A Covid variant first identified in India have spread in parts of the UK has threatened to derail Britain’s plans for a return to normalcy. The government is accused of recklessness for allowing the last relief from the closure. So why did it take the risk?
Last Thursday, 39 of the country’s leading scientists and health experts met – via video conference – to discuss the growing situation.
At the Sage meeting, a paper was presented by the government’s modelling committee that was read with concern.
There was, according to the document, a ‘realistic possibility that the Indian variant was 50% more transmissible than the British variant responsible for the deadly winter wave.
If that were the case, the modellers said, there is the potential for a summer wave that would be even worse. It could not have been more worrying.
One of those present, Sir Jeremy Farrar, said they were facing the “most difficult policy decision” of the pandemic – but a reasonable decision that takes the context into account.
If you dig under the headings, a more complex picture emerges than the 50% figure that grabbed the headlines. The term “realistic possibility” is actually a defined phrase, one of several on a sliding scale used by these committees.
This means there is basically a 50:50 chance that the modellers seemed to find the variant as much as 50% more contagious.
Along with the modelling presented Thursday, several other pieces of evidence were looked at. Public Health England (PHE) has collected data on what happened on the ground as part of the testing and detection program. This called into question the 50% figure.
A number of things the analysts did not contribute.
Some data on ‘secondary attack rates’ – the chance that an infected person could transmit the virus to someone – suggests that the variant may be much less contagious than feared.
And it does not seem to be behaving the same way in every region. A significant group was found in London, but it did not rise at the same rate as in Bolton.
The degree of extra portability makes a big difference. A variant that is 20% more transmissible has a much smaller impact on hospital cases.
Indeed, some people believe that these models are too pessimistic. They believe that the vaccination program will halt the increase in infections or at least limit the incidence of serious illnesses more than the modellers outlined.