Human study supports theory on why dengue can be worse the next time around

Et tu, antibody? In humans, dengue can be more severe the second time around. Now, a study implicates an immune system treachery as the culprit.

The study suggests that the amount of anti-dengue antibodies a person has matters. In a 12-year study of Nicaraguan children, low levels of dengue antibodies left over in the blood from a prior infection increased the risk of getting a life-threatening form of the disease the next time around, researchers report online November 2 in Science.

Four related viruses cause dengue. The theory that antibodies protective against one type of dengue can collude with a different type of the virus to make a second infection worse was proposed in the 1960s. Such antibody-dependent enhancement has been shown in cells and lab animals. But “there’s been this controversy for five decades about, does this antibody-dependent enhancement really happen in dengue” in humans, says coauthor Eva Harris, a viral immunologist at the University of California, Berkeley’s School of Public Health. “And this says, yes, it does.”

About 2.5 billion people live where there is a risk of dengue infection. The virus infects 50 million to 100 million people every year, the World Health Organization estimates, but many cases go unreported. Infection with the mosquito-transmitted virus often leads to no symptoms, but can cause fever, joint and muscle pain and other flulike symptoms. The most severe form, which affects about half a million people annually, can include internal bleeding, respiratory distress or organ failure, and may be fatal.
Getting sick with one of the four virus types can protect against a future infection of the same type. But in some cases, the theory goes, leftover antibodies from the first illness can actually help the second infection invade cells, increasing the risk of severe dengue disease.

“This study provides support for this idea that antibodies under certain conditions can be bad and actually cause severe disease when people are infected with dengue,” says viral immunologist Sujan Shresta of the La Jolla Institute for Allergy and Immunology in California. The next step, she says, is to learn more about the antibodies involved and see whether the findings hold up in other populations.

From 2004 to 2016, Harris and her colleagues studied more than 6,500 children aged 2 to 14 in Managua, Nicaragua. The researchers took blood samples each year, at a time when the kids were healthy, and assessed their antibody levels. The scientists also monitored which kids developed dengue and how severe the disease was.

An analysis showed that kids with a specific low range of anti-dengue antibodies had around a 7½ times higher risk of developing the most severe form of the disease than those who had either no antibodies or a high amount. The team’s test couldn’t tell what kind of dengue antibodies each child had. Harris and colleagues are now working on characterizing the antibodies measured in their test, to learn what makes them protective or harmful.

The new study supports the theory of antibody-dependent enhancement in humans, says Anna Durbin, an infectious diseases physician at Johns Hopkins Bloomberg School of Public Health. But she also argues that the risk of developing severe disease depends on the quality of the antibody — that is, how potent it is — as much as, or more than, the quantity. “A number in and of itself doesn’t tell you a whole lot.”

Terence Crawford vs. Shawn Porter results: Crawford retains WBO welterweight title with 10th-round stoppage

LAS VEGAS — All the questions about Terence Crawford have been answered.

For years, the only knock on him was that he lacked a signature victory. He finally picked up one — and in exceptional fashion — when he became the first fighter to stop Shawn Porter, recording a 10th-round TKO to retain his WBO welterweight championship in front of 11,568 fans at Michelob ULTRA Arena.
Now, the world will be clamoring for a unification bout with IBF and WBC champion Errol Spence Jr.

As it always has been against Porter, winning didn't come easy.

At the time of the stoppage, Crawford was up on all three scorecards: 86-85, 86-85 and 87-84. Porter routinely barreled inside and kept Crawford off balance with aggression and pressure. But Crawford began to time Porter's advances and then picked him off with counters that eventually wore down the former two-time champion.

In the 10th round, Crawford opened with a thudding left hand that deposited Porter on his backside. A frustrated Porter made it to his feet but was met with a scintillating combination that dropped Porter to his knees. Porter pounded on the canvas out of frustration and made it back to his feet again. Unfortunately, his father and trainer, Kenny Porter, decided that his son had had enough and threw in the towel.

