A London-based Covid-19 study has found the average time between being exposed to the virus and it being detected is 42 hours – far less than official guidance.
The government’s estimated “incubation period” is between five and six days.
Deputy chief medical officer for England, Professor Jonathan Van-Tam said: “Challenge studies could still prove to be important in the future to speed the development of ‘next-generation’ Covid-19 vaccines and antiviral drugs.
“This data underline just how useful a tool lateral flow tests can be to pick up people when infectious and the importance of wearing a face covering in crowded, enclosed spaces.”
The study, by Open Orphan in conjunction with Imperial College London, the Vaccine Taskforce and Department of Health and Social Care (DHSC), and the Royal Free London NHS Foundation Trust, is the world’s first Covid-19 characterisation study,
While vaccines are still critical in reducing infection numbers, the study found that Covid-19 was most discoverable in the throat at first but was then seen at “significantly” higher levels in the nose – highlighting the benefit of wearing a face mask to limit the spread.
The government last week scrapped the mask mandate, though mask wearing remains a “condition of carriage” on the Tube and London buses.
Global vaccine uptake
The United Arab Emirates currently leads the world in its vaccine uptake, with 93 per cent of the population being fully vaccinated, according to Our World in Data, followed by Portugal with 90 per cent of its population.
Just over 88 per cent of Chile’s population has received at least two doses of a Covid-19 vaccine. While China, which has maintained a tough stance on the virus, has fully vaccinated nearly 85 per cent of its people.
France and Germany have delivered at least two doses to 76.3 per cent and 73.4 per cent of their populations respectively. And 71 per cent of people in the UK have had at least two jabs.
However, just 10 per cent of people in low-income countries have received even one dose, after 10.12bn doses have been administered globally.