Protection by a polyvalent influenza vaccine and persistence of homologous and heterologous HI antibodies during a period of two epidemic seasons

Abstract

A split-product influenza A vaccine which contained an influenza B strain (B/Hong Kong/8/73) and two influenza A strains, antigenically identical with A/Fort Dix/741/76 (Hsw1N1) and A/Victoria/3/75 (H3N2), was offered to personnel of the CPHL. Changes in the antibody status were followed with serum samples collected from 153 participants on the day of vaccination and 1, 13 and 18 months thereafter. During the two epidemic seasons in the trial period there were only four serological influenza A infections (2.6%) among the vaccinees. This is one eighth of the corresponding infection rate (22%) in the general population estimated on the basis of other indices. The vaccinees' antibody response was strongly influenced by the age of the individual subjects. During the trial period the decrease in the antibody titres slowed down. The geometric mean titres of homologous HI antibodies were still substantially higher at the end of the period than at the beginning. This also applied to heterologous antibodies against H1N1 viruses in persons born between 1926 and 1952. In participants born after 1952, the vaccine was not able to evoke these antibodies, and in participants born in or before 1925 the boosting effect was poor.

The securitisation of pandemic influenza: Framing, security and public policy

“…Over time, as further research centres and laboratories joined the WHO's efforts, a new global influenza surveillance network was created Á a network that currently comprises over 135 public and private research institutions based in over 105 countries around the world (WHO 2011). Moreover, the risk that the world may experience a repeat of the 1918 pandemic has been periodically used as justification for free mass vaccination campaigns, such as the 1976 Swine Flu Campaign in the US (Kavet 1977, Pyhälä 1980, and the suspension of normal pharmaceutical regulatory practices such as the distribution (without prescription) of antiviral medications throughout the UK in 2009 (UK Government 2009, Elbe 2011).…”

“…Over the next three decades, concerns about the disease were overshadowed by more conventional security concerns related to the Cold War; nevertheless, periodic references to the 'threat' of pandemic influenza continued to appear and, as might be expected, were particularly intense following the influenza pandemics of 1957 and 1968. Frequently in these accounts, the 1918 pandemic was used to illustrate the wider societal (catastrophic) consequences of influenza pandemics, usually in an attempt to heighten political interest in, and argue for, increased resources for surveillance and/or vaccination programmes (Pyhälä 1980) or simply to elevate awareness and general concern (Walters 1978). These attempts to portray the disease as an 'existential threat' had limited impact in light of the threat posed by nuclear annihilation, and may be considered unsuccessful securitisations.…”