Understanding seasonal vaccines efforts far beyond the vaccination season
By AmerisourceBergen
The production and distribution of seasonal vaccines (flu and COVID-19) is a continuous, year-round process. Despite the public familiarity with vaccinations being offered in the fall and winter months, manufacturers, distributors, government agencies, healthcare providers, and other stakeholders work far beyond that timeframe to protect patients against these ever-evolving viruses. From analyzing global virus trends and selecting strains, to the manufacturing, testing, and distribution of vaccines, each step in this process requires careful timing and coordination.
Does it sound complex? That’s because it is. As a healthcare provider, understanding the intricacies of how your vaccine doses go from manufacturer to patient, and how your distributor can support you through each step in that process, is key to your preparedness for the upcoming season.
"There is a lot that goes on behind-the-scenes, but Cencora's goal as a distributor is simple – to empower providers with the tools, knowledge, and communication that they need to support their patients and their business through each stage of the season."
Summer Richoux, VP, Seasonal Products and Returns, Cencora
According to the Centers for Disease Control and Prevention (CDC), healthcare providers should begin to offer influenza vaccines in October as activity typically peaks between December and February but can last as late as May1. Yet, ensuring that patients have access to these vaccines by the time October comes around is dependent on a process that starts almost a year prior.
Disclaimer: The timeline outlined in this article is based on historical processes around flu vaccines and is intended for representative purposes only and is not comprehensive of all steps required to manufacturer, approve, and distribute seasonal vaccines. In addition, the timings mentioned in this article may vary between flu and COVID-19 vaccines, and from season-to-season, depending on current product and market developments
January–May
Providers place preorders for the upcoming season
This is the prime opportunity for providers to reserve the number of doses that they anticipate needing for the upcoming season (beginning in October as recommended by the CDC1). Preordering is a vital step in the seasonal vaccines’ distribution process for all stakeholders as it gives manufacturers, distributors, and government agencies an indication of the collective volume of vaccines to be produced to ensure supply chain readiness, while providing a chance for providers to get ahead of the seasonal demand for vaccines by essentially reserving their share of doses early. Visibility to preorders also allows manufacturers to plan their production for the upcoming season.
It is important to note that opportunities to preorder are still offered after May, but limitations may apply. To learn more about Cencora’s convenient preordering options, click here.
The World Health Organization (WHO) and the Federal Drug Administration (FDA) advise on strain selections
Every year, the WHO shares their recommendations for influenza vaccine compositions in the northern hemisphere. Click here to see the WHO’s recommendations for the 2024–2025 season as an example.
Shortly after, typically in February or early March, the FDA’s Vaccines and Related Biological Products Advisory Committee (VRBPAC) reviews data on which viruses have caused disease in the past year, how the viruses are changing, and other trends so they can recommend which flu virus strains to include in U.S. vaccines in the upcoming flu season2. Click here to see the FDA’s recommendations for the usage of trivalent influenza vaccines for the 2024–2025 season as an example.
At this point, vaccine manufacturers begin the process of producing vaccines to include the strains recommended by the FDA.
June–July
Distributors place purchase orders with manufacturers
Following the initial preorder window mentioned above, distributors will tally up their reservations and provide a total purchase order amount to manufacturers. This amount includes all reservations received from providers as well as additional anticipated demand based on disease trends, historical purchase amounts, and other factors. These purchase orders, once compiled from all distributors, allow manufacturers to plan their production and efficiently allocate resources to meet the projected demand from the market.
156.2 to 170 million
doses of influenza vaccines were projected for the 2023–2024 season3
August–December
Lots are approved and released for distribution
The FDA, in conjunction with the Center for Biologics Evaluation and Research (CBER), are responsible for verifying that released batches (or “lots”) of vaccines meet appropriate standards. Each vaccine undergoes extensive testing to ensure quality control and sterility prior to being provided to distributors. Manufacturers submit the results of their testing, along with sample vials from each lot to the FDA for what is commonly referred to as a “lot release.”
Lot releases are a continuous process and can continue into early fall. Once lots are released by the FDA, manufacturers can distribute the approved vaccine throughout the U.S. for public use. Lot release information is tracked through the season via an FDA-maintained Lot Distribution Database (LDD) to monitor the production and distribution of vaccines4.
Once lots are approved and released, manufacturers allocate vaccines to distributors based on purchase order volumes. At this time, distributors can negotiate shipping schedules with the manufacturers; however, delays are still possible. The most common delays from manufacturers include FDA delays, manufacturing delays, weather, and logistic scheduling.
Distributors begin shipping vaccines to providers
The exact timing of when distributors begin shipping vaccines varies each year and is based on several factors, including manufacturer production schedules and lot release dates. Generally, healthcare providers can expect to receive initial shipments as early as August, with the bulk of distribution taking place in September or October3.
Although preorder shipping strategies vary between distributors, Cencora follows a ‘fair share’ allocation method – a phased approach which allows for as many healthcare providers as possible to receive initial vaccine doses as early as possible in the season*. Depending on the number of vaccines ordered, providers should expect to receive additional shipments as vaccines continue to be released and distributed through the fall and winter months.
The process doesn’t end there. In addition to all that has been mentioned, distributors also partner with manufacturers throughout the year to offer opportunities for providers to return unused doses at the end of a season.
As you can see, efficient and reliable distribution of seasonal vaccines is a year-round effort that extends far beyond the calendar year’s vaccination season. Whether you’re a small independent pharmacist, clinic, or a large national retailer, having a distribution partner who makes it easy to manage your seasonal vaccines, plan ahead, and protect your patients is crucial. Click here to learn more about how Cencora provides the purchasing advantages, tools, and support needed for a successful seasonal vaccines program.
"Seasonal vaccines distribution is complicated, but how can we simplify the status quo in order to create a more transparent and seamless process for sites of care, which will ultimately translate to a better patient experience, is the question that we're asking."
Tim Navin, Manager, Solutions Operations, Cencora
*Applies to preorders received in advance of our priority preorder deadline. For additional details, see our seasonal vaccines preorder terms and conditions.
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