Influenza B vaccine lineage selection—An optimized trivalent vaccine

Abstract

HighlightsAlthough it is not known which one of two influenza B lineages will circulate in any one season, only a representative virus of one of the two lineages is part of the trivalent seasonal influenza vaccine.We describe three lineage selection strategies to choose which lineage to include in the seasonal vaccine, including the common strategy of using the last lineage that has been observed to dominate, and a new strategy which takes into account population immunity.We show why the “hedging strategy” leads to higher expected vaccine efficacy for influenza B by describing the underlying immunity management mechanism.We show that the hedging strategy would have lead to higher vaccine efficacy to influenza B in the seasonal vaccine in the decade 2000–2010.We show that some of the benefit of transferring to a quadrivalent vaccine can be captured without the cost of moving to a quadrivalent vaccine with an improved trivalent vaccine lineage selection approach.

A systematic review of the health economic consequences of quadrivalent influenza vaccination

“…For the duration of vaccine-induced protection, a recent study by Kissling et al [57] suggested that protection against influenza B was longer than that against influenza A/H3N2, possibly due to a more rapid antigenic drift of A/H3N2 [61]. Related to this aspect, Höpping et al [62] recently presented an approach to optimize the effectiveness of TIV by choosing the included influenza B strain on the basis of the population's pre-existing immunity instead of taking the virus strain that circulated in the prior season. They argued that by taking into account the time since vaccination, antigenic drift, and serological parameters of each B virus strain, the level of residual protection against B/Yam and B/Vic could be estimated.…”

“…By selecting the influenza B virus strain with the lowest residual protection, high protection levels against both influenza B viruses would be present after vaccination, potentially giving a better protection in case of a vaccine mismatch. Although this strategy is expected to be still inferior to QIV, Höpping et al [62] suggested that it might at least partially capture the benefit of QIV, without any additional vaccine costs. So far, no study has ever compared the cost-effectiveness of QIV versus TIV using this 'Höpping' approach, which, however, might be of interest and complement existing studies.…”

Neurologic Complications of Influenza B Virus Infection in Adults, Romania

“…Some studies support the inclusion of both lineages of influenza B virus in the vaccine to reduce illness ( 38 ), although others suggest a more cautious approach, arguing that addition of a second influenza B virus lineage leads to a modest reduction in influenza-associated outcomes ( 39 ). Recently, a hedging strategy for selection of the influenza B virus lineage included in the standard trivalent vaccine has been suggested as the most effective in terms of long-term protection rates ( 40 ). …”

Estimating the Lineage Dynamics of Human Influenza B Viruses

“…Despite the limited number of existing IBV lineages, vaccine strain selection is still difficult because the dominant lineage changes over time and the switching time of the dominant lineage is difficult to predict. Although the quadrivalent vaccine includes both IBV lineages, Höpping et al 2016 pointed out the necessity of vaccine strain selection because the use of trivalent vaccines is still common worldwide and the cost-effectiveness of quadrivalent vaccines is under debate [4]. …”

“…The time series of confirmed cases between two lineages are negatively correlated (Fig 1), implying epidemiological interference between the two lineages. Moreover, vaccine efficacy studies also imply the existence of immune cross-reaction between lineages [4]. The epidemic dynamics of a lineage are affected by that of the other lineage assuming the existence of immune cross-reaction.…”