The question of whether pre-existing influenza immunity generated by prior viral or vaccine exposure could hamper the production of broadly neutralizing antibodies may have been answered by a recent study.
Scientists were previously unsure if a universal flu vaccine could only be administered in very young children. It was thought that perhaps only people without previous flu or vaccine exposure could achieve the full immune system effect. A study conducted by the Vaccine Research Center at the National Institute of Allergy and Infectious Disease may show that such a vaccine could be effective no matter what the previous level of flu or vaccine exposure, Science Codex reports.
The mouse and ferret study showed that broadly neutralizing influenza antibodies were elicited by a prime-boost vaccine regimen, even after the animals established prior immunity to influenza. The vaccine regimen consisted of a DNA vaccine prime and an inactivated seasonal vaccine boost.
The study also showed that the broadly neutralizing antibodies could be produced in the animals regardless of whether the pre-existing immunity was the result of flu virus exposure or following the vaccination with a standard seasonal flu vaccine, according to Science Codex.
Ferrets that were inoculated with the prime-boost regimen experienced protection against challenges with strains of unmatched influenza virus. If the same effect is found in humans, it might be possible to effectively administer long-lasting flu protecting vaccines to people of all ages.
Multiple clinical trials to test first generation universal flu vaccines are underway or planned at the VRC, Science Codex reports.