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Stock market news live: Stock futures mixed as traders monitor coronavirus outbreak – Yahoo Canada Finance

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U.S. stocks kicked off the week slightly higher, shaking off earlier declines as the coronavirus death toll overtook that of the 2002-2003 SARS outbreak.

<p class="canvas-atom canvas-text Mb(1.0em) Mb(0)–sm Mt(0.8em)–sm" type="text" content="Later this week, investors will receive a myriad of corporate earnings results, January retail sales data and semi-annual congressional testimony from Federal Reserve Chair Jerome Powell.” data-reactid=”16″>Later this week, investors will receive a myriad of corporate earnings results, January retail sales data and semi-annual congressional testimony from Federal Reserve Chair Jerome Powell.

4:02 p.m. ET: Stocks close higher, S&P 500 and Nasdaq see closing highs

Here’s where the major indices were as of 4:02 p.m. ET:

  • S&P 500 (^GSPC): +0.73% or +24.42 points to 3,352.13

  • Dow (^DJI): +0.60% or +174.27 points to 29,276.78

  • Nasdaq (^IXIC): +1.13% or +107.88 points to 9,628.39

  • Crude oil (CL=F): -1.57% or -0.79 to 49.53 a barrel

  • Gold (GC=F+0.21% or +3.30 to 1,576.70 per ounce

3:49 p.m. ET: Slack stock halted

<p class="canvas-atom canvas-text Mb(1.0em) Mb(0)–sm Mt(0.8em)–sm" type="text" content="Slack (WORK) stock was halted at 3:49 p.m. ET, possibly ahead of an announcement, according to Bloomberg. The stock is up more than 15% so far on Monday.” data-reactid=”28″>Slack (WORK) stock was halted at 3:49 p.m. ET, possibly ahead of an announcement, according to Bloomberg. The stock is up more than 15% so far on Monday.

<p class="canvas-atom canvas-text Mb(1.0em) Mb(0)–sm Mt(0.8em)–sm" type="text" content="Earlier Monday, reports suggested IBM (IBM) was going to have its more than 350,000 employees use Slack’s workplace communications technology, immediately unlocking a huge new user base and corporate customer for the newly public company.” data-reactid=”29″>Earlier Monday, reports suggested IBM (IBM) was going to have its more than 350,000 employees use Slack’s workplace communications technology, immediately unlocking a huge new user base and corporate customer for the newly public company.

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<h2 class="canvas-atom canvas-text Mb(1.0em) Mb(0)–sm Mt(0.8em)–sm" type="text" content="1:55 p.m. Earnings are topping expectations, but…” data-reactid=”31″>1:55 p.m. Earnings are topping expectations, but…

An electronic screen at the Nasdaq MarketSite shows the decline in the price of Apple shares, center, at the start of the trading day Wednesday, Oct. 8, 2008 in New York. Wall Street extended its huge decline Wednesday as an emergency interest rate cut failed to alleviate investors' fears that the paralysis in the credit markets will set off a global recession. (AP Photo/Mark Lennihan)

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An electronic screen at the Nasdaq MarketSite shows the decline in the price of Apple shares, center, at the start of the trading day Wednesday, Oct. 8, 2008 in New York. Wall Street extended its huge decline Wednesday as an emergency interest rate cut failed to alleviate investors’ fears that the paralysis in the credit markets will set off a global recession. (AP Photo/Mark Lennihan)

All things considered, it’s been a banner earnings season as nearly70% of S&P 500 companies beat estimates, Refinitiv data showed — well above the long-term average.

Still, Blackrock thinks the bar is being set too high, and all but guarantees a letdown:

“Analysts currently expect U.S. earnings to grow about 9% in 2020, a hair lower than the typical range for the start of the year. Yet we see that as an ambitious goal given potential for rising wages and other cost increases to further compress corporate margins. Our analysis of U.S. corporate profit margins over the stages of the business cycle since 1965 showed that profit margins have tended to contract in late-cycle periods. High earnings expectations, combined with these late-cycle dynamics and more attractive valuations in other regions, set a high bar for sustained U.S. outperformance.”

