New challenges

PRITHA VENKATACHALAM

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IT is well known that vaccine preventable diseases are a major contributor to child mortality in developing and low-income countries. The World Health Organization launched the Expanded Programme for Immunization (EPI) in 1974 to initially deliver routine vaccines such as DPT, polio, and BCG – which together prevent around 2.5 million deaths a year.

Whilst vaccine coverage levels have increased over time, the WHO goal of providing universal immunization for all children by 1990 remains elusive. In addition, countries now have to decide on the adoption of a number of newer and under-used life-saving vaccines such as hepatitis B, Haemophilus influenza type b (Hib), pneumococcus, rotavirus, and rubella.

Historically, the introduction of underused vaccines in developing countries has been much delayed despite their high burden of disease. For example, the first infant Hib conjugate vaccine was licensed in 1988, but until 2005, only five developing countries had introduced Hib-containing vaccines. The lag in introduction has unfortunately not improved much for the newer vaccines – there was a gap of nine years between the first licensed pneumococcal vaccine (PCV7) and the first country introduction, and eight years for the rotavirus vaccine. This is attributed to a range of factors such as the lack of country awareness of disease burden and vaccine efficacy, unaffordable vaccine prices, poor supporting country health and immunization delivery infrastructure, and absence of clear policy guidance and political will. However, the country adoption rate post introduction is expected to rise much faster for the newer vaccines. This heartening projection is partly on account of the combined efforts of global health stakeholders such as the GAVI Alliance and its partners in supporting accelerated vaccine introduction.

The decision-making process for governments to allocate a part of their limited health budget to new vaccines vis-a-vis multiple other competing healthcare demands is understandably difficult. To assist governments in making informed choices on the prioritisation of new vaccine investments, several factors need to be considered.

 

First, they should be provided adequate and reliable information on the local disease burden, and the value and efficacy of the vaccine. Scientific and field studies that establish the cost effectiveness of the vaccine, and its potential impact on morbidity and mortality can help overcome negative publicity against vaccine adoption. For example, a strong anti-vaccine lobby resisted the introduction of the Hib vaccine in India, and had to be countered by focused and evidence based advocacy and communication efforts.

Second, and related to the above, country disease surveillance systems need to be enhanced and integrated at all levels with the health information systems. Surveillance data provides critical information to support and justify vaccine introduction, and also to monitor vaccine coverage, impact and safety.

Third, the vaccine’s supply needs to be stable and available at an affordable price. This is one of the most challenging aspects of new vaccine introduction in developing countries. Global pharmaceutical companies and vaccine manufacturers are deterred from investing in capacities for these markets as the anticipated returns are low owing to unreliable long-term demand forecasts, issues of affordability, supply chain bottlenecks, and quality control and regulatory issues. Further, there have often been delays in pre-qualification of vaccine suppliers after the licensing of the vaccine, thereby disrupting supply. For example, the first pneumococcal conjugate vaccine (PCV7) was licensed in 2000, but not prequalified until 2009 due to the need to test the effectiveness of this vaccine in developing countries. Facilitative mechanisms such as pooled procurement, volume/price guarantees, advance market commitments, and donor support/subsidies accompanied by country commitment to co-finance, have been developed to provide greater incentives for commercial manufacturers, and to encourage emerging market suppliers to produce the vaccines at lower cost. Increases in new vaccine adoption and coverage rates are contingent on further declines in vaccine prices though, by attracting more suppliers, competitive price negotiations, and offering bulk purchase contracts.

 

Fourth, the supporting country health systems need to be equipped to handle the procurement and delivery of additional volumes and specific requirements of the new vaccine. This is in terms of the cold chain capacity, trained healthcare workers at national and sub-national levels, improved tools to forecast demand and report on vaccine stocks, wastages, coverage among other things. The time taken to achieve and sustain full-scale vaccine coverage is reliant on strong health systems, particularly with respect to reaching marginalized and hard-to-reach populations. Above all, strong political will combined with community awareness and demand for these vaccines is critical to ensure timely decisions on uptake.

There is substantial evidence that immunization is a cost-effective and high-impact health intervention. However, an integrated approach to disease control through improved nutrition, clean water and sanitation, etc. is necessary to complement immunization efforts in averting preventable child deaths.

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