Can two different doses of COVID-19 vaccine be combined and given?
Such a thing is likely to be safe and effective, but researchers are still gathering data to be sure.
“Vaccines authorized worldwide for COVID-19 have been developed to stimulate our immune system and to produce antibodies against the virus, although the way they do this varies,” he said. Kate O’Brien, director of the vaccine department at the World Health Organization. “Based on the basic principles of how vaccines work, we think their combination should work,” said Ms O’Brien.
Scientists at Oxford University in Britain are testing a combination of two doses of COVID-19 vaccines produced by AstraZeneca, Moderna, Novavax and Pfizer-BioNTech. Smaller clinical trials are currently being conducted in Spain and Germany. “We just have to get data on each of these vaccine combinations,” said Ms O’Brien.
The data provided so far suggest that one dose of AstraZeneca vaccine followed by another dose of Pfizer is safe and effective. This combination however seems to come with higher chances of temporary side effects like body aches and fever.
The reason may be that mixing and combining different types of vaccines can often produce a stronger immune response, says Lawrence Young, a virologist at Warwick University in Britain. In some countries, health officials have already suggested combining vaccines under certain circumstances.
After the AstraZeneca vaccine was found to be associated with a rare blood clot, several European countries, including Germany and France, recommended that people who received the vaccine as a first dose receive the Pfizer or Modern vaccine as a second dose. . On Thursday, Canada made the same recommendation.
Some countries like Britain suggest that people aim to get the same vaccine in both doses if possible. If they take the AstraZeneca vaccine as their first dose, people are advised to get another vaccine in the second dose only if they have a history of blood clots or other illnesses that may put them at greater risk. high for blood clotting.