New Covid-19 UK variant can be deadlier than the previous strain

People sick with the Covid-19 variant had a higher viral load (more virus in their body), which was linked to a more severe coronavirus sickness.

The new variant is also more transmissible, meaning more infections that may ultimately result in a higher death toll.

UK Prime Minister Boris Johnson announced a week ago that people infected with the new coronavirus variant faced a higher risk of death compared to those infected by the original virus.

"There is some evidence the new variant may be associated with a higher degree of mortality," he said at a press conference on Friday.

The new variant, dubbed B.1.1.7, was quickly found to be more contagious than the original virus. But evidence of this was in short supply until now.

"Where an average of 10 out of a 1,000 older people died of the old variant in the UK, this appears to have increased to 13 out of 1,000 people with the new variant," says Patrick Vallance, British Chief scientific advisor said on Friday. 

Some experts disagree with this view, noting that just because more people infected are dying does not necessarily mean the virus is more lethal, instead citing the overtaxed health system in the UK. Another alternative view suggested that the virus’s higher transmissibility made it more of a threat to people with pre-existing health issues.

30 per cent higher mortality rate

A study analyzing differences in mortality between covid-19 strains found that on average, groups of patients with B.1.1.7 had 30 per cent more deaths.

A follow-up finding shared by Public Health England found that B.1.1.7 was 65 per cent deadlier than other coronavirus strains. University of Exeter researchers found that people infected with the variant were nearly twice as likely to die. 

No evidence was found by any of the researchers that B.1.1.7 was increasing hospitalization rates.

The World Health Organization is taking precautions, announcing that it still needed to see the UK data showing that the new variant actually causes a more severe infection.

One reason why the strain may be more lethal is the higher viral load it causes, meaning victims produce more viral particles when sick, which in turn explains its higher contagiousness.

Another possible reason is that the virus is more transmissible, causing more normal deaths even though the variant is not deadlier. The B.1.1.7 variant underwent several mutations of its spike protein, which makes it more contagious than the original.

Another possibility is that the UK’s healthcare infrastructure is heavily overburdened, causing more death rates.

"If your cases get out of control, your deaths will get out of control as your health system comes under pressure," Mike Ryan, executive director of the WHO's health emergencies program said in a press conference on Friday.

The verdict is still out because the findings only looked at 8 per cent of total deaths during the study’s period, requiring further studies for stronger evidence.

Normal covid-19 tests don’t identify which variant is responsible for killing a patient. It requires a time-consuming blood or saliva test, which is not always done.

The research also acknowledges that it did not adjust its data for underlying health conditions in mortality cases.

Adam Kucharski, epidemiologist at the London School of Hygiene and Tropical Medicine, presented three possible scenarios on Twitter regarding the new virus variant.

Assuming the original strain of the coronavirus has a reproductive value (meaning the average number of people one sick person infects) of 1.1 and kills 0.8 of every 100 who get sick, out of 10,000 people the virus would normally kill 129 people a month.

But in the event that two new covid-19 strains emerged, one 50 per cent deadlier, while the other is 50 per cent more transmissible, then the 50 per cent more lethal strain would kill nearly 193 out of 10,000 people in a month. The 50 per cent more transmissible strain would still end up killing 978 of 10,000 people because of how fast it spreads.