The replacement of embryonated chicken eggs by tissue culture cells for the production of influenza vaccines is likely to take place in the near future. Vaccines have already been produced in Madin ...Darby Canine Kidney (MDCK) cells (Brands et al, in this issue) and extensively tested in phase III trials in humans (Palache et al, in this issue) and it seems a matter of time before such vaccines will become available. For this reason, the generation of high-growth reassortants of influenza A virus strains in MDCK cells has been examined. Influenza A virus reassortants of the field strains A/Taiwan/1/86, A/Johannesburg/82/96 and A/Shenzhen/227/95 (all H1N1) were generated in serum-free cultured MDCK-SF1 cells by dual infection with A/Hong Kong/2/68 (H3N2), a strain selected for its high-growth phenotype. These reassortant viruses all contained at least the matrix gene of A/Hong Kong/2/68 which apparently correlates with an improvement of the viral yield.
We previously reported on the use of MDCK cells as a suitable substrate for the propagation of influenza viruses. This has led to the development of Influvac®TC, a cell culture-based subunit ...influenza vaccine with equivalent safety and efficacy to existing egg-based subunit vaccines, granted the first marketing authorisation for a cell culture-based influenza vaccine worldwide. Influvac®TC appears to be an economically feasible alternative as well and, therefore, Solvay is currently constructing a facility from which Influvac®TC is scheduled to be launched in 2005. This means that from 2005 onwards, cell culture can be added to the available technologies to fight influenza and, indeed, will have an added value in (inter)pandemic control. The added value is visualized by assessing the gap between current and recommended vaccine use, which shows that cell culture-based influenza vaccine production is highly preferred over conventional production technologies to narrow the gap between what is currently achieved to fight the burden of influenza and what we would like to achieve from a public health perspective.
Highlights ► Examined global influenza vaccine provision and the influence of health policies. ► Provision increased 72% to 449 million doses in the 6 years to 2009. ► However, only 20% of countries ...met the study's modest provision “hurdle” rate. ► Vaccine provision did not correlate directly with national income. ► Official recommendations were insufficient to drive higher uptake. ► Reimbursement and broad communications correlated most strongly with coverage.
Highlights • Influenza vaccine dose distribution was assessed as a proxy for vaccine utilization. • Distribution increased 87% between 2004 and 2013, but only 12% between 2008 and 2013. • Seasonal ...influenza vaccination coverage rates remain well below recommended targets. • Vaccination coverage targets are not being met under current vaccine recommendations. • New policy measures are required to achieve greater benefits from influenza vaccines.
Vaccination is currently the most effective means of preventing influenza infection. Yet evidence of vaccine performance, and the impact and value of seasonal influenza vaccination across risk groups ...and between seasons, continue to generate much discussion. Moreover, vaccination coverage is below recommended levels.
A model was generated to assess the annual public health benefits and economic importance of influenza vaccination in 5 WHO recommended vaccination target groups (children 6 - 23 months of age; persons with underlying chronic health conditions; pregnant women; health care workers; and, the elderly, 65 years of age) in 27 countries of the European Union. Model estimations were based on standard calculation methods, conservative assumptions, age-based and country-specific data.
Out of approximately 180 million Europeans for whom influenza vaccination is recommended, only about 80 million persons are vaccinated. Seasonal influenza vaccination currently prevents an annual average of between 1.6 million and 2.1 million cases of influenza, 45,300 to 65,600 hospitalizations, and 25,200 to 37,200 deaths. To reach the 75% vaccination coverage target set by the EU Council Recommendation in 2009, an additional 57.4 million person would need to be vaccinated in the elderly and other risk groups. By achieving the 75% target rate set in EU-27 countries, average annual influenza- related events averted would increase from current levels to an additional +1.6 to +1.7 million cases, +23,800 to +31,400 hospitalization, +9,800 to +14,300 deaths, +678,500 to +767,800 physician visits, and +883,800 to +1,015,100 lost days of work yearly. Influenza-related costs averted because of vaccination would increase by an additional + €190 to + €226 million yearly, in vaccination target groups.
Full implementation of current influenza vaccination recommendations of 75% vaccination coverage rate (VCR) in Europe by the 2014-2015 influenza season could immediately reduce an important public health and economic burden.
Highlights • Survey methodology assesses global influenza vaccine dose distribution which can provide a reasonable proxy of vaccine utilization. • Global distribution increased approximately 86.9% ...between 2004 and 2011, but only approximately 12.1% between 2008 and 2011. • Based on dose distribution, it appears that seasonal influenza VCR in many countries remains well below the World Health Assembly (WHA) VCR targets and below the recommendations of the Council of the European Union in EURO. • Inter- and intra-regional disparities in dose distribution trends call into question the impact of current vaccine recommendations at achieving coverage targets. • Additional policy measures, such as reimbursement, health care provider knowledge, attitudes, practices, and communications, are required for VCR targets to be met and for more populations to benefit from available safe and effective influenza vaccines.
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