According to the World Health Organization, as of July 14, 163 Covid-19 vaccines were being developed around the world, and 23 of them had started clinical trials involving humans.
Vaccine trials usually undergo three rounds of testing: Phase 1, Phase 2 and Phase 3. The first two trials are typically smaller ones, testing mostly for vaccine safety and biological activity, requiring from 50 to hundreds of volunteers respectively. Due to their smaller size, it's relatively easy for pharmaceutical companies to run these studies in their home countries.
Comparatively, Phase 3 trials are a lot more difficult, requiring thousands of volunteers to gauge whether the vaccine works in the real world.
From the many reports I culled, it appears there are three that have reached or almost reaching Phase 3 – the last scientific stage before approval to be marketed.
The first is conducted by UK's University of Oxford in partnership with pharmaceutical company AstraZeneca and which has officially launched a Phase 3 trial involving 50,000 volunteers in the UK, the US, South Africa, Brazil and India.
The second is by Chinese biotech company Sinovac – its CoronaVac trial vaccine uses inactivated virus cells to stimulate an immune response in patients. Tests will begin next Monday in Brazil with 9,000 volunteers, according to CNN – although I’m sure there will be other countries including even China being involved too.
The third developed by US company Moderna and the US National Institutes of Health is expected to enter Phase 3 clinical trials on July 27, and hope to test the vaccine on 30,000 people, including those whose circumstances put them at high-risk of getting infected with the coronavirus. The test sites were not identified – but I suspect the US will be one of them since they’ll want to be able to test the efficacy of the vaccine in a country that has ongoing infections.
Four other companies are also not too far away – US companies, Inovio and Pfizer (partnering with German biotech company BioNTech) as well as China-based companies CanSino and Sinopharm, are all gearing up for their own Phase 3 trials in the coming months.
As the world struggles with Covid-19, the above developments offer real hope.
No comments:
Post a Comment