Effectiveness of Vaccination Public Policy

Vaccination is championed as one of the greatest successes in public health policy. Dramatic reduction and eradication of diseases is directly linked to vaccination implementation over the last century. Among the scientific and medical communities, vaccine effectiveness is not up for debate.

But vaccination rates in United States for many diseases fall well below goals set by Health and Human Services’ HealthyPeople2020 objectives. Increasing rates of vaccination has thus remained a top priority for public health officials.

There are challenges though. Whether it’s misplaced fear of links to autism fueled by misinformation or lack of access and information.

Even in the face of dangerous outbreaks, public sentiment and action can remain staunchly opposed to vaccination.

This is where strong public policy should come in. Recent research suggests the high effectiveness of both official recommendations and child mandates for vaccinations.

Emily Lawler from Vanderbilt University’s Department of Economics recently provided new research that examines the effects of hepatitis A vaccination policies on both the rate of vaccination of young children and on population disease incidence.

As she notes, it’s unclear in theory the extent to which vaccination policies are effective:

The direct effect of the policies is straightforward: lowering a vaccine’s effective price or mandating its receipt should increase the demand for vaccination and decrease disease prevalence. If, however, vaccination demand is also a decreasing function of disease prevalence, then each of these policies further has the indirect effect of reducing vaccination demand through the reduction in disease incidence. As a result, the net effect of these hepatitis A vaccination policies on vaccination rates and disease prevalence is an empirical question. 

This is what makes the research a novel and important question of study.

The two policies studied were official recommendations made by the Advisory Committee on Immunization Practices (ACIP) and hepatitis A child care/kindergarten mandates.

Unlike other vaccines, ACIP hepatitis A recommendations were incrementally implemented across states. Mandate implementation in states also varied significantly over time. Both of these reasons allowed Ms. Lawler to make important state level comparisons.

She tests the effects of ACIP recommendations and mandates on immunization rates first:

The results show large and statistically significant increases in immunization rates. Panel A Column 2, which controls for state and fixed year effects and state-specific linear trends, shows an increase of 27.3 percentage points for strong ACIP recommendations and 19.3 percentage points for weak ACIP recommendations. A further 8.18 percentage point increase is the result of a vaccine mandate in a state.

She then tests the effects of ACIP recommendations and mandates on the rate of hepatitis A in the population:

These results also show large and statistically significant effects. Column 3, which controls for state and fixed year effects, state-specific linear trends, and time-varying controls, shows a decrease in incidence of hepatitis A by 4.3 cases/100,000 people for strong ACIP recommendations and 3.3 cases/100,000 people. In addition, a mandate in a state further reduced cases by 1.5/100,000 people.

The obvious limit to this study is that hepatitis A is the only disease studied. As the author notes, hepatitis A is generally asymptomatic for children. Therefore, parents might make different vaccination choices with diseases that are more immediately dangerous to children.

Even so, all of this suggests the value and importance of strong vaccination policies on disease prevalence and immunization rates.