How Should We Manage the H1N1 Post-pandemic Period?

Vaccine expert says that there are many lessons to be learned from the response to the most recent H1N1 pandemic.

During opening remarks Monday at the 12th Annual World Vaccine Conference in Lyon, France, Luc Hessel, vaccine expert and consultant, said that following a decade of preparation for a pandemic driven by the threat of the H5N1 avian flu, but which translated into a rather moderate A(H1N1) pandemic in 2009, we are now in a post-pandemic period. He asked, “Did we do it right? What did we learn? What should we do now?” Hessel added that that “there are still many lessons to be learned, good and bad, in order to improve our global preparedness for further health threats and to improve the way we can and must approach influenza control.”

What did we learn from the A(H1N1) 2009 pandemic?

Hessel told that audience that in many respects, there will be a “before” and an “after” the first pandemic of the 21st century. In any case, it clearly appears that a pandemic is not only a public health threat, but a major political event in its broad scientific, socio-economic, and communication dimensions.

The A(H1N1) 2009 pandemic was actually a well-anticipated event, according to Hessel. And it marked unprecedented collaboration between international organizations, national governments, health authorities, scientists, and vaccine manufacturers, resulting in the most comprehensive pandemic response ever. He said that for the first time in history, vaccine was made available shortly after the emergence of a pandemic. Within three months of the pandemic declaration, several manufacturers had completed vaccine development and production scale-up and received regulatory approval, allowing public health officials to begin initiating immunization of high-risk groups. Manufacturers have been able to supply vaccines that met authorities’ strict safety requirements. This effective response has been made possible thanks to the decade of preparedness, especially the joint efforts conducted since 2001 by the research-based vaccine industry to collectively address scientific, technical, regulatory policy, and advocacy issues.

Many elements of the response were indeed positive and can be built upon as part of ongoing influenza control:

A high level of preparedness. By the time of the outbreak of H1N1 influenza in 2009, many countries had pandemic plans in place. Throughout the pre-pandemic period, vaccine manufacturers developed prototype pandemic vaccines and adapted the facilities for their manufacture. Regulatory authorities established processes to rapidly assess these vaccines while not compromising on safety.

Global communication and co-operation between the industry and its partners. The well-orchestrated scientific communication, virus-sharing program, and processes to share technical information have been essential for the rapid development, testing and production of a targeted influenza pandemic vaccine. Hessel said that as the pandemic progressed, this process was extended to include the sharing of clinical testing data to help authorities develop recommendations on vaccine use. This especially allowed resolving technical issues through international collaboration to improve low-yielding vaccine virus strains, the use of reagents for standardizing vaccines, including alternative vaccine standardization methods for use early in the production process.

The establishment of vaccine monitoring systems in a number of countries was critical to ensure robust surveillance during wide-scale vaccine use and mass vaccination campaigns. These included continued regulatory assessment; ongoing clinical testing in thousands of adult, children, and other special populations; as well as wide-scale surveillance to rapidly confirm vaccine safety.

But on the other hand, according to Hessel, the management of this event was sometimes poorly done (or at least poorly understood by the population) and improvements in a number of areas could enhance future responses:

Technical issues to increase vaccine virus yields, broadening vaccine standardization techniques, as well as to coordinate administrative workload and distribution issues. Systems that would allow the WHO global network to rapidly produce and test multiple vaccine strains could accelerate the initial stages of manufacture, including reagent production and official guidelines provisions for the rapid co-ordination of import licenses.

Enhancing regulatory processes. The coordination of regulatory requirements, mutual recognition of approvals from other jurisdictions, avoidance of duplication, and reduction of bureaucracy could accelerate vaccine supply.

Negotiating supply agreements in advance. At the outbreak of H1N1 influenza many countries did not have vaccine supply agreements in place. This resulted in a number of complex concurrent negotiations between governments and manufacturers, at a time when time pressures were intense. The establishment of agreements in advance of a pandemic would allow both parties to manage supply requirements, logistics and liability issues, in a more effective manner.

Enhancing communications with healthcare workers and the public. Throughout the pandemic, vaccine uptake has remained generally low even in well-prepared countries. To some extent, this antipathy to vaccines and misunderstanding of vaccination policies by the general public mirrors the poor uptake of seasonal vaccines, especially among healthcare workers and a number of other risk groups. This situation may result in part from new communications channels and social media, which encourage access to health information from a broad range of sources.

The way forward

Taken together and considering the interrelationship between seasonal and pandemic influenza vaccines, there are several lessons to be learned from pandemic preparedness in relation to vaccines and vaccination that should be considered as part of efforts to improve the development and usage of seasonal influenza vaccines, Hessel said.

Regarding research and development efforts, the vaccine industry has been looking at both short- and medium-to-long-term approaches to the development of influenza vaccines. These efforts should continue. The short-term approach relies upon the application of existing technology to improve the formulation and efficacy of seasonal influenza vaccines. The medium-to-long-term approach focuses on improving vaccine performance, including new vaccine concepts, alternative antigen delivery systems, and other production technologies. Hessel said that the ultimate goal is the development of a ‘universal’ influenza vaccine that protects against any influenza strain, including highly pathogenic avian strains with a pandemic potential. The availability of immunological tools and animal models to assess their potential efficacy is critical to meet these goals.

Finally, improving immunization rates in the future will require new models of communication and the co-operation of all stakeholders, to ensure that both healthcare workers and the general public are confident in vaccination policies, trust the information provided and are motivated to act on experts’ recommendations. This need to re-evaluate public health communication was clearly highlighted by the WHO Director General in January 2010, who said that “The days when health officials could issue advice, based on the very best medical and scientific data, and expect populations to comply, may be fading. It may no longer be sufficient to say that a vaccine is safe, or testing complied with all regulatory standards, or a risk is real.”