Influenza Vaccine Production
Jerry P. Weir
Director, Division of Viral Products
OVRR/CBER/FDA
Regulation of Influenza Vaccines
Vaccines are regulated by CBERs Office of
Vaccines Research and Review (OVRR)
Authority resides in Section 351 of the Public Health
Service Act and the Federal Food, Drug and
Cosmetic Act
The safety, efficacy, purity and potency of these
products is assured by thorough review and
evaluation of laboratory and clinical data,
confirmatory testing, and periodic inspection of
manufacturing facilities
Routine Licensing Actions for Annual
Influenza Vaccines in the U.S.
Four licensed inactivated vaccines; one live attenuated
Each year, any of the previous three vaccine strains
may be replaced with a new strain
Strain changes are based on evaluation of circulating
wild-type strains and recommendations of the WHO
and VRBPAC
Submission of a prior approval manufacturing
supplement to an existing license is required for annual
influenza strain changes
Clinical data for approval of these annual supplements
not required for inactivated flu vaccine
Influenza Strain Selection
Antigenic drift continuous in influenza A and B
viruses
Antigenic shift less common but major concern (e.g., H5)
Vaccine composition must be updated regularly to
maintain efficacy which is related to:
Potency of vaccine (immunogenicity), e.g., amount of
hemagglutinin (HA)
Match of the vaccine HA (and possibly NA) with
circulating strains
First evidence of reduced vaccine effectiveness because of
antigenic drift within 2 years after first vaccines licensed in U.S.
Questions to Be Answered for Strain
Changes Every Year
Are new (drifted or shifted) influenza viruses
present?
Are these new viruses spreading in people?
Do current vaccines induce antibodies against the
new viruses (HA)?
Are strains suitable for vaccines available?
Surveillance and Vaccine
Strain Recommendations
Recommendation for selection of strains to be
included in the vaccines depend on:
Robustness of the data
Accurate typing and characterization of isolates
Trending of the data
Extent of data
Timeliness of the data
Timelines for vaccine production are extremely tight
and relatively inflexible
Vaccine Strain Recommendations
WHO Global Surveillance
WHO Strain Recommendations for
Northern Hemisphere mid February
National Regulatory Authorities Recommendations
Vaccines and Related Biological Products Advisory
Committee (VRBPAC) late February
Input from CDC (WHO Collaborating Center)
Department of Defense
Manufacturers (availability and characteristics of
strains under consideration)
Seed Viruses for Manufacturing
WHO Global Surveillance
Provides characterized reference viruses
WHO Collaborating Centers
Provide high growth reassortants
Manufacturers
Develop proprietary seed viruses
Regulatory Agencies
Accept reference viruses and approve seed viruses for use
in licensed vaccine preparations
General Timelines for Influenza
Vaccine Production
CBERs Annual Influenza Vaccine
Program
Perform serology studies in support of strain selection
Develop new high growth influenza virus strains for
vaccines
Evaluate manufacturers influenza viruses prior to
vaccine production
Prepare influenza virus reagents to determine purity
and strength of influenza vaccines
Distribute to vaccine manufacturers
The Pandemic Influenza Vaccine
Challenge
New strains of influenza can emerge into the human
population at any time
Natural avian and swine reservoirs
Emergence of a new influenza will be a global problem
Timelines for vaccine production relatively fixed and capacity
limited
Timely identification of pandemic strain critical
Optimal pandemic vaccine composition, formulation, and
schedule unknown
Lack of previous exposure make correct strain match essential
New technologies may be needed to facilitate vaccine
manufacturing and immunogenicity
Regulatory pathways need to be defined in advance to expedite
vaccine availability
Production of Inactivated Pandemic Vaccine
Ongoing WHO and CDC Global Surveillance
FDA VRBPAC
Pandemic virus identified
Reference (pre-seed) Virus Development
Reassortant virus
Manufacture Seed Virus
FDA tests reference virus
Genetically engineered Virus
Production of
Purified HA
CDC/WHO confirmation
Preparation of antisera
FDA tests seed virus
Monovalent vaccine Bulk
Potency antigen
Distribute antisera
Potency testing
= CBER/FDA
Formulate
Fill Containers
FDA reviews and approves licensing
= WHO/CDC
= Manufacturers
Distribution of Vaccine
Toward a Pandemic
Influenza Vaccine
The regulatory pathway for pandemic vaccines is
similar to that of annual influenza vaccine
CMC and clinical information (both pre- and post
licensure) will be required
FDAs review process will build on existing
knowledge of influenza in comparison to the annual
vaccine
Research efforts will focus on facilitating vaccine
development, including the evaluation and use of new
technologies
Summary
Influenza vaccines present unique considerations for product
development, including accurate strain recommendation
FDA is working with partners to diversify and strengthen
influenza vaccine manufacturing, and providing flexible rapid
regulatory pathways
Accelerated approval of new vaccines
Strain changes to licensed processes
Guidance to manufacturers regarding clinical data needed
Further advance preparation and improvement of strains,
reagents, assays and standards is important
Evaluation of new manufacturing techniques (e.g., non-egg
based technologies) and new product technologies (e.g.,
antigen sparing approaches), are best addressed before a
pandemic key studies are beginning