 

Add in the upcoming U.S. general election and coronavirus, and companies need to brace for “the potential for a highly volatile and noisy nine months ahead [featuring] a wide range of potential policy outcomes,” the investment giant said:  

The bottom line: We stick to our view that global growth will edge higher in 2020 but expect the pickup to be delayed. U.S. equities could outperform on any further growth scares triggered by the coronavirus outbreak, given their quality bias and perceived resilience. But we remain neutral on U.S. equities, given elevated political uncertainties and the risk to margins. Overall, we stand by our moderate pro-risk stance, and expect an eventual growth pickup to support cyclical equity markets such as EM and Japan. Within U.S. equities we favor quality companies with above average return on equity, low leverage and strong cash flow.

<h2 class="canvas-atom canvas-text Mb(1.0em) Mb(0)–sm Mt(0.8em)–sm" type="text" content="12:20 p.m. ET: Retail shipments see ‘sharper-than-usual’ drop” data-reactid=”62″>12:20 p.m. ET: Retail shipments see ‘sharper-than-usual’ drop

The National Retail Federation, which tracks retail shipment volumes at major U.S. ports, warned on Monday that the coronavirus epidemic is adding to the typical slowness associated with Lunar New Year. That means a usual slump is “sharper-than-usual,” the organization says:

“February is historically a slow month for imports because of Lunar New Year and the lull between retailers’ holiday season and summer, but this is an unusual situation,” NRF Vice President for Supply Chain and Customs Policy Jonathan Gold said.

“Many Chinese factories have already stayed closed longer than usual, and we don’t know how soon they will reopen. U.S. retailers were already beginning to shift some sourcing to other countries because of the trade war, but if shutdowns continue, we could see an impact on supply chains.”

Accordingly, trying to forecast container volumes “has become even more challenging” and it’s far from clear when the manufacturing sector will normalize, the NRF said.

<h2 class="canvas-atom canvas-text Mb(1.0em) Mb(0)–sm Mt(0.8em)–sm" type="text" content="11:20 a.m. ET: Investors unprepared for this ‘tectonic shift’” data-reactid=”74″>11:20 a.m. ET: Investors unprepared for this ‘tectonic shift’

In this photograph taken on December 8, 2016, an automated robot works on an assembly line of Highly Electrical Appliances India Pvt. Ltd. at a company air-conditioner compressor plant at Matoda, some 20 kms. from Ahmedabad. / AFP / SAM PANTHAKY (Photo credit should read SAM PANTHAKY/AFP via Getty Images)In this photograph taken on December 8, 2016, an automated robot works on an assembly line of Highly Electrical Appliances India Pvt. Ltd. at a company air-conditioner compressor plant at Matoda, some 20 kms. from Ahmedabad. / AFP / SAM PANTHAKY (Photo credit should read SAM PANTHAKY/AFP via Getty Images)

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In this photograph taken on December 8, 2016, an automated robot works on an assembly line of Highly Electrical Appliances India Pvt. Ltd. at a company air-conditioner compressor plant at Matoda, some 20 kms. from Ahmedabad. / AFP / SAM PANTHAKY (Photo credit should read SAM PANTHAKY/AFP via Getty Images)

In a lengthy study published Monday, Bank of America put a new spin on a slowly unfolding story: Namely, that global supply chains are migrating to other countries like Southeast Asia, India and even North America.

According to a BofA study, “…much more surprising was that companies in about half of all global sectors in North America declared an intent to ‘reshore’. This was particularly true for high-tech sectors and industries for which energy is a key input. If borne out, this could represent the first reversal in a multi-decade trend.”

In all, multinational companies worth $22 trillion in market cap are being impacted, and the bank warns that investors may not be ready. So what’s behind the shift? BofA noted there are several reasons, but among them are tariffs, narrowing tax advantages, and national security. And the kicker:

“In our view, these movements are ‘tectonic’: slow moving, persistent with major changes to the business environment for global companies.

“…We don’t think investors are fully prepared for this tectonic shift. In our view, the US could be a significant beneficiary of this process, while Chinese firms are perhaps most at risk. Even more striking, our survey found almost universal intent to use automation.” 

As such, the bank recommends adding exposure in automation, industrials and banks stocks in the regions set to become beneficiaries of the shift.