Crawford improved to 38-0 with 29 knockouts. Porter became his ninth consecutive knockout victim. As for Porter, his career is at a crossroads of sorts as he falls to 31-4-1 and goes to the back of the line when it comes to title opportunities.

Here's how it all went down in Las Vegas.

Terence Crawford vs. Shawn Porter live updates, highlights
(All times Eastern.)

Round 10 (12:15 a.m.): Crawford drops Porter with a left hand to open the round! Porter is up and Crawford is a killer. He’s looking to finish the job. Crawford with a barrage that drops Crawford. Porter beats the canvas on his way up. Porter’s corner stops it! Wow!

Round 9 (12:13 a.m.): Short left hand by Porter lands to open the round. Big hook by Porter barely lands. Bud is unbothered. Body shot by Porter. Crawford looking for his spots and Porter isn’t making it easy. Crawford lands an uppercut on the inside and a body shot. 10-9, Crawford (86-85, Crawford)

Round 8 (12:09 a.m.): Crawford with a hard right hand and Porter comes straight at him throwing bombs. Crawford avoids and picks him off with a right hand. Beautiful sequence by Bud. Porter chops him on the inside with a short left and barrels inside. Hard left hand by Porter. Big right hand by Porter rattles Crawford. Crawford smiles and centers himself. How do you score this round? 10-9, Crawford (76-76)

Round 7 (12:04 a.m.): Porter strafes Bud with a left hand. Crawford gives Porter different looks and feints. They exchange left hands. Right hand by Porter lands and Crawford bounces off the ropes. Short counter right by Crawford as Porter rolls in. Porter won’t stop coming. Bud is smiling again. But he’s not throwing enough. 10-9, Porter (67-66, Porter)

Round 6 (12:01 a.m.): Crawford lands a big right hand They are going to war again. Crawford looking for the big shot and loading up. Porter comes roaring back. They clash heads. Crawford looks like he’s enjoying the dog fight. Porter roughs him up on the inside. Man, this is a damn fight. Counter left on the inside by Crawford. Lots of infighting to close a tight round. 10-9, Crawford (57-57)

Round 5 (11:57 p.m.): Porter working on Bud from the inside with some roughhousing. Crawford trying to walk Porter down. Flashes the jab. Porter bombing away on Crawford as he covers up. Not a lot gets through. Crawford walking him down. Porter is just outworking him in this round but Crawford is hoping he spent up his gas tank. 10-9, Porter (48-47, Porter)

Round 4 (11:52 p.m.): Hard left hook from Porter to open the round. Crawford lands a combination and a left hand. They exchange hard shots. Porter lands a right hand and Bud smiles. Porter with a jab and Bud responds to the body. Porter with a lunging hook that lands. Crawford with a check hook that almost Ricky Hatton'd Porter. They start swinging again. Closer round. 10-9, Crawford (38-38)

Round 3 (11:48 p.m): Crawford looks comfortable fighting lefty. Starts pushing Porter back. Porter lands a hard combination. Crawford tried to time and barely missed a counter hook. Porter stuns Bud with a left hand! Bud smiles but he was cracked. They are talking now. Porter is cut over the right eye. Crawford smiling but he knows that he's now in a fight. 10-9, Porter (29-28, Porter)

Round 2 (11:44 p.m.): Porter lands a jab and Bud switches to southpaw. Barely misses a counter. Lands a hard right hand on Porter. Porter cracks Bud with a hard right hand in response. Crawford lands a right hand and barely misses an uppercut. A firefight breaks out. Both landing hard shots. Bud with a counter uppercut and Porter with a right hand. Crawford lands the jab and smiles. We're about to have a good one. 10-9, Crawford (19-19)

Round 1 (11:40 p.m.): Porter rushes right at Crawford with a left hook and follows with a right hand that lands. Porter aims to rough Bud up along the ropes and gets tied up. Crawford is reading and timing Porter. Starts to fire the jab. Left hand by Porter lands. Hard jab by Bud lands. Crawford smirks at Porter. He may have figured out something already. 10-9, Porter

11:30 p.m.: "Showtime" Shawn Porter makes his entrance with WWE champion Big E and Grammy-nominated Hip Hop artist Rapsody while Terence Crawford keeps it simple by walking alone to LL Cool J's "I'm Bad."

