New SARS-CoV-2 variant

tl; dr: there is a mutated strain of COVID that seems to spread a lot more quickly. Here is its Wikipedia page.

Last Monday (Dec 14) the UK MP’s were informed of a new strain of COVID-19, named “VUI – 202012/​01”. This strain seems to spread more quickly than other forms of COVID-19, and wikipedia claims that this might be related to the mutated spike protein.

Two days ago (Dec 18) the NERVTAG (an expert panel advising the Chief Medical Officer of the UK, who in turn advises the UK Department of Health and Social Care) meet and release their meeting minutes, stating that:

  • “Growth rate from genomic data: which suggest a growth rate of VUI-202012/​01 that that is 71% (95%CI: 67%-75%) higher than other variants.” [sic]

  • “Studies of correlation between R-values and detection of the variant: which suggest an absolute increase in the R-value of between 0.39 to 0.93.”

amongst other information on this new strain (the meeting minutes are 3 pages only so I encourage people to check them if interested).

Yesterday (Dec 19) Prime Minister Boris Johnson announced a lockdown for London, South East and East of England starting the day after (so today, Sunday), to combat the spread of this new strain.

Today (Dec 20) the European Centre for Disease prevention and Control (ECDC) released a threat assessment brief. The same day multiple countries in Europe (a quick search reveals Germany, France, Belgium, the Netherlands, Italy and Austria, but I possibly have missed others) issue travel restrictions from the United Kingdom and South Africa.

To the best of my ability to interpret the above documents it is too early to make conclusive statements about the impact this strain will have on the COVID-19 pandemic. The threat assessment brief states that “To date, there is no indication of increased infection severity observed related to the variant, but the assessment is challenged by the fact that the majority of cases were reported in people under 60 years old, who are less likely to develop severe symptoms [29].”. This seems like relatively good news—so far the health impact is not noticeably worse. However, the strain is spreading like a wildfire:

Source: the ECDC threat assessment brief. No, I also don’t know why their constant bars are on a logarithmic scale and their exponential growth is on a linear one.

The blue line is the fraction of all reported COVID-19 cases in the UK that are VUI – 20201201 cases. It appears to be growing exponentially, indicating that it spreads more easily than other strains (it is outcompeting them).

As stated above it is not clear what the impact of this strain will be on public health. Some questions that I would love to see discussion on include

  • How likely is it that the spread of this new strain was caused by a few superspreaders, and that most of the above is blown out of proportion?

  • What, uh, does the “71% higher growth rate” mean? Is this different from the R in that is also incorporates the length of the incubation period/​infectious period? Can we infer the reproduction rate R from the growth rate or vice versa?

  • Is there any reason to suspect this new strain might have an impact on vaccination plans? Are the currently approved vaccines (pick a country of choice to decide what this means) possibly better/​worse/​other against this strain?