The Perfect Shot

Manufacturers plan ahead to ensure that millions of Americans can be vaccinated each flu season.

According to the Centers for Disease Control and Prevention (CDC), about 5-20% of Americans get the flu each year, resulting in hundreds of thousands of hospitalizations and another several thousand deaths. Because it can be such a crippling illness — especially for children, the elderly, and persons with weakened immune systems — the CDC recommends that everyone older than 6 months receive an influenza vaccine before flu season begins.

Manufacturing and distributing flu shots to the masses is no small task, however. It’s a complicated process that demands methodical planning throughout the year, complex manufacturing and distribution strategies, and a highly efficient supply chain. As you weather this flu season, we’ll walk you through the processes that ensure access to vaccinations, thereby protecting the general public against this common but debilitating virus.

Feeding the Disease

All commercial flu shots in the US are produced by private sector manufacturers, who rely on one of several methods approved by the US Food and Drug Administration (FDA). The first and most common product is the egg-based vaccine, which is made by growing the influenza virus in chicken eggs, purifying the virus, and inactivating it with a chemical so that it can’t reproduce or infect the patient. Trusted for more than seven decades, the egg-based vaccine is generally administered as a shot, or less frequently as a nasal spray.

Since egg-based vaccines require significant time to produce, manufacturers have begun to develop alternative production techniques in recent years. In 2012, for example, the FDA approved a process in which the virus is cultivated in cultured animal cells rather than chicken eggs, a practice that significantly shortens the production timeline. The following year, the FDA approved another process in which a protein taken from a naturally occuring virus is mixed with another virus inside insect cells. Like their egg-based counterparts, these alternative vaccines must be purified, tested, and approved by the FDA before they can be distributed to the public.

Forecasting Health

Because the flu virus is constantly evolving, the CDC needs to modify the primary vaccine each year so that it provides protection against the most widely circulating strains, making the flu vaccine a particular challenge to produce. The CDC usually makes these predictions by February or March, leaving producers with little time to supply healthcare professionals with the vaccine before flu season begins in the fall.

As they prepare for the winter months, vaccine manufacturers need to work closely with healthcare providers to ensure that they produce an adequate supply. Unfortunately, estimating year-to-year demand is one of the most difficult tasks in the flu shot supply chain. Since seasonal demand for flu shots is unpredictable, retailers often place conservative orders to avoid being left with a surplus supply. As a result, manufacturers may opt to produce the vaccine in smaller quantities — which could result in shortages.

For their part, healthcare providers must estimate their community’s vaccination needs, order vaccines in sufficiently large quantities, stock them in appropriate cold storage facilities, and administer them to patients as needed. In addition, they need to maintain rigorous handling and storage protocol, and distribute supply before the vaccines expire. While close collaboration with suppliers can help to smooth this process, it ultimately falls on healthcare providers to devise a forecast that could differ wildly from actual seasonal demand.

With the flu disabling millions of Americans each season, it’s essential that the flu shot supply chain runs smoothly and that manufacturers can meet demand. Despite the many challenges inherent to the flu shot production process, experienced manufacturers all but ensure that Americans can enjoy immunity from this common disease every year.