Elsevier

Vaccine

Volume 20, Issues 3–4, 12 November 2001, Pages 505-515
Vaccine

A novel liposomal influenza vaccine (INFLUSOME-VAC) containing hemagglutinin–neuraminidase and IL-2 or GM-CSF induces protective anti-neuraminidase antibodies cross-reacting with a wide spectrum of influenza A viral strains

https://doi.org/10.1016/S0264-410X(01)00326-7Get rights and content

Abstract

A liposomal influenza vaccine (INFLUSOME-VAC) was developed with the objective of overcoming the major drawbacks of the currently used influenza vaccines: their relatively low efficacy in certain high-risk groups (the elderly, infants, the immunosuppressed) and the need for annual immunization. INFLUSOME-VAC consists of liposomes containing the viral surface proteins hemagglutinin (HA) and neuraminidase (NA) derived from various influenza strains and IL-2 or GM-CSF, as an adjuvant. Vaccination of mice showed that, whereas conventional vaccines induced a low- and short-term response against HA and very low or no anti-NA response, INFLUSOME-VAC produced high titers of both anti-HA and anti-NA antibodies (Abs) in young and old mice that persisted for at least 6 months. Moreover, the anti-NA Abs efficiently cross-reacted with several N2 viral subtypes spanning 20 years, and such vaccines afforded partial protection against heterosubtypic viral infection.

Introduction

Resistance to influenza virus infection is primarily associated with the humoral response to the major viral surface glycoproteins, hemagglutinin (HA) and neuraminidase (NA) [1], [2], [3], [4], [5]. Anti-HA antibodies (Abs) can effectively prevent viral infection by blocking virus attachment to epithelial cells and its subsequent penetration into the cytosol. Anti-NA Abs, on the other hand, may be less efficient in preventing the primary infection, but such Abs can significantly reduce viral spreading and morbidity by inhibiting virus release from already infected cells, thereby reducing the possibility of infecting new cells [1], [2], [5].

The commonly used influenza vaccines to date consist of inactivated whole virions, split virions (subvirion vaccines) or of HA+NA (HN) (subunit, or surface antigen vaccines), which are quite efficacious (60–90%) in healthy young adults. However, such vaccines are considerably less effective (≤50%) in the elderly, in infants, in patients with certain chronic diseases, and in immunodeficient patients [1], [4], [5], [6], [7], [8], [9], and the duration of protection is relatively short (<1 year) [1], [5]. These vaccines induce high titers of Abs against HA and low levels of Abs against NA, probably because of (a) the low content of NA in the vaccines [10]; (b) the negative influence of prior experience with HA [11], [12] and/or (c) the relatively lower immunogenicity of NA as compared with that of HA. Moreover, the current vaccines afford protection only against a narrow range of viral strains, namely, those included in the vaccine [1], [5]. In view of the vast heterogeneity of the influenza viruses (the old and the recently arising strains), and the frequent alteration in the antigenic make-up (antigenic drift) of the virus, annual vaccination against the circulating strains is highly recommended, particularly for the high-risk groups [5]. New, improved vaccines are therefore needed for (a) reducing morbidity and mortality among the high-risk groups and (b) providing long-term protection against a wider range of viral subtypes, thereby reducing the need for frequent immunization.

Since NA appears to be less antigenically variable than HA [13], vaccines capable of eliciting high levels of Abs to NA, in addition to a strong anti-HA response, may fulfill the two above-mentioned requirements. Recently, we reported on novel influenza vaccines comprising liposome-encapsulated HA+NA and IL-2 or GM-CSF (as vaccine adjuvants [14], [15]). In mice, the liposomal vaccines induced much faster, stronger and longer-lasting humoral and cellular responses, as well as protective immunity, as compared with those evoked by the standard subunit vaccines. In the present study, we demonstrate that our liposomal vaccines also elicit a high titer of anti-NA Abs, and such Abs efficiently cross-react with various influenza A viral subtypes (H3N2) that have emerged over a period of 20 years.

Section snippets

Mice

Specific pathogen-free (SPF) female BALB/c mice, aged 2 or 18 months, were used. Animals were maintained under SPF conditions.

Influenza viruses/antigens

Influenza viruses were obtained from allantoic fluid as described elsewhere [14]. Split-viron and subunit preparations were kindly provided by Dr. Palache, B.V. Solvay Duphar, Weesp, The Netherlands, and by Drs. Glück and Zurbriggen, the Swiss Serum and Vaccine Institute, Bern, Switzerland. The split virus preparations contained 50–60% HA and 25–30% NA/NP (w/w) of total

The anti-HA/NA response following vaccination with free/liposomal antigen co-administered with free/liposomal IL-2 or GM-CSF

Various preparations of non-liposomal and liposomal vaccines were compared (Table 1). Mice were immunized with subunit or split virus preparations derived from influenza A/Shangdong/9/93 (H3N2) given as free antigen (F-HN) or liposome entrapped (Lip-HN), alone and with free/liposomal cytokine. Sera were tested on days 40, 50 and 180 for specific anti-HA Abs (by HI), for anti-NA Abs (by NI), and for total anti-HA/HN Igs (by ELISA).

As shown in Table 1, experiment 1, a low anti-HA Ab titer was

Discussion

Due to the continuous variation in the antigenic make-up of the influenza viruses (antigenic drift), annual vaccination is highly recommended for high-risk groups [1], [4], [5], [6], [7], [8], [9]. In addition to the relatively low efficacy of the currently used vaccines in certain high-risk groups, such vaccines afford poor protection against viral strains that do not match those included in the vaccine. Therefore, more potent influenza vaccines are needed, especially for the high-risk groups.

Acknowledgements

Supported by research grants from the I. Horowitz Foundation and the Israel Science Foundation.

References (46)

  • T. Deroo et al.

    Recombinant neuraminidase vaccine protects against lethal influenza

    Vaccine

    (1996)
  • A.S. Monto et al.

    Effect of neuraminidase antibody on Hong Kong influenza

    Lancet

    (1973)
  • G. Gregoriadis et al.

    Liposomes as immunological adjuvants and vaccine carriers

    J. Control. Release

    (1996)
  • G. Gregoriadis et al.

    Vaccine entrapment in liposomes

    Methods

    (1999)
  • M. Cao et al.

    Enhancement of the protective effect of inactivated influenza virus vaccine by cytokines

    Vaccine

    (1992)
  • Murphy BR, Webster RG. Orthomyxoviruses. In: Fields BN, Knipe DM, Howley PM, Chanock RM, Melnick JL, Monath TP, Roizman...
  • Lamb RA, Krug RM. Orthomyxoviridae: the viruses and their replication. In: Fields BN, Knipe DM, Howley PM, Chanock RM,...
  • Askonas BA, McMichael AJ, Webster RG. The immune response to influenza viruses and the problem of protection against...
  • R.B. Couch

    Advances in influenza virus vaccine research

    Ann. New York Acad. Sci.

    (1993)
  • Kilbourne ED, Arden NH. Inactivated influenza vaccines. In: Plotkin SA, Orenstein WA, editors. Vaccines. 3rd ed....
  • Clements ML, Stephens I. New and improved vaccines against influenza. In: Levine MM, Woodrow GC, Kaper JB, Cobon GS,...
  • Conne P, Ganthey L, Vernet P, Althaus B, Que JU, Finkel B, et al. Immunogenicity of trivalent subunit versus...
  • T.M.E. Govaert et al.

    The efficacy of influenza vaccination in elderly individuals: a randomized double-blind placebo-controlled trial

    JAMA

    (1994)
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