10:58 p.m.: Through six rounds, Esquiva Falcao, the 2012 Olympic silver medalist from Brazil, has been applying immense pressure to Patrice Volny. Volny tried to work from the outside but Falcao's persistence to throttle Volny from the inside racked up rounds. But a nasty clash of heads in the sixth round split Falcao open above the left eye. Falcao is in a lot of pain and it's likely this fight is going to be stopped. Yup, it's over. Main event is next.

10:22 p.m.: Janibek Alimkhanuly didn't have much trouble turning back the challenge of Hassan N'Dam. He chopped him down over the course of eight rounds to earn the TKO stoppage. N'Dam's best years as a contender are clearly behind him, while Alimkhanuly remains one to watch in the middleweight division. As the rounds wore on, it became target practice for Alimkhanuly. N'Dam offered little resistance and was routinely clocked by power punches and a hard left hand. The mounting damage was too much for referee Kenny Bayless and the fight was called at the 2:40 mark of the eighth.

9:37 p.m.: As expected, Muratalia mowed down Araujo with an exceptional display of body punching and aggression to pick up the fifth-round TKO.

9 p.m.: We're live from Las Vegas and the pay-per-view portion of Crawford-Porter will kick off with Raymond Muratalla and Elias Araujo competing in a lightweight showdown.

Terence Crawford vs. Shawn Porter start time
Date: Saturday, Nov. 20
Main card time: 9 p.m. ET | 6 p.m. PT
Main event: 11 p.m. ET | 8 p.m. PT (approx.)
Crawford and Porter are set to step into the ring at about 11 p.m. ET. The night will begin with early prelims at 6 p.m. ET, followed by the prelim card at 7 p.m. ET and the main card at 9 p.m. ET.
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College football overtime rules 2021: Explaining how the new OT format works

Overtime is going to look a little bit different in college football games during the 2021 season. The NCAA has once again made some minor tweaks to its overtime rules.

Why? It's all in the name of bringing the game to a quicker conclusion.
The NCAA has made shortening overtime its mission since Texas A&M beat LSU 74-72 in a seven overtime game during the 2018 season. As exciting as that game was, it was long. More than 200 snaps were played, which is certainly not ideal for the players on the field.

So, how is the NCAA changing its overtime rules for 2021? Here's everything you need to know about the differences in overtime this season and how it compares to previous seasons.
College football overtime rules 2021
The NCAA amended its overtime rules in 2021 in an attempt to lessen the number of plays run in an overtime period. Teams are now required to run a two-point conversion after a touchdown beginning in the second overtime period. Previously, that began in the third overtime period.

Additionally, teams will begin running alternating two-point conversion attempts if the game reaches a third overtime. So, it's essentially a one-play drive. The goal of this is to limit the number of plays run from scrimmage by each team.

Here are the rest of the college football overtime rules for the 2021 season.

At the end of regulation, the referee will toss a coin to determine which team will possess the ball first in overtime. The visiting team captain will call the toss. The winner gets to choose to either play offense or defense first or chooses which side of the field to play on. The decision cannot be deferred.
The teams that loses the coin toss must exercise the remaining option. They will then have the chance to choose first from the four categories in the second overtime and subsequent even-numbered OT periods. The team that wins the toss will have the same options in odd-numbered OT periods.
In each of the first two overtime periods, teams are granted one possession beginning at the opponent's 25-yard line, unless a penalty occurs to move them back. The offense can place the ball anywhere on or between the hash marks.
Each team is granted one timeout per overtime period. Timeouts do not carry over from regulation nor do they carry over between overtime periods.
Each team retains the ball until it fails to score, fails to make a first down or turns the ball over.
Beginning with the second overtime period, teams must attempt a two-point conversion after scoring a touchdown.
Beginning with the third overtime period, teams will begin to run alternating two-point conversion plays instead of offensive possessions.
The college football overtime rules are the same in both the regular and postseason.
College football overtime rule change proposals
The most recent overtime rule change proposal was passed by the NCAA in 2021. It was made in the name of shortening games and limiting offensive reps, as previously stated.

