Predict coverage of measles vaccination for targeted public health action

According to a key factor. Meanwhile, knowing how many people are vaccinated against an existing or re -emerging threat, but such information is often rare or non -existent in many regions, according to researchers from Penn State.

From now on. In addition, in collaboration with a team from the World Health Organization, researchers have developed a new method to estimate and predict the regional levels of measles vaccination coverage, even when precise or timely survey on vaccination is not available. Similarly, The method uses data that is systematically collected when potential measles cases present in clinics to model vaccination coverage. Consequently, can be used to guide public health interventions to slow down or prevent epidemics of measles.

An article describing research recently appeared in the journal Vaccine.

“The measles vaccine is predict coverage measles vaccination targeted very effective. Meanwhile, providing long-term protection of the disease, but we still have epidemics, and the disease causes more than 100,000 deaths each year in the world due to disparities in the distribution of vaccines, the disease control and prevention centers have recently reported more than 1,300 cases confirmed in the United States for the first seed the sources we have for this information is imperfect. Nevertheless, “”

Deepnit Bhatia, first author of the study and graduate student, Eberly College of Science

Researchers use two main sources of information on vaccination coverage. In addition, Demographic and health surveys (DHS) collect health data in households and individuals in 90 low and intermediate income countries. For example, Previously funded by the American Agency for International Development (USAID), the program is considered standard for accuracy, according to researchers.

These surveys are expensive and take time to do predict coverage measles vaccination targeted and are therefore only produced every three to five years. Nevertheless, Apart from these large -scale surveys. In addition, countries produce estimates of coverage of administrative vaccinations according to the number of doses of vaccine administered to a certain age group in the region. These administrative estimates are produced more frequently, but they are not as precise as the DHS and can be biased.

“The DHS produces incredible data. but it is similar to the data from the American census in that it is only done every few years,” said Matt Ferrari, director of the Penn State Center for Infectious Disease Dynamics, Biology Professor and Chief of the Research Team. “The census is carried out every 10 years and takes two years. As it is done, it is obsolete. But it is too expensive to do more frequently. This is how vaccination coverage was evaluated. especially in low and average predict coverage measles vaccination targeted income countries, the places where these diseases have the greatest impact. »»

During the development of their new method. the researchers said they wanted to find a way to divide the difference between very precise but costly and potentially obsolete surveys, and more precise but less precise administrative coverage estimates.

They built a model using data that is regularly collected when patients are processed for potential measles cases in clinics. They used the average age of patients. their vaccination status as indicated during the clinic and if the suspicious cases were really measles, rather than another disease with similar symptoms.

“We know that these measures are associated with the levels of vaccination coverage,” said Bhatia. “For example. in regions with high level of vaccination, young children are less likely to be in contact with the disease and the average age of cases at the clinic will be higher. »» predict coverage measles vaccination targeted

The research team used the three indicators as predictors to form a regression model that could better. predict standard DHS data. Above all. they retained the most recent DHS data to use later as a stronger test of the predictive power of their method. They then used their model to predict vaccination coverage for the period covered by the latest DHS data. found that it was strongly correlated.

“We have found that the forecasts for our method adapt better to DHS data than administrative vaccination coverage estimates. ” said Bhatia. “Since our method uses regularly collected information which is easily accessible to researchers. public health officials, it provides a cheap and more easily accessible methodology to estimate vaccination coverage for a region that can be carried out quickly and can help clarify the policy in a more faithful manner. »»

Recent changes in DHS financing increased the relevance of predict coverage measles vaccination targeted the new method, according to Ferrari.

“Although this is not the case when we started this research, the DHS program is currently on break,” said Ferrari. “DHS has been mainly funded by USAID, and we do not know when or if they will be started again. Our method can, hopefully, help provide a stop. »»