The virus had gained a stunning ability to infect people, jumping from one person’s nose to the next. Cases soared this winter, even among vaccinated people.
That is leading scientists to rethink their strategy about the best way to fight future variants, by aiming for a higher level of protection: blocking infections altogether. If they succeed, the next vaccine could be a nasal spray.
The immunology is complex, but the idea is simple. A puff of droplets up people’s nostrils could provoke “mucosal” immunity — a virus-fighting force embedded in the tissue that lines the airways. The localized protection could stanch transmission and help stifle the next variant.
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Some scientists debate whether the goal of blocking transmission and mild infections is too lofty, and even proponents acknowledge the regulatory path could be complicated. The primary goal of vaccination is to protect people from severe sickness, not to prevent every mild case.
But the idea is gaining traction.
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“If we want to change the goal posts, so to speak, and get into really limiting infection and preventing infection, the final bullet point is, we need to change the route of immunization,” [immunology expert Robert] Seder said.