Cell culture, LAIV vaccines and recombinant DNA technology should be supported by the US government as part of a long-term overhaul of pandemic response capabilities, according to PCAST.
In response to shortcomings in the vaccine manufacturing response to H1N1 the President’s Council of Advisors on Science and Technology (PCAST) was asked to review capabilities.
PCAST wrote : “The fault lay not in the execution, but in the inherent shortcomings of current technologies for the development and production of influenza vaccines.” Consequently, the review recommends the US government considers implementing long-term changes.
Successful implementation of these changes will require significant investment by the US government and industry, as well as close collaboration between public and private sectors. Despite this outlay, PCAST believes the changes need to be considered.
It wrote: “Without replacing the inherently time-consuming egg-based method of production with either a cell culture-based method or a recombinant DNA-based method of production, delivery of all of the needed vaccine, up to the last dose, will remain a long and unpredictable process.”
PCAST recommends the commissioning of a six-month study to assess needs and capacity for cell culture-based production of pandemic vaccine. Furthermore, adoption of cell culture should be supported through development of economic incentives, such as depreciation of plant costs.
Development of optimised seed viruses and potency assays and investigation of the immune response to live attenuated influenza virus (LAIV) vaccines are also recommended. LAIV vaccines could be further supported through financial backing of clinical trials.
Recombinant influenza vaccines & adjuvants
Adoption of recombinant DNA technologies is also discussed in the review. PCAST wrote: “The greatest potential for substantially shortening the time and increasing the reliability of influenza vaccine production lies in the use of recombinant DNA technologies.”
However, the technology faces economic and regulatory barriers, as well as biological uncertainties, wrote PCAST. To overcome these issues the review recommends the government provides incentives and pathways for development.
Actions should advance the goal of moving three recombinant vaccines, suitable for use against seasonal or pandemic influenza, into proof-of-concept clinical trials within three years. Achieving this goal will require input from industry and investors and establishment of a regulatory pathway.
Governmental support is also called for to increase use of adjuvants. Use is currently restricted by scientific and regulatory barriers, wrote PCAST. The review calls for further research and US Food and Drug Administration (FDA) guidance to overcome these factors.
Is a universal vaccine conceivable?
Recent research has shown some regions of the influenza virus do not mutate, prompting speculation that these unchanging areas could be used to develop a universal vaccine capable of protecting against current and future strains.
At this stage it is uncertain if creation of a universal vaccine is possible but “the game-changing potential of such a vaccine warrants a concerted research effort supported by the federal government”, wrote PCAST.