<h2 class="canvas-atom canvas-text Mb(1.0em) Mb(0)–sm Mt(0.8em)–sm" type="text" content="11:00 a.m. ET: Stocks and the coronavirus outbreak” data-reactid=”103″>11:00 a.m. ET: Stocks and the coronavirus outbreak

In the last couple of sessions, Wall Street has had a delayed reaction to coronavirus fears. Yet according to DataTrek, there are several reasons why stocks haven’t priced in more aggressive losses:

  • The illness is still largely contained to Mainland China, with 99% of the worldwide cases through today. Even if you do not trust the Chinese government numbers, the count outside the country is trustworthy.

  • China is addressing the outbreak aggressively, with mass quarantines and other measures enabled by its powerful authoritarian governance structure.

  • Markets know this means 1H global economic growth will slow, but they also assume a containment of the disease during this timeframe because of the steps outlined in the prior point.

  • The virus will make for a temporary truce in the US-China trade war that will extend for at least several more months. President Trump knows there is no point in pushing on the issue while the Chinese government is focused on this crisis.

  • …A 2H 2020 re-acceleration in global growth (post the presumed containment of the virus) will serve President Trump well going into the November US general election. Markets see him as better for the US economy than current Democratic front-runner Bernie Sanders.

  • Bond markets, in true on-brand form, see the economic effects of the coronavirus as modestly deflationary (more on this in a moment). Yields have therefore declined around the world, supporting equity valuations. And since central banks are fixated on deflation, the chance they will cut rates is rising.

All told, the firm points out that the stock market is more of a leading indicator, with investors pricing in where growth/earnings will end up in 6 months time. “Investors see the real possibility of a period of global economic catch-up” in the second half — and a Trump reelection bolstering next year and beyond.

10:34 a.m. ET: Stocks push higher, shaking off coronavirus fears

After opening slightly to the downside, the S&P 500 and Dow pushed into positive territory about an hour into the regular trading session.

Here were the main moves in markets, as of 10:35 a.m. ET:

  • S&P 500 (^GSPC): +0.36% or +11.85 points to 3,339.55

  • Dow (^DJI): +0.33% or +96.18 points to 29,198.69

  • Nasdaq (^IXIC): +0.53% or +51.07 points to 9,571.58

  • Crude oil (CL=F): -0.74% or -0.37 to 49.95 a barrel

  • Gold (GC=F+0.22% or +3.40 to 1,576.80 per ounce

10:32 a.m. ET: Tesla’s stock jumps again, extending incredible run

<p class="canvas-atom canvas-text Mb(1.0em) Mb(0)–sm Mt(0.8em)–sm" type="text" content="Tesla’s (TSLA) stock rose as much as much as 9.6% on Monday to $819.99 at the highs of the morning session, as shares of the electric car-maker continued to surge.” data-reactid=”120″>Tesla’s (TSLA) stock rose as much as much as 9.6% on Monday to $819.99 at the highs of the morning session, as shares of the electric car-maker continued to surge.

<p class="canvas-atom canvas-text Mb(1.0em) Mb(0)–sm Mt(0.8em)–sm" type="text" content="The stock received an apparent boost over the weekend after Chinese officials said Tesla’s Shanghai Gigafactory would resume production Monday, Feb. 10, with the government helping it work through the spread of the coronavirus, Reuters reported.” data-reactid=”121″>The stock received an apparent boost over the weekend after Chinese officials said Tesla’s Shanghai Gigafactory would resume production Monday, Feb. 10, with the government helping it work through the spread of the coronavirus, Reuters reported.

<p class="canvas-atom canvas-text Mb(1.0em) Mb(0)–sm Mt(0.8em)–sm" type="text" content="Tesla executives had said during their earnings call with investors late last month that the company would see a 1-1.5 week delay in ramping production at the Shanghai Gigafactory amid the coronavirus.” data-reactid=”122″>Tesla executives had said during their earnings call with investors late last month that the company would see a 1-1.5 week delay in ramping production at the Shanghai Gigafactory amid the coronavirus.

Shares of Tesla were up about 80% for the year to date through Friday’s close.

10:27 a.m. ET: U.S. economic growth could take a hit in Q1 as coronavirus impact spreads

U.S. real gross domestic product growth could slow well below 1% in the first quarter as the impact of the coronavirus takes hold, according to a note from UBS economist Seth Carpenter Monday. These effects, however, will likely reverse in the second and third quarters this year, he added.

