Active ingredient in insect repellent may protect against COVID-19: UK study

An active compound found in insect repellents may provide protection from a strain of coronavirus that causes COVID-19, according to a preliminary study conducted by UK’s defence laboratory.

Scientists at Defence Science and Technology Laboratory (DSTL) said in a statement that Citriodiol, the active ingredient in repellents such as Mosi-guard, had anti-viral properties if mixed with the virus in the liquid phase and on a test surface.

“Mixing a virus suspension with Mosi-guard spray or selected constituent components resulted in a reduction in SARS-CoV-2,” according to the findings.

However, it is unclear whether the spray would make any practical difference beyond frequent hand-washing and the use of alcohol-based hand sanitisers in protecting against the virus.

Citriodiol is derived from the leaves and twigs of Eucalyptus citriodora tree and is marketed as a natural alternative to Deet, another ingredient used in insect repellents.

The military scientists adopted two experimental approaches. The first approach assessed the anti-viral activity of the product when applied directly to the virus as a liquid drop.

In the second method, assessment of the product was done following its application to latex ”synthetic skin”.

The study found that one-minute liquid suspension tests indicated that Mosi-guard has anti-viral activity against SARS-CoV-2 England-2 isolate if mixed with the virus in the liquid phase.

“Additionally, viral studies on latex indicated that Mosi-guard had antiviral activity against SARS-CoV-2 England-2 isolate,” the scientists said in a statement.

The scientists said they are sharing their preliminary findings, which have not been peer-reviewed, in the hope that further research will be carried out.

“This research paper demonstrates preliminary findings on the effectiveness of Citriodiol against COVID-19,” the statement said.

“DSTL is hopeful that the findings in this research can be used as a springboard for other organisations to expand and develop the research, as well as to confirm the findings in this publication,” it said.