AstraZeneca, a British Swedish company in collaboration with the University of Oxford has developed a COVID-19 vaccine that has successfully induced an immune response in its early trials. The clinical trials involved 1077 people who developed T-cells and antibodies that can fight coronavirus. The findings from the trials are very promising but the scientists are still trying to find if it really offers protection and for this, the larger trials are underway.
How does it work? The vaccine is called ChAdOx1 nCoV-19 and it is being developed at unique speed. A genetically engineered virus that induces common cold in Chimpanzees is being used for the development of this vaccine. Scientists heavily modified it so it looks more like coronavirus and not cause infections in people. They transferred the genetic instructions from COVID-19’s spike protein, which is a very important tool coronavirus uses to enter into our cells, to the vaccine under development. Due to this vaccine, the body can learn how to attack coronavirus if the body gets infected.
What are T-cells and Antibodies? A lot of focus is being directed towards antibodies when talking about coronavirus vaccines, but antibodies are only a part of our body’s immune system. They are small proteins that stick on the surface of viruses and are made by the immune system. Moreover, T-cell is a type of white blood cell which can identify the cells infected and destroy them and also co-ordinates the immune system. Almost all the vaccines create a response from a T-cell and an antibody.
Antibody levels peaked after 28 days and the level of T-cells peaked 14 days after vaccination. The study has not been run that long to identify how long will the t-cells and antibodies last. Professor Andrew Pollard who is a part of Oxford’s research group believes that the results are extremely promising and that his team is very pleased as the results produced both antibodies and T-cells. He said that everyone wants to know if the vaccine will work and if it offers protection but he believes that only time will answer that question.
According to the study, 90% of the people who were vaccinated developed antibodies able to neutralize the virus after one dose but only 10 of them required two doses to produce the antibodies capable of neutralizing. Dr. Pollard further added that the doses required to assure protection are not known but the second dose can be used to maximize response.
Is the vaccine safe? Yes, but like nearly all other vaccines it develops some side effects. However, no dangerous side effects were observed in patients, only headache or fever was developed in nearly 70% of the people vaccinated. The researchers added that these side effects can be easily managed by giving paracetamol to the patient. University of Oxford’s Professor Sarah Gilbert working on the vaccine said there’s a lot of work still to be done before it can be confirmed if this vaccine will be able to help manage covid19, but these results show promise.
The main purpose of the study is to make sure that the vaccine is safe for the people. However, the study is not able to ensure if the vaccine can lessen the symptoms of covid19 or prevent people from getting ill. The next phase of the trials will include more than 10,000 people in the UK. The trials are also expanded to other countries because the number of people infected in the UK is low which will make it hard to check the effectiveness of the COVID-19 vaccine.
A large trial of this vaccine will be conducted involving 2000 people in South Africa, 5000 in Brazil, and 30,000 people in the US. There are some calls for ‘challenge trials’ to be held in which vaccinated people may be infected with coronavirus deliberately. However, ethical concerns won’t allow this because there is no other treatment of the coronavirus.
There is a possibility that this COVID-19 vaccine will be proven effective before the end of 2020 but it will only be made available to health workers and people who are at greater risk of the virus due to age or medical conditions. However, widespread vaccinations will be available at the earliest by the start of next year if everything goes ok.