Influenza vaccines have a long history of proven safety and efficacy. However, it is rarely used in low- and middle-income countries (LMICs). The reason for underuse is multifactorial and varies from country to country, but the need for re-prescription and vaccination up to twice a year is a barrier to influenza prevention in LMIC. Efforts have been made to produce next-generation influenza vaccines that provide lasting protection against drifting strains, and such vaccines can meet this unmet need.

Global efforts to prepare for an influenza pandemic have been a public health priority for the past 100 years since the 1918 influenza pandemic. The Commission on Influenza was established in 1948 by the Interim Committee of the World Health Assembly, followed by the World Health Organization (WHO). The technical challenges in developing influenza vaccines were highlighted by WHO in 1954. They are:

• Successful vaccination against influenza depends on knowledge of the virus that causes the epidemic.
• It takes constant vigilance to identify new ones and detect potentially dangerous strains of the virus. As soon as possible.
• Epidemiological reports can only be properly interpreted in terms of laboratory studies of the causative virus.

Awareness

In 2012, the World Health Organization (WHO) released a position paper on influenza vaccination, stating that pregnant women are a top priority for seasonal influenza vaccination in countries considering the introduction or expansion of influenza vaccination programs.  The recommendation to prioritize pregnant women in the immunization program was based on a review of influenza disease burden, vaccine safety, and vaccine performance by the WHO Strategic Advisory Group on Immunization (SAGE).

Despite the WHO recommendation, maternal influenza immunization has not been incorporated into routine immunization programs in many low-resource countries. A 2012 consultation of experts by the Bill & Melinda Gates Foundation (BMGF) identified operational challenges and knowledge gaps hindering the implementation of maternal influenza immunization programs.

Demand

Great efforts have been made to develop influenza vaccines that provide a wide range of durable protection against influenza diseases. There is a risk that the development process will only be carried out with a view to the profitable domestic market. In clinical development, programmatic eligibility criteria (required and important) should be considered. Simplify administration, including routes of administration that do not require needles or trained medical personnel (such as inhaled vaccines and transdermal patches) and products that are stable at ambient temperature to avoid the need for cold chains. Additional efforts to limit the use of vaccines will be much easier with LMICs.

The global production capacity of seasonal influenza vaccines and the number and variety of formulations on the global market are impressive. However, these vaccines are cumbersome to manufacture and supply, their impact on major population-level diseases is unknown, and their availability and use remain a privilege reserved primarily for wealthy countries.

Conclusion

Economic assessments from middle-income areas differed in the population surveyed, results, and definitions used. Most of the results are consistent with evidence from high-income countries that emphasize that influenza vaccines are likely to provide value for money. However, due to severe methodological restrictions, no conclusions can be drawn about the cost-effectiveness of influenza vaccination in middle-income countries. Evidence of cost-effectiveness from low-income countries is completely lacking and more information is needed from a complete economic assessment conducted in a standardized manner.