The first ever Human Infection study, also known as human challenge study, found that people who get infected with COVID-19 start to experience symptoms of the disease two days after contracting the viral infection. The study was conducted by Imperial College London in collaboration with the Vaccine Taskforce and Department of Health and Social Care (DHSC), hVIVO (part of Open Orphan plc.), and the Royal Free London NHS Foundation Trust.
A group of researchers conducted the study on healthy volunteers and infected them with the virus. They monitored them over the time to see the changes in the body from the encounter of the virus and getting the infection to development and onset of symptoms. It is the first of its kind study which identifies the infection from first day to elimination.
It was found that the infection starts from throat and reaches its peak in five days. This indicated that the most efficient way to prevent the virus from spreading is by covering the mouth and nose with a medical mask. The team of researchers also found that Lateral Flow Tests (LFTs) is the effective way to check whether the person infected with the virus is able to transmit the infection to other people.
“Our study reveals some interesting clinical insights, particularly around the short incubation period of the virus, extremely high viral shedding from the nose, as well as the utility of lateral flow tests, with potential implications for public health,” said Professor Christopher Chiu, from the Department of Infectious Disease and the Institute of Infection at Imperial College London. Chiu is also the Chief Investigator on the trial.
The trail was done on 36 healthy unvaccinated participants who never encountered the virus in past. The age of the participants was between 18 years and30 years. Out of the 36 participants, only 18 participants got infected with the coronavirus and 16 participants developed mild-to-moderate cold-like symptoms, including a stuffy or runny nose, sneezing, and a sore throat. While none of the participants experienced serious infection, 13reported the loss of sense of smell which came back within 90 days. However, those who didn’t experience any change in their lungs, or any serious adverse events. All participants will be followed up for 12 months after leaving the clinical facility to monitor for any potential long-term effects.
The team of researchers apart from Chiu included Jonathan Van-Tam, Deputy Chief Medical Officer for England; Peter Openshaw, Experimental Medicine, Imperial College London; Dr Andrew Catchpole, Chief Scientific Officer at hVIVO and Dr Michael Jacobs, consultant in infectious diseases at the Royal Free London.