We see the net effect on the US as being small, but the quarterly swings are likely to be measurable. For the US, we see the effect coming through three channels: tourism, exports, and a temporary disruption to manufacturing because of delayed imports. For Q1, we have trimmed our real GDP estimate by 0.2 [percentage points] to a 0.4% [quarter on quarter] annual rate. We assume that the hit in the US from the coronavirus is mostly reversed over the course of Q2 and Q3. There are significant risks to this forecast. Our forecast change is conditional on China reopening production next week and based on the China team’s assessment that production disruptions will be small.

<p class="canvas-atom canvas-text Mb(1.0em) Mb(0)–sm Mt(0.8em)–sm" type="text" content="UBS’s prediction for U.S. Q1 GDP is below that of the Atlanta Fed. The regional bank’s closely watched GDPNow model estimates real GDP growth of 2.7% in the first quarter.” data-reactid=”129″>UBS’s prediction for U.S. Q1 GDP is below that of the Atlanta Fed. The regional bank’s closely watched GDPNow model estimates real GDP growth of 2.7% in the first quarter.

<h2 class="canvas-atom canvas-text Mb(1.0em) Mb(0)–sm Mt(0.8em)–sm" type="text" content="10:20 a.m. ET: Chinese hackers charged with Equifax breach” data-reactid=”131″>10:20 a.m. ET: Chinese hackers charged with Equifax breach

<p class="canvas-atom canvas-text Mb(1.0em) Mb(0)–sm Mt(0.8em)–sm" type="text" content="Four Chinese military hackers have been charged in the 2017 breach of the Equifax credit reporting agency that affected nearly 150 million American citizens, Attorney General William Barr said Monday.” data-reactid=”136″>Four Chinese military hackers have been charged in the 2017 breach of the Equifax credit reporting agency that affected nearly 150 million American citizens, Attorney General William Barr said Monday.

9:35 a.m. ET: U.S. stocks open little changed amid coronavirus outbreak

The Dow and S&P 500 opened slightly in the red Monday morning as fears over the coronavirus continued to mount. However, each index pared losses from the pre-market session.

Here were the main moves in markets, as of 9:35 a.m. ET:

  • S&P 500 (^GSPC): -0.05% or -1.6 points to 3,326.11

  • Dow (^DJI): -0.04% or -12.53 points to 29,089.98

  • Nasdaq (^IXIC): +0.05% or +7.35 points to 9,529.66

  • Crude oil (CL=F): -0.97% or -0.49 to 49.83 a barrel

  • Gold (GC=F+0.28% or +4.40 to 1,577.80 per ounce

7:47 a.m. ET: Stock futures mixed as coronavirus death toll rises

Contracts on the three major indices were mixed Monday morning, after falling for the first time in five sessions on Friday. Fears over the spread of the deadly coronavirus continued to be a focal point for global investors.

As of Sunday evening, the coronavirus had claimed the lives of 908 in mainland China, and total cases rose to 40,171, according to China’s National Health Commission. Ninety-seven people died from the disease on Sunday alone. More have now been killed by the coronavirus than during the SARS outbreak of 2002 to 2003, which killed 774 individuals.

Tedros Adhanom Ghebreyesus, director-general of the World Health Organization, noted in a Twitter post Sunday that some coronavirus cases have begun to emerge even in individuals who did not travel to China.

In the UK, where there have so far been eight confirmed coronavirus cases, the country’s health secretary called the outbreak “a serious and imminent threat to public health.” Elsewhere, more than 3,000 people have been stuck on a cruise ship in Yokohama, Japan, in a two-week quarantine, with dozens on board having tested positive for the coronavirus. Separately, home-rental services Airbnb has halted bookings of all listings in Beijing through the end of February in effort to contain the coronavirus.

