A Harvard University review found issues with each of 10 studies on hydroxychloroquine they examined. The drug can be immunosuppressive, which could be helpful or harmful for covid patients.

Data from a project led by University of Oxford researchers shows that Britain's rate of 394 deaths per million is the fourth worst in world behind Italy, Spain and Belgium.

More than 90% of COVID-19 patients treated with hydroxychloroquine in studies in France and Boston had longer than normal pauses in their heart beats - a sign of dangerous arrhythmias.

DR MICHAEL MOSLEY: Like many, I've long believed that our relentless use of social media is, for want of a better term, rotting our brains.

Evidence suggests the biggest risk factor for death by Covid-19 is age, but scores of pensioners are bucking the trend by managing to shake off the killer infection.

EVE SIMMONS: Becoming infected with coronavirus undoubtedly tops the list of current health fears for most Britons. But getting fat seems to come a close second.

DR MARTIN SCURR: Any persistent problem can be terribly frustrating but it is not the Barrett's oesophagus (pictured) that is causing your symptoms.

New research has shown that our response to infection changes over the course of each day, and - even more importantly - that sleep disruption can leave our immune system compromised (file photo).

The malaria-blocking bug, Microsporidia MB, was found by University of Glasgow scientists in the gut and genitals of mosquitoes living on the shores of Lake Victoria in Kenya.

A walk in the park could cause hayfever sufferers to sneeze, even if the pollen count is low, a US-German study has found. Research on 25 men found even a simple smell could trigger hayfever symptoms.

History shows how lethal disease pandemics have a habit of seeming to shrink away - but then returning suddenly in subsequent waves. Chillingly, these latter waves can prove far deadlier.

One sample collected from an Arizona coronavirus patient showed a deletion of 81 genetic 'letters' that suppresses the virus's ability to fight the human immune system, also seen as SARS began to fade.

Researchers at the London School of Economics have highlighted exactly where the UK has fallen short of protecting some 400,000 care home residents and staff.

An urgent review has been launched by Health Secretary Matt Hancock into whether obesity, ethnicity and gender raise the risk of death from coronavirus.

Defra confirmed it is conferring with scientists about whether wastewater can help trace the spread of the deadly infection. It could become part of the government's plan to ease Britain out of lockdown.

Sir Patrick Vallance told MPs on the Health and Social Care Select Committee that masks could have a 'marginal but positive' impact on curbing transmission of the life-threatening infection.

British researchers modelled how the virus would spread in three scenarios - if Italy stayed in quarantine or if movement returned to pre-lockdown levels by 20% and 40% (shown in red).

The UK's death toll (29,427) surpassed Italy's (29,315) today, meaning it is the worst-hit nation on the continent. But, even now, Britain's borders remain open, making it a global outlier.

The two party leaders clashed over the pandemic as they faced each other for the first time at Prime Minister's Question in the hushed surroundings of the mostly-empty House of Commons.

Experts at Florida Atlantic University conducted an experiment using a mannequin and laser lights. Health officials recommend a safe distance of six feet (two metres).

Some institutions have said that if their coronavirus vaccine trials go well, its jab could be available as early as Fall 2020, but most people would not be able to get it until Fall 2021.

Scientists in Italy claim antibodies made against the virus in mice were able to kill the infection in human cells, but British researchers said the discovery was routine in vaccine development.

Scientists in Glasgow trawled over data for more than 428,000 people who were part of the UK Biobank. Some 340 of those had recently tested positive for COVID-19 in hospital.

Experts say the vulnerability of health systems in Eastern Europe spurred leaders into decisive action while governments in the west felt a 'greater sense of complacency'.

SIR CLIVE WOODWARD: Eddie Jones faces some of the toughest decisions of his coaching career on Monday when he names his World Cup squad. He will never forget the calls he makes.

SIR CLIVE WOODWARD: England missed out on the scoreboard in Cardiff - and they missed a huge learning opportunity. What did they gain from the match? Not much. What did they learn? Not much.

