Matt Hancock has said he had wished he had known the coronavirus could spread asymptomatically sooner - despite the government’s advisers saying symptom-free transmission could “not be ruled out” in a document drafted in February.
The health secretary said not having a developed understanding of how the virus spread was his biggest regret in the aftermath of the UK outbreak, which has led to the deaths of 41,788 people and 136,330 hospitalisations.
However government documents drafted in the days after England confirmed its first cases revealed the possibility of asymptomatic spread was among the concerns being considered by the government’s scientific advisers.
Meanwhile medical journals had already published examples of asymptomatic spread of the virus as far back as 5 March as the virus began to infect populations across the globe.
The minister was asked by Philip Schofield on ITV’s This Morning: “What do you regret the most about, since March - so if you changed one thing, what would you have changed?”
“I wish that we’d known earlier how the virus spreads before people have symptoms, because that changes how you manage it,” Mr Hancock responded. “Because at the start we thought it was only when you have symptoms that you can spread it, but actually it’s before and that means things like, if you’re perfectly well, then you need to be more careful - so that’s led to changes in the face mask policy.”
But the potential for such a spread was being considered by the government’s scientific advisory committee Sage as far back as February, with a document comparing the virus to the spread of influenza saying asymptomatic infection could not ruled out.
At the time the UK’s confirmed case number was still in single digits.
“Human-to-human transmission outside China has occurred”, the document, dated 10 February, noted. “Sustained human-to-human transmission outside China cannot be ruled out, but there is as yet no definitive evidence of a sustained outbreak/epidemic elsewhere.”
“Asymptomatic transmission cannot be ruled out and transmission from mildly symptomatic individuals is likely.”
Professor Jurgen Haas, Head of Infection Medicine at the University of Edinburgh told The Independent: “We knew very early on from reports from China that a fair number of transmissions - it was speculated at some point up to 50 per cent - are from asymptomatic or presymptomatic cases.
“In fact, I contacted Health Protection Scotland (HPS) in early February indicating that the guidelines at that time that only symptomatic travellers from China - which at that point was the epicentre for Covid-19 - should be quarantined were insufficient.”
Noting that many but not all virus infections can be asymptomatic, he added: “The many deaths in care homes were not just caused by asymptomatic Covid-19 infections but by insufficient and inadequate government guidelines. We know and we knew that Covid-19 can be positive and spread by (at least some) patients for quite some time.”
While an initial study prepared for Public Health England by Sage in January assessed that available data was “not adequate to provide evidence for major asymptomatic/subclinical transmission," Sage scientists continued to develop plans that would help in the event of asymptomatic spread in early February.
Documents advising the government on the pandemic at the time, which said school closures could be particularly vital if the virus could spread without symptoms, added that contact tracing was “critically important in early cases to gain an understanding of disease dynamics, particularly to answer questions about transmission, including asymptomatic transmission”.
The Department for Health and Social Care has been approached for comment.