Assessment of the Efficacy of Commercially Available and Candidate Vaccines against a Pandemic H1N1 2009 Virus

作者：Kobinger Gary P^*; Meunier Isabelle; Patel Ami; Pillet Stephane; Gren Jason; Stebner Shane; Leung Anders; Neufeld James L; Kobasa Darwyn; von Messling Veronika

来源：Journal of Infectious Diseases, 2010, 201(7): 1000-1006.

DOI：10.1086/651171

Background. The emergence and global spread of the pandemic H1N1 2009 influenza virus have raised questions regarding the protective effect of available seasonal vaccines and the efficacy of a newly produced matched vaccine.
Methods. Ferrets were immunized with the 2008-2009 formulations of commercially available live attenuated (FluMist; MedImmune) or split-inactivated (Fluviral; GlaxoSmithKline) vaccines, a commercial swine vaccine (FluSure; Pfizer), or a laboratory-produced matched inactivated whole-virus vaccine (A/Mexico/InDRE4487/2009). Adaptive immune responses were monitored, and the animals were challenged with A/Mexico/InDRE4487/2009 after 5 weeks.
Results. Only animals that received the swine or matched vaccines developed detectable hemagglutination-inhibiting antibodies against the challenge virus, whereas a T cell response was exclusively detected in animals vaccinated with FluMist. After challenge, all animals had high levels of virus replication in the upper respiratory tract. However, preexisting anti-pandemic H1N1 2009 antibodies resulted in reduced clinical signs and improved survival. Surprisingly, FluMist was associated with a slight increase in mortality and greater lung damage, which correlated with early up-regulation of interleukin-10.
Conclusions. The present study demonstrates that a single dose of matched inactivated vaccine confers partial protection against a pandemic H1N1 2009 virus, and it suggests that a higher dose or prime-boost regimen may be required. The consequences of mismatched immunity to influenza merit further investigation.

• 出版日期2010-4-1