How much more transferable is the new variant of the coronavirus?

The new SARS-CoV-2 variant that first appeared in southern England has a transmission advantage of 0.4 to 0.7 points higher in reproduction number, also known as R0, compared to the original strain, British researchers found.

This variant, dubbed 202012/01, has a ‘substantial transmission advantage,’ meaning that reproduction numbers can range from 1.4 to 1.8, according to a multidisciplinary team from Imperial College London (ICL), which published their findings on the website .

Led by Erik Volz, PhD of ICL, the team found a “large and statistically significant imbalance” in regions where the incidence of the variant increased and the incidence of the non-variant decreased, and vice versa, which would indicate a change in R0.

Volz and colleagues also noted a higher proportion of persons under 20 years of age among the reported cases of the variant versus non-variant cases, calling this “a shift in age composition.” They estimate that the R0 of the variant is 40% -80% higher than that of the wild-type virus.

For context in the US, previous research found that seasonal flu had a median reproduction number of 1.28, while the median reproduction number for the 1918 flu pandemic was 1.80.

This variant has already traveled across the pond, with a Colorado man as the first documented case in the US last week, although reports of the variant surfaced in other states during the holidays, including California and Florida.

CDC officials informed reporters about the variant on Wednesday, noting that it seems unlikely to affect the effectiveness of the COVID-19 vaccine, although it may make certain treatments less effective, such as restorative plasma. The agency says it expects more data on the variant soon.

A preliminary report from the UK Center for Mathematical Modeling of Infectious Diseases on December 23, originally estimated transmission, could be at least 56% and up to 70% higher. They updated their findings on Dec. 31 and noted that the frequency of the variant “has increased significantly in all regions of England,” with a frequency of 50% or more in all regions of the National Health System.

The Imperial College group examined both epidemiological and genetic data, including 1,904 complete genomes from October and December 5 with a genetic background of 48,128 genomes collected over the same period. Notably, they found a “high correlation” between S gene target failure (SGTF) during COVID-19 PCR testing and variant frequency, meaning that failure of the S gene target could act as a biomarker to measure the variant in the community.

“We see a very clear visual association between SGTF frequency and epidemic growth in nearly all areas … which is reinforced by empirical assessment of area-specific week-on-week growth factors of [variant] and not-[variant] case numbers, ‘wrote Volz and colleagues.

They found a “small, but significant” shift to those under 20 years of age who were more affected by the variant, even after adjusting for various confounding factors. A number of factors could explain this: a general increase in the transmissibility of the variant, younger people are more prone or more symptomatology with the variant.

The group cautioned that while further research is needed, a variant with increased transmissibility indicates that more public health measures may be needed to contain the virus.

“Measures to disengage from society will need to be more stringent than would otherwise be the case. One particular concern is whether it will be possible to maintain control of the handover while schools reopen,” the group wrote.

But there is still no evidence that the variant will withstand vaccine-mediated immunity, or that it is more deadly, except to the extent that hospitals are more overloaded with cases and thus less able to provide high-level care to each patient.