As many as 23 potential COVID-19 vaccines are in the human trial stage, according to data from the World Health Organization.
"Such side effects have been seen in other vaccines as well and these subside in a few days' time".
The AZD1222 vaccine has been adapted from a common cold virus found in chimpanzees, with spike glycoprotein, a genetic material from the new coronavirus, added to it.
While the study showed there was an immune response generated by the vaccine, scientists cautioned that direct evidence showing whether or not it would prevent or reduce actual novel coronavirus infection has not been documented yet.
The participants were each given one dose and followed for about a month. Ten of them were given a second dose after 28 days.
The results show the desired and expected effects in terms of the immune response and "does not have serious adverse effects seen in the numbers recruited so far", Stephen Evans, professor of pharmacoepidemiology at the London School of Hygiene and Tropical Medicine in the United Kingdom, said.
"The immune responses to the ChAdOx1 nCoV-19 vaccine were measured both in terms of quantity and quality of antibody as well as for T cell responses to the spike protein in a subgroup of individuals", Ms Kampmann said in a statement. While antibodies make up the protein component of the immune system, T cells offer vital cell-mediated immunity, she explained.
The speculations, however, were already answered back by the researchers from Oxford.
Trials showed the jab led to people making antibodies and white blood cells that can fight coronavirus, researchers said. "In addition, we will soon start manufacturing the vaccine in large volumes", he added.
Before a vaccine can be approved for mass production and global distribution, it has to go through three stages, sometimes four, of clinical trials in humans. "What this vaccine does particularly well is trigger both arms of the immune system", he said.
Hill said that larger trials evaluating the vaccine's effectiveness, involving about 10,000 people in the U.K.as well as participants in South Africa and Brazil are still underway.
Hill said Oxford's vaccine is created to reduce disease and transmission. "So that's the subject of future work, and there'll be more publications to come".
The initial success of the vaccine developed by Oxford-AstraZeneca gives positive hope.
AstraZeneca has signed agreements with governments around the world to supply the vaccine, should it gain regulatory approval.
The study found the potential COVID-19 vaccine from Oxford- AstraZeneca helped develop neutralising antibodies in volunteers participated in the trials.
Clinical trials of seven others - some of these situated in China and the U.S. - are also being held.
LONDON-Scientists at Oxford University say their experimental coronavirus vaccine has been shown in an early trial to prompt a protective immune response in hundreds of people who got the shot.
The study also shows that the vaccine candidate did not induce any severe side effects. "The strongest response was noted among those who received two doses of the vaccine", said the University.