A special nose spray might calm your body's overreactions

Some vaccines made with weakened viruses don’t just protect against the specific disease—they might also give your whole immune system a boost that could help protect your brain from damage, unlike other vaccines that only target one part of the virus.

Scientists gave mice a nasal spray vaccine called BPZE1 to help calm their allergic asthma symptoms—like wheezing and lung swelling—and it worked without making their allergy antibodies worse, while also switching their immune system from an allergy mode to a more protective mode.

Giving mice a special nasal spray meant to protect against whooping cough also helps them survive a flu infection better—not by killing the flu virus, but by calming down their overactive immune response, which otherwise causes dangerous lung swelling.

When mice get a special nose spray vaccine called BPZE1, it helps them survive a dangerous bacterial lung infection by calming down their immune system’s overreaction—especially by stopping too many inflammation cells from rushing in and by bringing in peacekeeping immune cells that keep things from getting out of hand.

A live whooping cough vaccine helps mice fight off similar bacteria that cause lung infections — but a common injected vaccine doesn’t, showing live vaccines may work differently.