Do People Taking Flu Vaccines Need Them the Most?

Qian Gu,Neeraj Sood,T Mark Doherty

doi:10.1371/journal.pone.0026347

Abstract

BackgroundA well targeted flu vaccine strategy can ensure that vaccines go to those who are at the highest risk of getting infected if unvaccinated. However, prior research has not explicitly examined the association between the risk of flu infection and vaccination rates.PurposeThis study examines the relationship between the risk of flu infection and the probability of getting vaccinated.MethodsNationally representative data from the US and multivariate regression models were used to estimate what individual characteristics are associated with (1) the risk of flu infection when unvaccinated and (2) flu vaccination rates. These results were used to estimate the correlation between the probability of infection and the probability of getting vaccinated. Separate analyses were performed for the general population and the high priority population that is at increased risk of flu related complications.ResultsWe find that the high priority population was more likely to get vaccinated compared to the general population. However, within both the high priority and general populations the risk of flu infection when unvaccinated was negatively correlated with vaccination rates (r = −0.067, p<0.01). This negative association between the risk of infection when unvaccinated and the probability of vaccination was stronger for the high priority population (r = −0.361, p<0.01).ConclusionsThere is a poor match between those who get flu vaccines and those who have a high risk of flu infection within both the high priority and general populations. Targeting vaccination to people with low socioeconomic status, people who are engaged in unhealthy behaviors, working people, and families with kids will likely improve effectiveness of flu vaccine policy.

Highlights

Seasonal influenza is associated with a large number of hospitalizations and excess deaths in the United States [1,2,3]
There is a poor match between those who get flu vaccines and those who have a high risk of flu infection within both the high priority and general populations
Examining the association between risk of infection and vaccination is an important metric for evaluating the effectiveness of the current flu vaccination program. This information is important for developing an optimal vaccination strategy, especially given the vaccine shortages experienced in recent flu seasons and the suboptimal vaccination rate among both the general and high priority populations. We addresses this gap in the literature by using nationally representative data from the U.S to examine the association between risk of flu infection when unvaccinated and vaccination rates among both the general and high priority populations

Summary

Introduction

Seasonal influenza is associated with a large number of hospitalizations and excess deaths in the United States [1,2,3]. The Advisory Committee on Immunization Practices (ACIP) recommends influenza vaccination for all people age 6 months and older, with a focus on priority populations with a high risk of complications (e.g. older adults, people with certain medical conditions, and pregnant women) and those that come in frequent contact with these populations (e.g. healthcare professionals) [4]. Despite these recommendations, influenza vaccination coverage is still suboptimal. Prior research has not explicitly examined the association between the risk of flu infection and vaccination rates.

Methods

Results

Discussion

Conclusion