Way to Health

Responding to COVID-19 - Increasing Vaccine Uptake

Mar 23, 2021

This is part 4 of a series on Way to Health's involvement in helping address the pandemic. This post focuses on the design and launch of Flu Mega Study project. The intent of this project (which was planned far before the pandemic hit us all) was to try and figure out ways to incent people to get the flu vaccine. That, in itself is a worthwhile thing but the additional benefit is perhaps informing ways by which we can increase COVID vaccine uptake. The results have been staggering with just the choice of words increasing uptake by up to 11%.

Mohan Balachandran Mohan Balachandran


The Behavior Change for Good (BCFG) team have been at the forefront of running what they call Mega trials. The biggest problem that any trial faces is recruitment and having enough participants in the interventional arm to draw statistically significant conclusions. The approach the Katy Milkman (Co-Director, BCFG) took was to look to partner with organizations that had large populations that could be targeted. The goal was to recruit participants in the thousands, which for any one in the clinical trial space is mind boggling. The first project (that W2H was not involved in) involved partnering with a national gym company to try to randomize the use of different messages generated by leading researchers across the country to see what would work. The next study was applying the same techniques and partnering with Mitesh Patel who leads the Penn Medicine Nudge Unit. For this study, the thought was to try to apply similar techniques to boost flu vaccinations rates. The applicability of that to the COVID vaccine effort is obvious.


This quote from the CDC says it all, “We estimate, overall, there were 490,600 hospitalizations and 34,200 deaths during the 2018–2019 season.”. As any medical professional will tell you, the lack of uptake of vaccinations is disturbing. The intent here was to figure out ways to stem this tide.

The goal with this study was to try and recruit up to 150,000 patients across Penn Medicine and Geisinger. There was a parallel project with Walmart Pharmacy but that was not something W2H could undertake given other constraints. For patients with an upcoming appointment, researchers wanted to send them one of 19 randomized messages. We set up integrations with the EHR instances at both Penn Medicine and Geisinger to make that happen. I’m obviously glossing over a lot of details and work involved here.

By the fall of 2020, close to 50,000 patients received one of 19 different messages prior to a healthy visit to their primary care provider. By the end of this month (March 2021), we expect to hit the 150,000 enrollment number. The results were eye-opening.

Operational implications

I’d love to spend some time talking about long-codes and short-codes and the challenges associated with each but I’ve also been told my posts are too long to begin with. “umm, is there a TL:DR version?” “500 words dude…” So, I’ll skip that set of details. If you’re interested, drop me a note.

Outcomes and measures

In this study, roughly a third of the messages tested significantly increased flu shot uptake. In top performing intervention, the use of the word “reserved” increased uptake by 11%. This intervention literally cost less than ten cents per patient. Applying these learnings in the COVID context could save a lot of lives. In more conservative terms, the researchers are optimistic that that what they’ve learned about the flu vaccination uptake will help with COVID vaccination uptakes as well.

I’ll just leave you with two quotes:

Our results suggest a promising way to encourage COVID-19 vaccinations at scale—we can potentially help save lives for less than 10¢ per person

-- Katy Milkman, Wharton Professor, BCFG Co-Director and lead author on the study

In the end, such seemingly small tweaks could nudge vaccination rates higher and help us end this pandemic faster.

-- Mitesh Patel, Penn Medicine Professor, Director of the Penn Medicine Nudge Unit and lead author on the study

Press & Publications

Hope you found this post useful. Please feel free to drop us a line via the Contact link below and we’ll be happy to discuss this more with you. Look for part 5 of this series next week.