As we enjoy the last days of summer, the flu season looms. We should be thankful — not because any of us want to get sick with the virus, but because we have so many choices of vaccine to prevent illness. That has not always been the case.

In 2004, there were only two vaccine manufacturers licensed to sell flu vaccine in the U.S. With little warning, the expected supply of vaccine was halved when the UK-based manufacturer notified the Centers for Disease Control and Prevention in early October that its license had been suspended due to manufacturing issues.

The U.S. public health care system faced an unexpected crisis. Providers who had ordered from the U.K. company could no longer expect delivery of flu vaccine, and the sole remaining U.S. manufacturer could not increase supply of vaccine at short notice. In an instant, as demand outstripped supply, people were clamoring for vaccine.

As chief epidemiologist and senior manager of the vaccine program in New Jersey, I was responsible for coordinating the redistribution of expected supplies from the remaining U.S.-based manufacturer, Aventis Pasteur (now Sanofi Pasteur). At the same time, based on CDC guidelines, the state prioritized who would get limited vaccine, which was reinforced by legislative action.

This proved to be quite the challenge, given that providers who had ordered from Aventis were not always willing to share their order with those who could no longer expect a shipment. In one case, a state representative refused to allow his county health department to provide doses to other counties, threatening to litigate if Aventis did not honor the contract with his county health department.

States and local health departments took a variety of approaches to reallocate and prioritize doses, including the use of lotteries.

Impact of flu vaccine shortage

Early in the shortage, people waited in long lines to get vaccinated. (Vaccine hesitancy is not an issue when there is a real or perceived shortage.) As the weeks passed and doses from Aventis were reallocated and redistributed across the country, and the government took other measures to increase supply, demand dropped significantly, resulting in a surplus of doses by the end of the season. Nevertheless, the shortage resulted in lower vaccination rates in all age groups compared to the previous year.

That flu season debacle led to many after-action reports about the sorry state of flu vaccine manufacturing in the U.S. These reports, along with the acknowledgement that the world could expect a flu pandemic in the near future, prompted the U.S. government to invest in and motivate vaccine research and production.

In short order, four manufacturers were licensed in the U.S., some using new technologies, to produce a range of flu vaccine products targeting different age groups. For those 65 and over alone, there are currently eight different vaccines available.

In the last couple of years, we have experienced a supply-demand vaccine imbalance with two emerging diseases — first, COVID-19, and more recently, monkeypox, also resulting in prioritization guidelines. But the reasons for these imbalances differ from that of the flu vaccine shortage in 2004.

In the case of COVID-19 vaccine, the federal government supported the rapid development and authorization of novel vaccines from several manufacturers in record time, and then manufacturing had to scale up to meet estimated need and expected demand. Eventually, supply outstripped demand, even when the Food and Drug Administration authorized the vaccine for use in younger age groups.

What happened with monkeypox

The motivation for developing the monkeypox vaccine was different. In 2019, the government approved a new vaccine to prevent smallpox that also could prevent monkeypox. But the current monkeypox outbreak caused by human-to-human spread was unexpected, and the supplies that the government had ordered from the sole manufacturer had either expired or were not immediately available to meet estimated need and demand.

More supplies are coming, but not fast enough for those most at risk. In the interim, the FDA issued an emergency use authorization for a smaller dose of the vaccine to be injected into the skin, as opposed to the approved use under the skin.

But as with the flu and COVID-19 vaccines, the demand for the monkeypox vaccine will likely fade even before supplies exceed estimated need, as more of those most at risk get vaccinated and modify their behaviors, causing disease rates to decline.

What is common in these three examples of vaccine supply-demand imbalance is the indispensable role of the government in addressing the crisis of the day. Each of these crises was due to different pathogens and different manufacturing issues requiring stakeholder coordination, government financial support, and the expertise of vaccine manufacturers, the public health sector, advocacy groups and the broad health provider community.

Although there have been many criticisms of the government in its response to each of these situations, some justified, there is not enough said about the success of government efforts in addressing a vaccine shortage when it arises, whatever the reason.

Recognizing the costs

Could we do better? Sure, if our elected representatives and the public recognize it costs huge sums of money to be — and remain — prepared, and to respond. And sometimes we must allocate money to maintain stockpiles of vaccines (and drugs) that expire before they are needed. If there is no appetite to “waste” some of the money appropriated for preparedness, then casting blame on the government needs to be tempered by the recognition that policy decisions not to spend money have consequences.

Finally, in the U.S. the vaccine enterprise is a commercial enterprise but with significant government involvement. Manufacturers only will make enough supply to meet expected demand if the government no longer is the sole buyer.

With the COVID-19 and monkeypox outbreaks, the federal government has been the sole buyer of available vaccines. In the case of COVID-19 vaccines, once manufacturers begin selling the vaccine commercially and not directly to the government (and that will happen sooner than we think when there is no longer a declared public health emergency and COVID-19 is considered to be endemic), they will likely take the same approach as with flu vaccines, manufacturing to expected demand (and raising prices).

The good news is the recently passed Inflation Reduction Act will eliminate out-of-pocket costs for Medicare and Medicaid beneficiaries for all CDC-recommended vaccines. Unfortunately, access will still be an issue for the millions of uninsured.

This fall, there should be more than enough flu vaccine supply to meet demand based on manufacturer and government projections. This is also true for the revised and newly recommended COVID-19 booster dose. By rolling up your sleeve and getting vaccinated, you will be protecting yourself and others, at the same time helping the country minimize the risk for future outbreaks and waves of disease. And you won’t have to wait in line or win a lottery.