The pandemic’s biggest tests still lie ahead

The pandemic’s biggest tests still lie ahead

Further lockdowns are unavoidable as vaccines are rolled out

The darkest hour, it is said, is always before the dawn. Just when vaccines had brought hope of a gradual loosening of restrictions and return to some kind of normality within months, the emergence of at least two more contagious variants of coronavirus means many populations instead face tighter lockdowns — with all the human and economic damage they bring. Pressures on healthcare systems, and deaths, may exceed those in the bleakest days of the first wave nine months ago. The first part of this year is set to look very different from what was expected even a few weeks ago.

Scientists had always known the virus would mutate. What they did not expect were mutations that were so extensive, or brought such rapid and sizeable changes in impact. The variant ripping through much of the UK — and already found in 25 countries — contains a striking 17 changes in its genomic code that might alter its behaviour. That helped it to supplant its predecessors and spread rapidly even during England’s November national lockdown. A variant found in South Africa has three meaningful changes to its spike protein that also help it to spread much more quickly — and produce a higher viral “load” among victims.

For now, the variants do not seem to have higher mortality rates — though, arithmetically, higher transmission rates left unchecked will lead to more deaths. Neither variant is thought to be more resistant to existing vaccines, though scientists worry more about the South African strain. The creator of the BioNTech/Pfizer vaccine has said the jab can be modified to fight mutant strains within six weeks. But even that would cause crucial delays.