Single rapid Covid test 'as effective as quarantine'

A single rapid antigen test for Covid-19 upon arrival is as effective as 10 days’ self-isolation in reducing imported cases of Covid-19, the authors of a new study commissioned by a coalition of aviation industry stakeholders have claimed.

Based on the prevalence of Covid-19 in the UK and overseas, and accounting for quarantine compliance, Oxera and Edge Health say their findings suggest a single test would be appropriate for arrivals from countries categorised medium-risk as a consequence of either their Covid caseload or vaccination rate.

These countries, Oxera and Edge believe, could be designated "amber" if the UK government was to press ahead with a traffic light system to categorise risk when international travel resumes.

The research partners say many of the quick and inexpensive antigen tests on the market, were they to be deployed at the border, offer more effective screening than mandatory quarantine when taking compliance into consideration.

Oxera and Edge were commissioned last year by British Airways owner IAG, Virgin Atlantic, Heathrow airport, Manchester Airports Group and Iata to investigate whether the government’s own evidence base had underestimated the effectiveness of a single antigen test on arrival.

According to the government’s Scientific Advisory Group for Emergencies (Sage), rapid testing on arrival would only screen 11% of infectious travellers.

Oxera and Edge’s latest findings have been submitted to the government’s Global Travel Taskforce ahead of its 12 April report on how international travel can be reinstated safely and robustly.

Additionally, the study suggests a two-test strategy could be used to restart travel to and from higher-risk, or "red", countries; this would involve an antigen test taken up to 72 hours prior to departure, and three days’ quarantine upon arrival with a PCR test requirement.

This, Oxera and Edge assert, would be equally as effective as a double PCR test requirement, and would also ensure the government is able to track and sequence each strain of Covid-19 entering the UK.

Antigen testing for Covid is considerably quicker and cheaper than PCR testing, which requires laboratory analysis, and airports and airlines believe antigen testing could be more easily integrated into the passenger journey. However, there remains some debate as to which form of testing offers greater accuracy, or an acceptable trade off between accuracy and speed.