Early results of a Phase 1/2 trial of a coronavirus vaccine developed by the University of Oxford and AstraZeneca suggest the vaccine is safe and induces an immune response. More study is needed to know whether the vaccine protects against Covid.
Phase 2 results for one vaccine candidate made by Chinese company CanSino Biologics were also published in the medical journal The Lancet and early results from Phase 1/2 trials of the vaccine made by Pfizer and BioNTech were released in a pre-print paper that has not yet been peer-reviewed.
The Oxford vaccine prompted an antibody response within 28 days and a T-cell response within 14 days, according to the results published Monday. Neutralizing antibodies — so-called because they can neutralize the virus — were detected in most participants after one shot, and in all of them after two.
That’s good news, researchers said. “The immune system has two ways of finding and attacking pathogens — antibody and T cell responses. This vaccine is intended to induce both, so it can attack the virus when it’s circulating in the body, as well as attacking infected cells,” University of Oxford pediatrician Dr. Andrew Pollard, the study’s lead author, said in a statement.
“We hope this means the immune system will remember the virus, so that our vaccine will protect people for an extended period. However, we need more research before we can confirm the vaccine effectively protects against SARS-CoV-2 infection, and for how long any protection lasts.”It’s also not clear how well the vaccine would perform in older people who are more at risk of severe disease from Covid-19.
The vaccine trial included 1,077 people age 18 to 55 with no history of coronavirus infection and took place in five UK hospitals from late April to late May. Participants received the Covid-19 vaccine or a meningitis vaccine.
There were no serious adverse event related to the vaccine; fatigue and headache were the most commonly reported reactions. Other common side effects included pain at the injection site, muscle ache, malaise, chills, feeling feverish and high temperature.
‘There’s a long way to go’
These Phase 1/2 results were promising, researchers said, but large-scale trials are needed to determine whether the vaccine protects against the coronavirus.
“The key elements required to proceed to a Phase 3 trial are all there,” Stephen Evans, a professor of pharmacoepidemiology at the London School of Hygiene and Tropical Medicine, told the Science Media Center in the UK about the Oxford trial.
“The responses measured in the blood and the absence of serious harms indicate there is a possibility of an effective vaccine against Covid-19. It does not yet show that the disease is reduced or prevented, and this will not be easy to show until phase 3 trials have been completed in settings where the SARS Cov-2 virus is circulating at a high rate and people are getting clinical and severe disease.