Below are the rule changes that were ratified for 2021:

Beginning with the second overtime period, teams must attempt a two-point conversion after scoring a touchdown.
Beginning with the third overtime period, teams will begin to run alternating two-point conversion plays instead of offensive possessions.
History of college football overtime rules
Up until 1996, most NCAA games did not go to overtime. They simply ended in a tie. However, the governing body adopted overtime rules after pushback on some important matchups ending all square.

The initial overtime rules were in place for quite a while. Each team got the ball at the opponent's 25-yard line and retained the ball until it failed to score, failed to make a first down or turned the ball over. Teams alternated possessions until a team emerged as a victor.

Then, in 2019, the NCAA made a couple of changes in the name of shortening the game. That's when they added the two-point conversion rule, so teams had to start attempting a two-point conversion starting in the third overtime. Then, after five overtimes, teams would start running alternating two-point conversion plays. These changes were, basically, a direct response to the Texas A&M vs. LSU game.

In 2021, the rules were tweaked again, as teams must run two-point conversions in the second overtime period and will begin alternating two-point plays when the third overtime begins.

Luka Doncic injury update: Mavericks superstar listed as doubtful against Suns with ankle injury

A big win over the Denver Nuggets was soured for the Dallas Mavericks in the final minute when Luka Doncic appeared to suffer an ankle injury.

After the game against Denver, Doncic is averaging 24.9 points, 8.3 rebounds and 7.9 assists on the season.

What's next for Doncic? Here's everything we know about his injury and the latest news on when he may return to the court.
What is Luka Doncic's injury?
The injury was sustained as the Mavericks superstar attempted to block an Austin Rivers layup. Rivers' body appeared to roll over the ankle of Doncic in the aftermath of the play.
The win improved Dallas to 9-4 on the season, good for third in the Western Conference.

Doncic was his usual dominant self in the win, finishing with 23 points, eight rebounds, 11 assists, two steals and a block across 37 minutes of play.

How long will Luka Doncic be out?
Doncic was unavailable for media postgame as he was undergoing treatment, with head coach Jason Kidd unable to give an immediate update.

“Luka walked off on his own power,” Kidd said.

“I think he got his lower left leg rolled up on, so we’ll see how he feels.”

The following day, The Athletic's Shams Charania reported that tests on Doncic's left ankle and knee "showed no damage." ESPN's Tim MacMahon added that his injury is believed to be "not too serious" and that he'll likely miss some time but hopefully not an extended stretch.

Doncic sat out the Mavs' loss to the Phoenix Suns on Nov. 17 and is doubtful for the team's rematch on Nov. 19.

Mavericks upcoming schedule 2021-22
Date Opponent Time (ET)
Fri, Nov. 19 at Phoenix 10:00 PM
Sun, Nov. 21 at LA Clippers 3:30 PM
Tue, Nov. 23 at LA Clippers 10:30 PM
Sat, Nov. 27 vs. Washington 8:30 PM
Mon, Nov. 29 vs. Cleveland 8:30 PM
Wed, Dec. 1 at New Orleans 8:00 PM
Doncic has been a durable player throughout the early portion of his career, playing all 13 games this season so far, after missing just six across the 72-game regular season in 2020-21.

Stay tuned for further updates from the team on the status of Doncic and his ankle.

CONCACAF 2022 World Cup Qualifying: Schedule, standings, TV for soccer Octagonal

We're now into the second half of the qualifying schedule and it's Canada at the top of the CONCACAF 2022 World Cup qualifying standings.

A 2-1 home win over Mexico allowed the Canadians to overtake the USA atop the eight-team table. Canada is the only remaining unbeaten team in qualifying as it continues to push to qualify for its first World Cup since 1986.

