January last year, sounded hoarse during his morning news conference on Monday, prompting him to say he would take a test later in the day.

"Although the symptoms are mild, I will remain in isolation and will only do office work and communicate virtually," until recovering, Lopez Obrador said in a tweet.

For now, Interior Minister Adan Augusto Lopez will replace the president during his daily morning press conferences and other official acts, Lopez Obrador added.

In this file photo taken on Oct 12, 2021, Pfizer CEO Albert Bourla delivers a speech during the inauguration ceremony of the company's new center for Digital Innovation and Business Operations and Services in Thessaloniki. (SAKIS MITROLIDIS / AFP)


Pfizer Inc Chief Executive Albert Bourla on Monday said a redesigned COVID-19 vaccine that specifically targets the Omicron coronavirus variant is likely needed and his company could have one ready to launch by March.

Pfizer Inc Chief Executive Albert Bourla said Pfizer could be ready to file for US regulatory approval for a redesigned vaccine and launch it as soon as March

Bourla said Pfizer and partner BioNTech SE are working on both an Omicron-targeted vaccine version as well as a shot that would include both the previous vaccine as well as one targeted at the fast-spreading variant.

"I think it is the most likely scenario," Bourla said, speaking at JP Morgan's annual healthcare conference, which is being held virtually this year. "We're working on higher doses. We're working different schedules. We're doing a lot of things right now, as we speak."

Bourla said Pfizer could be ready to file for US regulatory approval for a redesigned vaccine and launch it as soon as March. Bourla said Pfizer has built up so much manufacturing capacity for the vaccine that it will not be a problem to switch immediately.

COVID-19 vaccines eventually could be an annual shot for most people, Bourla said, and some high-risk groups might be eligible to receive the shots more often than that.

Moderna Inc CEO Stephane Bancel said last week that people could need another shot this fall, as the efficacy of boosters is likely to decline over the next few months.


Poland's total number of coronavirus-related deaths surpassed 100,000 on Tuesday, the health minister said, as the country grapples with a fourth wave of the pandemic.

The number of deaths per one million inhabitants was last week among the highest in the world, according to the Our World in Data project at the University of Oxford, at more than 57 compared to around 34 in the United States and 38 in Russia.

"Today we can say it is another sad day, but especially so because we have passed the level of 100,000 COVID deaths," Adam Niedzielski told private broadcaster TVN 24.

Poland has been grappling with a consistently high number of daily COVID-19 cases. Although it has not reported a spike in cases caused by the Omicron variant of the virus, it imposed fresh restrictions in December to curb the spread of infection.

As of Monday, the health ministry estimates that the Omicron variant accounted for between 7 and 8 percent of new daily cases.

In this file photo taken on Aug 16, 2021,
medics transfer a patient on a stretcher from an ambulance outside of Emergency at Coral Gables Hospital where Coronavirus patients are treated in Coral Gables near Miami. (CHANDAN KHANNA / AFP)


The United States reported 1.35 million new coronavirus infections on Monday, according to a Reuters tally, the highest daily total for any country in the world as the spread of the highly contagious Omicron variant showed no signs of slowing.

The previous record was 1.03 million cases on Jan 3. A large number of cases are reported each Monday due to many states not reporting over the weekend. The seven-day average for new cases has tripled in two weeks to over 700,000 new infections a day.

There were more than 136,604 people hospitalized with COVID-19, surpassing the record of 132,051 set in January last year.The record in new cases came the same day as the nation saw the number of hospitalized COVID-19 patients also hit an all-time high, having doubled in three weeks, according to a Reuters tally.

While the Omicron variant is potentially less severe, health officials have warned that the sheer number of infections could strain hospital systems, some of which have already suspended elective procedures as they struggle to handle the increase in patients and staff shortages.

The surge in cases has disrupted schools, which are struggling with absences of staff, teachers and bus drivers.

Meanwhile, the true number of deaths from the COVID-19 pandemic in the United States is probably being undercounted – many deaths are not counted because they happen months after infection, according to an insurance company CEO.

"The deaths that are being reported as covid deaths greatly understate the actual death losses among working-age people from the pandemic," The Guardian quoted Scott Davison, CEO of OneAmerica, as saying.

Deaths from COVID-19 aftermath have been difficult to track, since the virus may no longer be present at the time of death but had weakened organs or created fatal new ailments, the newspaper said.

Meanwhile, an expert predicted that some 5 million Americans could skip work this week with COVID-19, putting strain on business and transport, British newspaper Daily Mail has reported.

Most experts believed the infections will continue to increase in the United States for the next few weeks before the Omicron surge peaks in late January, with Dr Anthony Fauci saying that the country will likely record more than 1 million cases daily on a regular basis.


Spain passed the benchmark of 90,000 COVID-19 deaths on Monday, according to the latest data published by the country's Ministry of Health.

The ministry confirmed 202 deaths over the period from 2:00 pm local time (1300 GMT) on Friday and the same time on Monday, raising the total number of deaths to 90,136 in the country since the start of the pandemic.

Over the 72-hour period, 292,394 new cases were reported, lifting the total number of infections to 7,457,300, while the 14-day incidence of the virus climbed 267.2 points to 2,989.47 cases per 100,000 inhabitants.


Health authorities in Zambia on Monday said the country was facing a challenge of availability of diagnostic tests kits for COVID-19 following a surge in cases driven by the Omicron variant.

"This is due to supply challenges due to the pandemic itself where we see increased global demand for the test and other supplies required for response," the Minister of Health Sylvia Masebo told reporters during a COVID-19 update press briefing.

She said the situation has further been worsened by the country's limited resource envelope, adding that widespread community transmission occurring in nearly all districts has led to an increased demand for testing.