These clinical trials are still in a preliminary phase (phase 1/2 and phase 2), and their effectiveness will have to be established in a phase 3 trial, on a larger number of participants, before considering their large-scale commercialization.
Despite everything, these results were eagerly awaited: many researchers and laboratories around the world are racing against time to find a safe and effective vaccine against Covid-19.
Both vaccines are based on a modified adenovirus, which does not replicate, which makes them safer, especially for fragile patients. Neither trial recorded any serious adverse events. The most observed side effects were fever, fatigue and pain at the injection site.
They said immune responses “may be even stronger after a second dose,” according to a trial in a subgroup of 10 participants. The British government has already ordered 100 million doses of this potential vaccine.
“If our vaccine works, it is a promising option because it can be easily produced on a large scale,” said Sarah Gilbert, a researcher at Oxford University.