Guwahati: Preliminary results have shown that a COVID-19 vaccine developed by the University of Oxford appears safe and "trains the immune system."
The trials by Oxford involved 1,077 people and the results show that the vaccine led to them making antibodies and white blood cells that can fight the dreaded virus. Although the early findings are really promising, it is too soon to gauge whether the vaccine can actually defeat the COVID-19 and larger trials are said to be underway.
Meanwhile, the United Kindom, one of the worst-hit countries, has so far ordered 1 crore doses of the vaccine, and thus, the vaccine - called ChAdOx1 nCoV-19 - is being developed at unprecedented speed.
According to scientists, the COVID-19 vaccine is made from a genetically engineered virus that causes the common cold in chimpanzees. The virus has been modified so that it cannot cause infections in people. Also, it has been made to resemble the novel coronavirus by transferring the genetic instructions for the coronavirus's "spike protein" to the vaccine. The immune system can learn how to attack the COVID-19 virus.
Although the vaccine is generally considered "safe", scientists admitted that 70% of people on the trial developed either fever or headache -- problems that can be managed with paracetamol. Prof Sarah Gilbert from Oxford has said that there is still much work to be done before the scientists can confirm if the ChAdOx1 nCoV-19 vaccine will help manage the COVID-19 pandemic, but said "these early results hold promise."
Vaccines provide the human immune system with harmless copies of an antigen, which is a portion of the surface of a bacterium or virus that the immune system recognizes as foreign. A vaccine may also provide a non-active version of a toxin - a poison produced by a bacterium - so that the body can devise a defense against it. Vaccines typically have to follow higher safety standards than other drugs because they are given to millions of healthy people.
It needs mention here that the vaccine testing is a four-stage process. Firstly, preclinical testing is conducted on animals. Then, phase I trials are conducted on a small group of people to check for safety. The Phase II trials are expanded safety trials, and the Phase-III trials are conducted on a large group of people to confirm the efficacy of the vaccine.