COVID-19 is a disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). SARS-CoV-2 was first detected in the city of Wuhan, China, in December 2019, after a cluster of patients with pneumonia of unknown cause were reported to the World Health Organization (WHO).
The outbreak was declared a public health emergency of international concern on 30th January 2020, and the disease caused by SARS-CoV-2 was officially named COVID-19 on 11th February 2020. After assessing the outbreak and following transmission of the virus in many other countries worldwide, on 11th March 2020, the WHO declared COVID-19 a pandemic.
A team in Oxford led by Prof. Sarah Gilbert, Prof. Andrew Pollard, Prof. Teresa Lambe, Dr. Sandy Douglas, and Prof. Adrian Hill started work designing a vaccine on Saturday 10th January 2020.
A chimpanzee adenovirus vaccine vector (ChAdOx1), developed at Oxford’s Jenner Institute, was chosen as the most suitable vaccine technology for a SARS-CoV-2 vaccine as it can generate a strong immune response from one dose and it is not a replicating virus, so it cannot cause an ongoing infection in the vaccinated individual. This also makes it safer to give to children, the elderly, and anyone with a pre-existing condition such as diabetes. ( source: Oxford Vaccine Group, March 2020 )
The New York Times reported that six rhesus macaque monkeys were inoculated with the Oxford vaccine in March at the National Institutes of Health’s Rocky Mountain Laboratory in Montana. The monkeys were then exposed to “heavy quantities” of the coronavirus. Such exposure had “consistently sickened other monkeys in the lab”, “But more than 28 days later, all six were healthy,” Vincent Munster, the researcher who conducted the test, told The New York Times. (Source: The Week, April 2020)
The phase I trial in healthy adult volunteers began in April. More than 1,000 immunizations were completed. The next study enrolled up to 10,260 adults and children and involved a number of partner institutions across the country.
The phase II part of the study involved expanding the age range of people the vaccine is assessed in, to include a small number of older adults and children:
• Aged 56-69
• Aged over 70
• Aged between 5-12 years – For these groups, researchers assessed the immune response to the vaccine in people of different ages, to find out if there is variation in how well the immune system responds in older people or children.
On June 13, 2020, AstraZeneca announced that it has reached an agreement with Europe’s Inclusive Vaccines Alliance (IVA), spearheaded by Germany, France, Italy, and the Netherlands, to supply up to 400 million doses of the University of Oxford’s COVID-19 vaccine, with deliveries starting by the end of September.
Trials involving 1,077 people showed the injection led to them making antibodies and T-cells that can fight coronavirus. Neutralizing antibodies can disable the coronavirus.T-cells, a type of white blood cell, help co-ordinate the immune system, and are able to spot which of the body’s cells have been infected and destroy them.
Is it SAFE?
Yes, but there are side-effects.
There were no dangerous side-effects from taking the vaccine, however, around 17% had a fever and more than six-in-10 patients had a headache.
The researchers said this could be managed with paracetamol.
Prof Sarah Gilbert, from the University of Oxford, UK, says: “There is still much work to be done before we can confirm if our vaccine will help manage the Covid-19 pandemic, but these early results hold promise.” (Source: BBC News )
However, the trial has also been expanded to other countries because levels of coronavirus are low in the UK, making it hard to know if the vaccine is effective.
There will be a large trial involving 30,000 people in the US as well as 2,000 in South Africa and 5,000 in Brazil in the months of August and September.