One possible explanation is that over-expansion of the thorax and lungs allows for increased alveolar flooding in excess of base line aeration resulting in approximately unaltered ALVs between the two groups. Another explanation is that the inflamed and oedematous areas were aerated less than normal, but because the unaffected see more areas of lung were aerated more than normal (hyperinflation

or emphysema), the overall ALV values remained approximately unaltered. Nevertheless, these ALV profiles provide more detailed knowledge about the influenza-induced respiratory disease development than confined data obtained from a single predefined read out. Moreover, survival and recovery from challenge infection can be included in this set-up and with the opportunity to still measure the development of serum antibody responses

upon challenge infection. Upon necropsy, the relative lung weights (RLWs) of the intranasally immunised ferrets was about 2-fold lower (Mann–Whitney, two-tailed, P < 0.0047) as compared to those of the placebo-treated animals ( Fig. 3), which is in agreement with the absence of pulmonary ground-glass opacities. Usually, more severely affected and inflamed lungs with increased amounts of fluid are heavier compared to normal or less affected lungs. This Palbociclib price translates within the ferret model in influenza research to RLWs ≤ 1.0 associated with non- to minimally affected lungs and RLWs > 1.0 associated with Fossariinae severe pulmonary inflammation with oedema [12], [19] and [20]. In conclusion, the implementation of consecutive CT imaging enables repeated in vivo measurements of lung aeration as parameter to evaluate vaccine efficacy in preclinical protocols. Consecutive day to day imaging overcomes the limitations entailed by necropsy at a predefined time point after infection, and the lung capacity can be repeatedly quantified in real-time. We are grateful to Willem van Aert, Ronald Boom, Cindy van Hagen, Rob van Lavieren from ViroClinics Biosciences B.V., Peter van Run from the Department of Virology Erasmus MC Rotterdam,

and Dennis de Meulder from the Erasmus Laboratory Animal Science Center Rotterdam for their excellent technical assistance and analyses. Conflict of interest: The authors EVK, VT, KS, GvA, LdW, and AO are affiliated with Erasmus MC spin-off company ViroClinics BioSciences B.V. The author JH is affiliated with Karolinska Institutet spin-off company Eurocine Vaccines AB. “
“Despite progressive increases in seasonal influenza vaccine coverage, influenza-related morbidity, mortality, and hospitalization rates remain high and have continued to increase in older adults (≥65 years of age) [1]. Up to 90% of all annual influenza-related deaths occur in the older adults [2], whose aging immune systems respond weakly to vaccines and are less able to combat infection [1], [3], [4] and [5].