The USA (2nd, 15 points) and Mexico (3rd, 14 points), long the powers of the region, are now chasing. Meanwhile, Panama continued its surge with another dramatic come-from-behind victory to go level with Mexico on 14 points. The top three teams earn automatic berths to the World Cup, while fourth-place earns passage to a play-in series for one of the final spots in Qatar 2022.

The other half of the table is in precarious position. A group of three teams — Costa Rica (5th), Jamaica (6th), El Salvador (7th) — is now between 5-8 points behind Panama for fourth place. Meanwhile, it's looking unlikely that Honduras will be able to recover from its last-place point total. 

The first standings tiebreakers are (1) goal difference, (2) goals scored and (3) most points obtained from matches between teams that are tied. The full list of tiebreakers and results for Matchdays 1-7 follow at the bottom of this post.

CONCACAF World Cup Qualifying Standings & Results
Team PTS GP W L D GF GA GD

  1. Canada 16 8 4 0 4 13 5 +8
  2. USA 15 8 4 1 3 12 5 +7
  3. Mexico 14 8 4 2 2 11 7 +4
  4. Panama 14 8 4 2 2 11 9 +2
  5. Costa Rica 9 8 2 3 3 6 7 -1
  6. Jamaica 7 8 1 3 4 6 10 -4
  7. El Salvador 6 8 1 4 3 4 10 -6
  8. Honduras 3 8 0 5 3 5 15 -10
    Matchday 8
    Date Match
    Tues, Nov. 16, 2021 Jamaica 1 , USA 1 Highlights
    Tues, Nov. 16, 2021 Costa Rica 2 , Honduras 1 Highlights
    Tues, Nov. 16, 2021 Panama 2 , El Salvador 1 Highlights
    Tues, Nov. 16, 2021 Canada 2, Mexico 1 Highlights
    Matchday 9
    Date Match Time (ET) Stream
    Thurs, Jan. 27, 2022 Honduras vs. Canada TBD TBD
    Thurs, Jan. 27, 2022 USA vs. El Salvador TBD TBD
    Thurs, Jan. 27, 2022 Costa Rica vs. Panama TBD TBD
    Thurs, Jan. 27, 2022 Jamaica vs. Mexico TBD TBD
    Matchday 10
    Date Match Time (ET) Stream
    Sun, Jan. 30, 2022 Canada vs. USA TBD TBD
    Sun, Jan. 30, 2022 Honduras vs. El Salvador TBD TBD
    Sun, Jan. 30, 2022 Mexico vs. Costa Rica TBD TBD
    Sun, Jan. 30, 2022 Panama vs. Jamaica TBD TBD
    Matchday 11
    Date Match Time (ET) Stream
    Wed, Feb. 2, 2022 El Salvador vs. Canada TBD TBD
    Wed, Feb. 2, 2022 USA vs. Honduras TBD TBD
    Wed, Feb. 2, 2022 Mexico vs. Panama TBD TBD
    Wed, Feb. 2, 2022 Jamaica vs. Costa Rica TBD TBD
    Matchday 12
    Date Match Time (ET) Stream
    Thurs, March 24, 2022 Costa Rica vs. Canada TBD TBD
    Thurs, March 24, 2022 Panama vs. Honduras TBD TBD
    Thurs, March 24, 2022 Jamaica vs. El Salvador TBD TBD
    Thurs, March 24, 2022 Mexico vs. USA TBD TBD
    Matchday 13
    Date Match Time (ET) Stream
    Sun, March 27, 2022 Canada vs. Jamaica TBD TBD
    Sun, March 27, 2022 Honduras vs. Mexico TBD TBD
    Sun, March 27, 2022 El Salvador vs. Costa Rica TBD TBD
    Sun, March 27, 2022 USA vs. Panama TBD TBD
    Matchday 14
    Date Match Time (ET) Stream
    Wed, March 30, 2022 Panama vs. Canada TBD TBD
    Wed, March 30, 2022 Jamaica vs. Honduras TBD TBD
    Wed, March 30, 2022 Mexico vs. El Salvador TBD TBD
    Wed, March 30, 2022 Costa Rica vs. USA TBD TBD
