Nasal vaccines may be the best way to prevent infections long term, because they provide protection exactly where it is needed to fend off the virus: the mucosal linings of the airways, where the coronavirus first lands.

Bharat Biotech is among the world’s leading vaccine manufacturers. Its best known product, Covaxin, is authorized to prevent Covid in India and many other countries. But its experimental nasal vaccine may prove to be the real game changer.

Immunizing entire populations with a nasal or oral vaccine would be faster in the middle of a surge than injections, which require skill and time to administer. A nasal vaccine is likely to be more palatable to many (including children) than painful shots, and would circumvent shortages of needles, syringes and other materials.