Are nasal sprays the answer to stopping Covid transmission?

With the virus rampant despite jabs, trials are underway to create intranasal vaccines to block infections from the body

The roaring success of Covid vaccines - in countries able to obtain them - has led to deaths and severe disease from the infection plummeting even as the virus evolved to sidestep immunity and rip through populations more swiftly.

But while the rapid development of Covid shots ranks as the finest achievement of the pandemic, scientists are not done yet. In a small number of labs around the world, teams are taking on a problem that cannot be ignored: that the virus remains rampant in the face of mass immunity.