Safety and immunogenicity of a quadrivalent influenza vaccine in adults 65 y of age and older

ABSTRACT

Frequent mismatches between the predominant circulating B strain lineage and the B strain lineage in trivalent influenza vaccines have resulted in missed opportunities to prevent influenza illness. Quadrivalent influenza vaccines containing B strains from each of the 2 lineages have been developed for improved prevention of influenza B infections. Here, we describe the results of a phase III, randomized, double-blind, active-controlled, multicenter trial examining the safety and immunogenicity of a split-virion inactivated quadrivalent influenza vaccine (IIV4) in 675 adults ≥ 65 y of age (NCT01218646). Participants were randomly assigned 1:1:1 to receive a single intramuscular injection with the investigational IIV4, or one of 2 split-virion trivalent inactivated influenza vaccines (IIV3s): a licensed IIV3 containing a B Victoria-lineage strain or an investigational IIV3 containing a B Yamagata-lineage strain. Post-vaccination (day 21) hemagglutinin inhibition titers to all strains induced by IIV4 were statistically non-inferior to those induced by the 2 IIV3s. In addition, for each B strain, rates of seroconversion in the IIV4 group were superior to those induced by the comparator IIV3 not containing that B strain. For all vaccines, the most common solicited reaction was injection-site pain, and most reactions were mild to moderate in intensity and transient. Overall safety profiles were similar between IIV4 and the IIV3s, and no vaccine-related serious adverse events were reported. These results confirm that in adults ≥ 65 y of age, IIV4 was well tolerated and immunogenic against the additional B lineage strain without compromising the immunogenicity of the other 3 vaccine strains.

KEYWORDS:

• Influenza
• vaccine
• quadrivalent influenza vaccine
• elderly
• immunogenicity
• safety

Abbreviations

AE	=	adverse event
CI	=	confidence interval
GMT	=	geometric mean titer
HAI	=	hemagglutination inhibition
IIV3	=	trivalent split-virion inactivated influenza vaccine
IIV3–1	=	licensed IIV3 containing a B strain of the Victoria lineage
IIV3–2	=	investigational IIV3 containing a B strain of the Yamagata lineage
IIV4	=	quadrivalent split-virion inactivated influenza vaccine

Disclosure of potential conflicts of interest

D.P.G., C.A.R., and M.D.D. were employees of Sanofi Pasteur during the period of this study. H.K.T has received research support from Sanofi Pasteur, Gilead, and MedImmune and serves as an advisor for Seqirus and VaxInnate.

Acknowledgment

Medical writing assistance in the preparation of this manuscript was provided by Dr. Phillip Leventhal of 4Clinics (Paris, France).

Funding

The study was funded by Sanofi Pasteur. This study funder, Sanofi Pasteur, contributed to the study design, data collection, analysis and interpretation, review of the manuscript, and decision to publish.