The Rugby World Cup is just round the corner and Sportsmail has everything you need to know. SIR CLIVE WOODWARD has the lowdown on every team in the tournament in Japan.

SIR CLIVE WOODWARD: Everything is coming to the boil nicely and sometime soon this England side is going to produce a performance for the ages. This Saturday would be the perfect time.

SIR CLIVE WOODWARD: Many wrote off Wales's World Cup chances after their narrow victory over France last week. But now I believe they will beat South Africa to reach their first final.

SIR CLIVE WOODWARD: England have taken Ireland to the cleaners twice in the past 12 months, but only one of those victories counted for a bean and that was in Dublin 12 months ago.

SIR CLIVE WOODWARD: When Bill Beaumont clocks back on Monday morning, it would be worth remembering that, although the official tally says 28-23, he actually won by only one vote.

From a design point of view, the shell (still) looks like a pregnant, stretched 911-shaped whale, which I (still) can’t believe anyone finds attractive – but I know they do

Back in the late 1960s and early 1970s, the A110 was a doyenne of its genre, taking the constructor’s title in the 1973 World Rally Championship. Original cars remain much-loved classics

Compared to last week’s all-our Christmases-have-come-at-once-Bentley, I thought the A 200 was going to be a run-of-the-mill, practical and prosaic affair. Well, not so

Tash, myself and our boys, Noah and Eli, however, have been involuntarily thrust into the land of seven-seater giants in what is becoming an increasingly more urgent situation

The Kodiaq it doesn’t feel like an ungainly monster out on the road. You’re high up but not so high up you might encounter a bird strike or feel like you’re looking down your nose at the rest of the world

The Champions League returned with a bang this week as Borussia Dortmund, Atletico Madrid and RB Leipzig took huge steps towards three big upsets.

JAMIE REDKNAPP: If Mourinho needs a striker, then he could do worse than look at Troy Parrott. He's been training with the first team, learning from the master Kane and has been capped by Ireland.

Jose Mourinho ramped up the mind games for Tottenham's clash at Chelsea by suggesting he knows Frank Lampard's tactics for Saturday's Premier League match.

Sportsmail looks at whether Chelsea or Tottenham are better equipped to secure a Champions League spot ahead of their meeting at Stamford Bridge on Staurday afteroon.

Does anyone want to qualify for the Champions League Based on the current standings, it appears not. Chelsea have the joint-lowest total for a fourth placed side at this stage since 2003-04.

Chelsea earned a vital win over Tottenham at Stamford Bridge in Premier League action.

Dele Alli reacted angrily to his 64th minute substitution during a 1-0 Champions League defeat to RB Leipzig on Wednesday. The England international has now been dropped to the bench.

MATT BARLOW AT STAMFORD BRIDGE: Mourinho summoned Ndombele and was hoping to get a 'good hour' out of him. It was impossible to describe his hour as a good one.

OLIVER HOLT AT STAMFORD BRIDGE: Any Spurs fans - or players - expecting a rallying cry after a significant setback like this would have been sorely disappointed.

Who'd have thought Jose Mourinho would have left a legacy at Old Trafford after all? Mourinho signings Nemanja Matic and Fred have been very important in their recent success.

There was a glint in Pep Guardiola's eye as he talked about Real Madrid, as European football's most influential coach gets ready to tackle its ultimate winning machine.

JAMIE REDKNAPP: We look at VAR as if it's the oracle but in reality it's one man, sat behind a bank of screens at Stockley Park, offering his opinion. It's not matter of fact - it's subjective.

The Premier League once again treated spectators to twists and turns galore, and here are 10 things we learned from all the action this weekend.

PETE JENSON IN SPAIN: Manchester City left empty handed on the dramatic night in 2012 after a sensational late 3-2 win for Real Madrid brought manager Jose Mourinho to his knees.