Here were the main moves during the pre-market session, as of 7:47 a.m. ET:

  • S&P futures (ES=F): 3,324.75, down 0.75 points or 0.02%

  • Dow futures (YM=F): 29,025.00, down 19 points or 0.07%

  • Nasdaq futures (NQ=F): 9,413.25, up points or 0.04%

  • Crude oil (CL=F): $50.18 per barrel, down $0.14 or 0.28%

  • Gold (GC=F): $1,575.10 per ounce, up $1.70 or 0.11%

A man wearing a protective face mask walks on an overpass in Lujiazui financial district in Shanghai on February 10, 2020. - The death toll from the novel coronavirus surged past 900 in mainland China on February 10, overtaking global fatalities in the 2002-03 SARS epidemic, even as the World Health Organization said the outbreak appeared to be stabilising. (Photo by NOEL CELIS / AFP) (Photo by NOEL CELIS/AFP via Getty Images)A man wearing a protective face mask walks on an overpass in Lujiazui financial district in Shanghai on February 10, 2020. - The death toll from the novel coronavirus surged past 900 in mainland China on February 10, overtaking global fatalities in the 2002-03 SARS epidemic, even as the World Health Organization said the outbreak appeared to be stabilising. (Photo by NOEL CELIS / AFP) (Photo by NOEL CELIS/AFP via Getty Images)

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A man wearing a protective face mask walks on an overpass in Lujiazui financial district in Shanghai on February 10, 2020. – The death toll from the novel coronavirus surged past 900 in mainland China on February 10, overtaking global fatalities in the 2002-03 SARS epidemic, even as the World Health Organization said the outbreak appeared to be stabilising. (Photo by NOEL CELIS / AFP) (Photo by NOEL CELIS/AFP via Getty Images)

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Delivering new services ‘complicated,’ Freeland says of planned dental care program

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OTTAWA — The government is working hard to meet its end-of-year deadline to deliver dental-care coverage to kids, the deputy prime minister said Tuesday, but added providing new services is “complicated.”

The Liberals agreed to offer dental coverage to low- and middle-income children by the end of the year as part of their confidence and supply deal with the New Democrats to keep the minority government from toppling before 2025.

Several groups have raised concerns about the very tight deadline, and four sources close to the program say the government is working on a temporary solution to give money directly to qualifying families while it comes up with a permanent program.

“As we experienced, for example, in rolling out child-care agreements across the country, delivering new services to Canadians is complicated,” Freeland said when asked about the stopgap plan at a news conference in Toronto.

“I think Canadians understand that.”

Freeland did not confirm or deny the government’s immediate plans but said the Liberals are committed to the dental-care program, and it’s a commitment she’s “happy to make.”

The government could pursue dental-care deals that resemble the ones it made with provinces to lower the cost of child care, in which it offered provincial governments money to administer their programs under a prescribed set of criteria. However, that route is looking increasingly unlikely.

Federal officials have also canvassed dental-health experts about other approaches. The government could contract out a national program to a private insurance firm or have federal public servants take on the work.

“Kids should not have their teeth get rotten just because their parents don’t have enough money to pay for them to go see a dentist, I think it’s as simple as that,” Freeland said.

The Liberals set aside $5.3 billion over five years to fully implement the program. They hope to start with children under the age of 12 with an annual household income of less than $90,000.

Last week NDP Leader Jagmeet Singh said he was confident the dental-care program would come together by the end of the year, as outlined in the agreement with the Liberals.

Freeland said the government is working “very, very hard” to make good on the promise to the NDP. The Liberals risk the NDP walking away from the supply and confidence agreement entirely if they don’t.

This report by The Canadian Press was first published Aug. 9, 2022.

 

Laura Osman, The Canadian Press

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Top commander defends military’s vaccine requirement, says ‘tweak’ in the works

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OTTAWA — Canada’s top military commander said he will “tweak” the vaccine mandate for the Armed Forces in the next few weeks but defended vaccine requirements as necessary to keep the military ready to respond to any emergency.

“This is an institution that’s unlike any other because we do have to be operationally ready, we are the nation’s insurance policy,” chief of the defence staff Gen. Wayne Eyre told The Canadian Press in an interview.

“We have to go into dangerous locations and close confined quarters, we have to deploy overseas, where there’s potentially an increased threat with the pandemic. We also don’t know the trajectory of this pandemic, where it’s going to go into the future.”

When Eyre ordered all troops vaccinated against COVID-19 last October, he said it was to both protect the force and “demonstrate leadership” as the Liberal government adopted vaccine mandates across the federal public service.

The public service vaccine mandate was suspended in June but the military one persists, a fact that has heightened criticism of the military’s policy.

The Department of National Defence said more than 98 per cent of Canadian troops complied with the order. Defence Minister Anita Anand was briefed in June that 1,137 remained unvaccinated.