    CONCACAF World Cup Qualifying results & highlights
    Matchday 1
    Date Match
    Thurs, Sept. 2, 2021 Canada 1, Honduras 1 Highlights
    Thurs, Sept. 2, 2021 Panama 0, Costa Rica 0 Highlights
    Thurs, Sept. 2, 2021 Mexico 2, Jamaica 1 Highlights
    Thurs, Sept. 2, 2021 El Salvador 0, USA 0 Highlights
    Matchday 2
    Date Match
    Sun, Sept. 5, 2021 Jamaica 0, Panama 3 Highlights
    Sun, Sept. 5, 2021 Costa Rica 0, Mexico 1 Highlights
    Sun, Sept. 5, 2021 El Salvador 0, Honduras 0 Highlights
    Sun, Sept. 5, 2021 USA 1, Canada 1 Highlights
    Matchday 3
    Date Match
    Wed, Sept. 8, 2021 Canada 3, El Salvador 0 Highlights
    Wed, Sept. 8, 2021 Panama 1, Mexico 1 Highlights
    Wed, Sept. 8, 2021 Costa Rica 1, Jamaica 1 Highlights
    Wed, Sept. 8, 2021 Honduras 1, USA 4 Highlights
    Matchday 4
    Date Match
    Thurs, Oct. 7, 2021 USA 2, Jamaica 0 Highlights
    Thurs, Oct. 7, 2021 Honduras 0, Costa Rica 0 Highlights
    Thurs, Oct. 7, 2021 Mexico 1, Canada 1 Highlights
    Thurs, Oct. 7, 2021 El Salvador 1, Panama 0 Highlights
    Matchday 5
    Date Match
    Sun, Oct. 10, 2021 Panama 1, USA 0 Highlights
    Sun, Oct. 10, 2021 Jamaica 0, Canada 0 Highlights
    Sun, Oct. 10, 2021 Costa Rica 2, El Salvador 1 Highlights
    Sun, Oct. 10, 2021 Mexico 3, Honduras 0 Highlights
    Matchday 6
    Date Match
    Wed, Oct. 13, 2021 USA 2, Costa Rica 1 Highlights
    Wed, Oct. 13, 2021 Canada 4, Panama 1 Highlights
    Wed, Oct. 13, 2021 Honduras 0, Jamaica 2 Highlights
    Wed, Oct. 13, 2021 El Salvador 0, Mexico 2 Highlights
    Matchday 7
    Date Match
    Fri, Nov. 12, 2021 Honduras 2 , Panama 3 Highlights
    Fri, Nov. 12, 2021 USA 2 , Mexico 0 Highlights
    Fri, Nov. 12, 2021 Canada 1 , Costa Rica 0 Highlights
    Fri, Nov. 12, 2021 El Salvador 1 , Jamaica 1 Highlights
    How CONCACAF World Cup Qualifying works
    Eight nations from the CONCACAF region (North America, Central America and the Caribbean) are competing for three automatic berths to the 2022 Qatar World Cup in the final "octagonal" qualifying round.

The eight countries are facing off in a round-robin format with each team playing the other seven opponents once at home and once on the road. The 14 total matches for each national team began in September 2021 and will wrap up in March 2022.

The top three finishers will earn automatic berths to Qatar, while the fourth-place team will head to an intercontinental playoff with a final ticket to Qatar on the line. Here are the standings tiebreakers for teams even on points:

Goal difference in all group matches
Most goals scored in all group matches
Most points obtained from group matches between teams concerned
Goal difference from group matches between teams concerned
Most goals scored in group matches between teams concerned
Goals scored away from home (if two teams tied)
Discipline points (based on yellow/red cards)
Drawing of lots by FIFA
The Qatar World Cup will be played from Nov. 21 to Dec. 18, 2022.