The vaccine did not prompt any serious side effects and elicited antibody and T-cell immune responses
AstraZeneca's experimental COVID-19 vaccine was safe and produced an immune response in early-stage clinical trials in healthy volunteers, data showed on Monday.
The vaccine, called AZD1222 and under development by AstraZeneca and scientists at Britain's Oxford University, did not prompt any serious side effects and elicited antibody and T-cell immune responses, according to trial results published in The Lancet medical journal.
"We hope this means the immune system will remember the virus, so that our vaccine will protect people for an extended period," study lead author Andrew Pollard of the University of Oxford said.
Frequently Asked Questions
A vaccine works by mimicking a natural infection. A vaccine not only induces immune response to protect people from any future COVID-19 infection, but also helps quickly build herd immunity to put an end to the pandemic. Herd immunity occurs when a sufficient percentage of a population becomes immune to a disease, making the spread of disease from person to person unlikely. The good news is that SARS-CoV-2 virus has been fairly stable, which increases the viability of a vaccine.
There are broadly four types of vaccine — one, a vaccine based on the whole virus (this could be either inactivated, or an attenuated [weakened] virus vaccine); two, a non-replicating viral vector vaccine that uses a benign virus as vector that carries the antigen of SARS-CoV; three, nucleic-acid vaccines that have genetic material like DNA and RNA of antigens like spike protein given to a person, helping human cells decode genetic material and produce the vaccine; and four, protein subunit vaccine wherein the recombinant proteins of SARS-COV-2 along with an adjuvant (booster) is given as a vaccine.
Vaccine development is a long, complex process. Unlike drugs that are given to people with a diseased, vaccines are given to healthy people and also vulnerable sections such as children, pregnant women and the elderly. So rigorous tests are compulsory. History says that the fastest time it took to develop a vaccine is five years, but it usually takes double or sometimes triple that time.
"However, we need more research before we can confirm the vaccine effectively protects against SARS-CoV-2 (COVID-19) infection, and for how long any protection lasts," he said.
AstraZeneca's is among the leading vaccine candidates against a pandemic that has claimed more than 600,000 lives, alongside others in mid and late-stage trials.
These include shots being developed by China's Sinovac Biotech, another from state-owned Chinese firm Sinopharm, and one from the U.S. biotech firm Moderna.
AstraZeneca has signed agreements with governments around the world to supply the vaccine should it prove effective and gain regulatory approval. The company has said it will not seek to profit from the vaccine during the pandemic.Researchers said the vaccine caused minor side effects more frequently than a control group, but some of these could be reduced by taking paracetamol, with no serious adverse events from the vaccine.