Those who refuse vaccination face the risk of forced removal from the military. The department says 241 unvaccinated troops have been ousted with disciplinary measures initiated against hundreds more.

Eyre said he is trying to find the “sweet spot” between the military’s medical, legal, operational and ethical requirements.

“We need to maintain our operational viability going forward,” he said. “So over the course of the next number of weeks, we will tweak the policy, we’ll put out something amended. But we also need to realize that this is a dynamic environment, and things can change, the trajectory of the pandemic can change. So we’ve got to maintain that flexibility as well.”

He added that not only has the military been called upon to assist in communities across Canada that have been hit by the pandemic, but that vaccine requirements still exist in many allied and foreign nations and militaries.

The U.S. military still requires all troops to be vaccinated as do some NATO facilities and bases.

“There are going to be operational requirements where to operate with allies, (vaccination) is going to be essential,” he said. “But as we go forward, the options are being developed looking at those four factors that I talked about and finding the right balance.”

Eyre’s comments appear to contradict a draft copy of a revised vaccine policy obtained by the Ottawa Citizen last month, which suggested vaccine requirements for military personnel would be lifted.

The draft document, which officials say has not been approved by Eyre, said military personnel as well as new recruits would no longer have to attest to their vaccination status.

The document also noted potential legal difficulties ahead to deal with people who were kicked out of the military because of the vaccine mandate, suggesting they could be forced to apply for re-enrolment.

By contrast, other unvaccinated federal public servants were put on leave without pay but allowed to return to their jobs when the mandate was suspended.

The military mandate was unsuccessfully challenged several times in Federal Court, most recently last month.

Phillip Millar, the London, Ont.-based lawyer who appeared before the court to seek an injunction on behalf of unvaccinated service members, said the court ultimately decided it couldn’t rule on the issue until the new policy was released.

Millar, who is also representing James Topp, an army reservist charged with publicly speaking out against federal vaccine mandates while wearing his uniform, said he was disappointed with the decision given the lack of timeline for the new policy.

“The military is deliberately dragging its feet on this new direction because it just wants to kick people out,” Millar alleged, adding: “It’s obviously a political policy, not an operational policy.”

Eyre would not say whether Armed Forces members are still being kicked out, or whether such releases have been suspended pending the results of his review.

The Defence Department says there have been more than 9,500 cases of COVID-19 among military personnel, including 113 active cases as of Aug. 1. It did not say whether there have been any deaths associated with the illness.

This report by The Canadian Press was first published Aug. 9, 2022.

 

Lee Berthiaume, The Canadian Press

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Double mRNA COVID-19 vaccination found to increase SARS-CoV-2 variant recognition – News-Medical.Net

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In a recent study posted to the bioRxiv* preprint server, researchers evaluated the impact of double BNT162b2 messenger ribonucleic acid (mRNA) vaccination in recognition of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants of concern (VoCs).

Study: Double-dose mRNA vaccination to SARS-CoV-2 progressively increases recognition of variants-of-concern by Spike RBD-specific memory B cells. Image Credit: CKA/Shutterstock

Background

Studies have reported that double coronavirus disease 2019 (COVID-19) vaccinations generate high titers of SARS-CoV-2 S-targeted antibodies (Ab), Bmem and T lymphocytes; however, VoCs with SARS-CoV-2 S receptor-binding domain (RBD) mutations can evade humoral immune responses.

Booster doses have been reported to enhance VoC recognition by Abs; however, it is not clear whether VoC recognition is enhanced due to higher Ab titers or due to the increased capacity of Ab binding to S RBDs.

About the study

In the present study, researchers evaluated the benefit of double BNT162b2 vaccinations on SARS-CoV-2 VoC recognition.

Healthy and SARS-CoV-2- naïve persons (n=30) without immunological or hematological diseases were enrolled in the study to assess their peripheral blood B-lymphocyte subsets between February and June 2021.  Samples were obtained before the BNT162b2 vaccination, after three weeks of the first vaccination, and four weeks following the second vaccination.

Serum memory B lymphocytes (Bmem) counts and Ab titers were assessed using recombinant SARS-CoV-2 spike (S) protein RBDs of the Wuhan, Gamma, and Delta strains. Neutralizing Ab (NAb) titers were evaluated using 293T-ACE2 cells and SARS-CoV-2 pseudotyped viral assays. Further, the nature of RBD-targeted Bmem was examined based on the expression of cluster of differentiation (CD) 21, 27, and 71.

