NIAID Now | December 08, 2021

COVID-19 Single-Dose Nasal Vaccine Designed for Infants, Children
Candidate Vaccine Against HPIV3 and SARS-CoV-2 

NIAID scientists have developed a candidate COVID-19 vaccine targeted for infants and young children that would require one dose delivered by a nasal spray. They originally had been working on a vaccine to prevent respiratory disease caused by human parainfluenza virus type 3 (HPIV3) in young children. When the COVID-19 pandemic began, they quickly adapted their project to include SARS-CoV-2, the virus that causes COVID-19. A pediatric clinical trial is being planned for a single vaccine that would protect against both viruses.

In a new study published Dec. 7 in PNAS, NIAID’s Ursula Buchholz, Ph.D., Shirin Munir, Ph.D., Cyril Le Nouen, Ph.D., and colleagues in Bethesda, Maryland, and Hamilton, Montana, describe how they used a weakened version of a bovine/human parainfluenza virus (called B/HPIV3) to deliver SARS-CoV-2 spike protein to stimulate immunity against COVID-19. Think of how we use a grocery cart to carry food items to our vehicles. In this case, B/HPIV3 is the cart loaded with protective proteins that train our immune system to protect against SARS-CoV-2 and HPIV3. The vaccine is noteworthy because the nasal delivery creates immunity in the respiratory tract, which is thought to be particularly effective in restricting respiratory virus infection and transmission.

The group developed two versions of the vaccine for SARS-CoV-2 and compared them in hamsters to mimic COVID-19 in people. Candidate vaccine B/HPIV3/S-2P performed the best and was safe and effective at preventing SARS-CoV-2 from spreading in the nose and lungs. (continue)

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