Any prime-boost mix of injected or spray flu vaccine shields toddlers
Research funded by NIH shows protection for children younger than 3 years is the same regardless of whether two doses of flu vaccine are injected by needle, inhaled through a nasal spray or provided through one dose of each in any order.
Balintfy: Influenza vaccinations for young children are provided in a two-dose, prime-boost combination. The first vaccine dose is designed to prime the immune system to produce a favorable antibody response; and the second vaccine dose is the "boost" designed to spur an immune response. Currently there are two types of flu vaccines approved as safe and effective for children: what's called a trivalent, inactivated vaccine and a live, attenuated influenza virus vaccine.
Fauci: The inactivated is an injection and the attenuated is a nasal spray.
Balintfy: Dr. Anthony Fauci, an institute director at NIH says, sometimes when a child comes back for the boost, matching the vaccine could be a logistical challenge.
Fauci: Sometimes when children go back it’s difficult to match them with exactly the same one that they had.
Balintfy: He explains that one goal of a recent NIH-funded study involving four groups of children was to determine whether giving two different types of vaccines works as well as giving two of the same.
Fauci: And what this study shows is that the inactivated vs. the attenuated, it doesn’t matter what order you give them in or how you give them — you could go get an inactivated and then an attenuated or vice versa and the response is still fine — so that takes the pressure off from a logistics standpoint.
Balintfy: Dr. Fauci adds that the study also has an interesting scientific message.
Fauci: The other thing that was important is that they showed something which was generally suspected all along, that the live attenuated is a little bit better than the inactivated in the sense that it induces what we call T-cell responses which might give an additional degree of protection against influenza.
Balintfy: Stimulating broad T-cell responses may be important for protection against many diverse flu strains. Researchers point out that in contrast to currently used flu vaccines – which must be given annually because circulating flu viruses change from season to season – a vaccine capable of eliciting broad T-cell responses could potentially provide decades-long protection against many or all flu strains.
Fauci: So you have a practical message that you can mix and match, you can give one and then the other, both it doesn't matter; you then have an interesting thing for reflection in the future that the live attenuated gives a much better t-cell response.
Balintfy: Researchers add that this trial suggests the best regimen for kids younger than 24 months may be an inactivated or injected vaccine, followed by an attenuated or spray vaccine. And Dr. Fauci reminds that severe complications from seasonal influenza can be devastating to young children. The single best way to prevent the flu is to get a flu vaccine each season. For more information on influenza and this study, visit www.niaid.nih.gov. This is Joe Balintfy, National Institutes of Health, Bethesda, Maryland.
About This Audio Report
Reporter: Joe Balintfy
Sound Bite: Dr. Anthony Fauci
Topic: flu, influenza, vaccine, vaccine dose, immune system, inactivated, attenuated