Enzyme-linked immunosorbent assays (ELISA) were performed to evaluate variant-specific S RBD antibody titers and the serum dilution needed for preventing 50% SARS-CoV-2 entry (ID50) values were ascertained. Flow cytometry (FC) was performed to evaluate Bmem counts. Immunoglobulin G (IgG) titers against SARS-CoV-2 nucleocapsid (N) protein RBD and S RBD were evaluated before and post the first and second BNT162b2 vaccination.

Results

In total, 28, 30, and 30 samples were obtained pre-vaccination, after three weeks of the first dose and after four weeks of the second dose, respectively. All the participants remained SARS-CoV-2-naïve throughout the study without anti-SARS-CoV-2 N antibodies. Most participants (n=22) induced NAbs after the first vaccination, and the NAb titers after the second vaccination had IC50 values >100.

Double BNT162b2 vaccination generated robust NAb responses among all study participants. Immunoglobulin G+ (IgG+) and IgM+ RBD-targeted Bmem were generated after the first vaccination, and IgG1+ Bmem counts increased after the second vaccination. Most RBD-targeted Bmem showed binding with Delta and/or Gamma VoCs, which increased significantly after the second vaccination.

The RBD-targeted Bmem compartment comprised mainly IgG1+ or IgM+ cells, and contrastingly, the total Bmem compartment comprised more IgG2+ cells and fewer IgG1+ cells compared to the RBD-targeted Bmem compartment.

After the second vaccination dose, RBD-targeted IgG1, 2 and 3-expressing Bmem populations expanded significantly, although the total Bmem lymphocyte compartment was unaltered.

The number of RBD-targeted IgG+ Bmem correlated positively with RBD-targeted serum IgG post first and second vaccinations. While two subsets of IgM+ Bmem lymphocytes (CD27+ IgM+ and CD27+ IgM+ IgD+) proportionally decreased after the second vaccination dose, the absolute cell counts were identical to those observed post the first vaccine dose. Taken together, BNT162b2 vaccinations particularly affected the antigen-targeted Bmem lymphocyte counts, and the production of IgG1-expressing Bmem lymphocytes was boosted after the second BNT162b2 vaccination.

CD27 was expressed by 95% of anti-RBD and IgG-expressing Bmem lymphocytes, the proportion of which did not differ between the initial and subsequent BNT162b2 vaccination. After the first vaccine dose, 15% of anti-RBD Bmem lymphocytes were CD21lo, the proportion of which was marginally but significantly lower (reduced to 10%) after four weeks of the second vaccination.

CD71 was expressed by 10% of anti-RBD Bmem lymphocytes after the first and second vaccination. In the total population of Bmem lymphocytes, the results after the first and second vaccination did not differ significantly, denoting the Bmem compartment stability. After four weeks of vaccination, anti-RBD Bmem lymphocytes exhibited a nature and resting Bmem lymphocyte immunophenotype.

Anti-Wuhan S RBD- IgG titers exhibited partial recognition of the Beta, Gamma and Delta VoCs with more prominent reductions for Gamma and Beta VoCs than for the Delta VoC. The second vaccine BNT162b2 dose significantly enhanced anti-Wuhan RBD antibody binding to Gamma and Beta VoCs; however, the neutralization potency of vaccine-induced NAbs against Gamma and Beta was lesser than for Delta.

Delta RBD and Gamma RBD were recognized by 50% and 70% of RBD-targeted Bmem lymphocytes after the first and second vaccinations, respectively, and the increase in VoC-recognizing Bmem counts was largely due to elevated IgG1+ Bmem counts.

Conclusion

Overall, the study findings showed that the second BNT162b2 vaccination elevated NAb titers and SARS-CoV-2 RBD-targeted Bmem counts and that double BNT162b2 vaccination was especially needed for Delta and Gamma VoC recognition. The findings indicated that the second vaccine dose improved S RBD-targeted Bmem counts and the Bmem affinity to overcome VoC mutations.

*Important notice

bioRxiv publishes preliminary scientific reports that are not peer-reviewed and, therefore, should not be regarded as conclusive, guide clinical practice/health-related behavior, or treated as established information.

Journal reference:

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