Oxford University ChAdOx1 nCoV-19 vaccine trial begins in humans

Researchers at the University of Oxford in the UK have commenced the ChAdOx1 nCoV-19 vaccine trial in healthy human volunteers to test the vaccine candidate’s ability in protecting against the novel coronavirus.

Nearly 1,100 people, aged between 18 and 55 are taking part in the Oxford University coronavirus vaccine trial, of which half of them will be given the ChAdOx1 nCoV-19 vaccine, while the remaining half will be administered with MenACWY, a commonly available meningitis vaccine.

The participants in the coronavirus vaccine trial will not know if they have been given the ChAdOx1 nCoV-19 vaccine candidate until the end of the study. They will be given an E-diary to note down any symptoms developed for seven days after being administered with the vaccine.

The participants will also record if they do not feel well for the following three weeks.

Oxford Uninversity stated: “Following vaccination, participants will attend a series of follow-up visits. During these visits, the team will check participants’ observations, take a blood sample and review the competed E-diary. These blood samples will be used to assess the immune response to the vaccine.

“If participants develop COVID-19 symptoms during the study, they can contact a member of the clinical team, and we will assess them to check whether they have become infected with the virus. If a participant was very unwell, we would call our colleagues in the hospital and ask them to review the volunteer if appropriate.”

Oxford University ChAdOx1 nCoV-19 vaccine trial begins in humans. Image courtesy of fernando zhiminaicela from Pixabay.

The COVID-19 vaccine trial is also expected to help with valuable information on the safety aspects of the coronavirus vaccine candidate and its ability to deliver good immune responses against the virus.

According to Oxford University, its COVID-19 vaccine candidate is based on an adenovirus vaccine vector and the SARS-CoV-2 spike protein, produced at the university. The ChAdOx1 nCoV-19 vaccine has been derived from a virus called ChAdOx1, which is a weakened version of a common cold virus that infects chimpanzees and has been genetically modified so that it is not possible for it to grow in humans.

Oxford University revealed that genetic material was added to the ChAdOx1 construct, which is used for making proteins from the COVID-19 virus (SARS-CoV-2) known as Spike glycoprotein (S). This protein is found usually on the surface of SARS-CoV-2 and plays a key role in the infection pathway of the SARS-CoV-2 virus, said the university.

By using its spike protein to bind to ACE2 receptors on human cells, the SARS-CoV-2 coronavirus gains entry to the cells, thereby causing an infection.

Oxford University is hoping that the ChAdOx1 nCoV-19 vaccine candidate will make the body recognize and develop an immune response to the Spike protein that will help prevent the SARS-CoV-2 virus from gaining entry into the human cells and as a result, preventing the COVID-19 infection.

The university said that vaccines made from the ChAdOx1 virus have been administered to over 320 people so far and have been proved to be safe and well-tolerated. However, they can trigger temporary side effects like a temperature, headache, or sore arm.

The researchers will determine if the ChAdOx1 nCoV-19 vaccine candidate is successful or not by comparing the number of people who get infected with COVID-19 in the coming months from those in the trial.

The university said that to assess the efficacy of the vaccine candidate, statisticians in its team will compare the number of infections in the control group with the number of infections in the vaccinated arm. For this reason, the university says that it is essential for a small number of study participants to develop the COVID-19 infection.

Oxford University said that how quickly the required numbers are reached will be based on the levels of COVID-19 transmission in the community. In case of the transmission continuing to be high, the university said that it can get sufficient data in two months to see if the ChAdOx1 nCoV-19 vaccine candidate works. However, if the COVID-19 transmission levels fall, then it could take up to six months.