Oxford, England – While most COVID-19 vaccine trial volunteers have no idea whether they are getting the real vaccine or a placebo, for the volunteers participating in a potentially paradigm-shifting new study in the UK, there is no placebo. It’s not a matter of that or they’ve had a chance, but which – or rather, which two.
As CBS News correspondent Charlie D’Agata reports, this is the first COVID-19 vaccine trial of its kind, and scientists say the results could revolutionize the future of vaccine distribution, while also being the most powerful weapon to date. against emerging coronavirus variants.
D’Agata met Reeka Trikha just as she was about to receive her first injection as part of the trial. She had no idea what would be shot in the arm.
“I’ll leave it in the capable hands of the doctors,” she said, taking the plunge.
The scientists behind the Oxford University-led trial are very consciously mixing things up – not just testing one vaccine, but combining doses of two different drugs to see what happens.
More than 800 volunteers aged 50 and over are participating in the trial. Some get a Pfizer “prime” shot followed by one AstraZeneca booster, a second group of AstraZeneca followed by Pfizer, and a third group of participants will receive the same vaccine twice – in the standard way – for comparison.
Shots are taken in different trial groups at breaks of both four and twelve weeks to see what works best.
“With that knowledge, we can have complete confidence that a number of different vaccines can be rolled out and deployed in a population very quickly and very efficiently, without having to worry about inadvertent mixing of the combination,” says Professor Paul Heath, director of the vaccine. Institute at St. George’s University of London and the principal investigator at one of eight trial sites in the UK, told CBS News.
Evidence from the trial could indicate that not only the Pfizer and AstraZeneca vaccines, but possibly any combination of all COVID-19 vaccines could be safe and effective in preventing symptomatic infections. That flexibility could go a long way in alleviating the inevitable supply problems that are already cropping up around the world.
But it could be even better news than that: Heath says that using alternating vaccines between a person’s two doses could actually provide better overall protection against emerging variants of the virus.
“Potentially with a primary boost from different vaccines, the broader response, the broader immune response that follows, will be enough to address, for example, the South African variant,” he said, referring to a virus strain showing some degree of resistance to the current vaccine offer.
As unpredictable as the virus has been, two challenges are certain: Global shortages will get worse and the virus will continue to mutate.
The results of the UK trial may provide the best hope for addressing both issues.
For those who have already had a vaccine, it remains unclear exactly how long the protection will last. If we all end up needing booster shots, the Oxford study will clarify whether we might be better off turning the vaccine off next time.