Can New Vaccine Technologies Really Increase Vaccination Coverage?

Every year, organizations spend millions of dollars on the development of new vaccine technologies such as simpler and safer administration methods and improved thermostability. These technologies may offer benefits like lower cost for vaccine storage, a reduction in the number of adverse events, and increased efficacy.¹

Understanding these potential benefits allows vaccine manufacturers to channel resources toward technologies with greater promise.

Understanding potential benefits also allows vaccine purchasers—such as donor organizations and governments—to make more cost-effective decisions about which vaccines they will procure.

The methods and tools used to influence the allocation of public funds should be made publicly available in a timely manner.

We are used to seeing the potential benefits of vaccines assessed in the context of laboratory experiments, clinical trials, and health-economic studies, including the studies that must be completed prior to a vaccine being authorized for use in the general public.

But the expected increase in actual vaccination coverage rates is rarely quantified.

Vaccines are one of the most cost-effective tools for improving human health and well-being. So understanding the impact of a vaccine on population health by coverage rate—how many eligible individuals actually get vaccinated—can be  a better indication of a vaccine’s overall success than simply understanding the effectiveness of the vaccine in preliminary and clinical trials.

Because vaccine coverage rates remain below targets in many settings, vaccine manufacturers and purchasers²—global donors like Gavi, country governments, and so on—have a shared interest in understanding how vaccine coverage is affected by population characteristics and by the “presentation” of the vaccine itself—the target disease, dose requirements, administration requirements, refrigeration and other supply chain requirements, and so on.

While there have been some efforts to describe this relationship, existing research and tools are limited in their ability to explain why coverage rates change across geographies and from one target disease and vaccine pair to another.

In our recent study, we present a method for estimating the impact of improved vaccine technologies on vaccination coverage rates.³ We designed the method for use with vaccination programs in low- and middle-income countries in the hopes of improving vaccine coverage in a range of vulnerable communities.

As vaccine manufacturers and purchasers face increasingly complex decisions, the ability to estimate potential coverage can facilitate objective comparisons between options and help these decision makers obtain the most value for their money.

The COVID pandemic has highlighted the presence of supply- and demand-side barriers to vaccination in both high-income countries and LMICs. As COVID vaccines are developed and deployed, we see examples of how vaccine characteristics can affect coverage rates.

• The need for ultra-cold chain and injection by trained medical staff places a heavy burden on already strained supply chains and health systems, limiting access and slowing roll out in certain regions.
• A requirement for two doses instead of one can lead to missed follow-up appointments and partial vaccination.
• Mechanisms such as using mRNA to generate specific proteins can reduce vaccine acceptability and uptake in some populations, despite demonstrated efficacy and safety.

Widespread vaccination is a pillar of outbreak control for a variety of diseases. But few resources are available to assess how vaccine presentation and target population characteristics affect coverage rates.

Our method has several limitations, but it advances the ability of vaccine researchers, investors, manufacturers and purchasers to make objective comparisons between options and obtain the most value for money. Used in conjunction with other health economic approaches, this method could support stronger research pipelines, regional vaccine portfolios that maximize coverage rates, and selecting those vaccines that will have the greatest impact in a particular population.

We strongly believe that the methods and tools used to influence the allocation of public funds should be made publicly available in a timely manner. We hope our method is one of many efforts to move the global health space toward increased transparency, including the public’s ability to scrutinize how vaccines are manufactured and purchased.

Ultimately, if the vaccines don’t become vaccinations, they are not doing the work of preventing disease as effectively as they are designed to do.

Notes

1. Clements CJ, Larsen G, Jodar L. “Technologies That Make Administration of Vaccines Safer.” Vaccine 22/15–16 (7 May 2004):2054-2058; Zehrung D, Jarrahian C, Giersing B, Kristensen D. “Exploring New Packaging and Delivery Options for the Immunization Supply Chain.” Vaccine 35/17 (19 April 2017):2265-2271.

2. Purchaser refers to anyone interested primarily in the health benefit a vaccine confers as opposed to the financial benefit that interests a vaccine seller. That means a purchaser can be a global donor that is interested in investing in a new vaccine so that vaccine eventually gets to market (and people can benefit from it), a global donor that purchases (or facilitates the purchase of vaccines) on a large scale like Gavi, or a country government that purchases them to distribute to their people. 

3. Davis B, Krautmann M, Leroueil P. “A Method for Estimating the Impact of New Vaccine Technologies on Vaccination Coverage Rates.” PLOS ONE (Feb 2022).

About the Author

Pascale R. Leroueil is vice president of the healthcare sector at the William Davidson Institute. Her research is focused on applying business practices to sustainably address human health needs in emerging markets, and has worked with both public and private health systems to increase their efficiency of care. Leroueil holds an adjunct appointment at the University of Michigan Medical School and, before joining WDI, worked in vaccine development at the Medical School. Leroueil earned her PhD in physical chemistry from the University of Michigan and her MBA from the Ross School of Business.