A survey of parental knowledge of vaccination

Sentiment Analysis of Social Media on Childhood Vaccination: Development of an Ontology

BACKGROUND

Although vaccination rates are above the threshold for herd immunity in South Korea, a growing number of parents have expressed concerns about the safety of vaccines. It is important to understand these concerns so that we can maintain high vaccination rates.

OBJECTIVE

The aim of this study was to develop a childhood vaccination ontology to serve as a framework for collecting and analyzing social data on childhood vaccination and to use this ontology for identifying concerns about and sentiments toward childhood vaccination from social data.

METHODS

The domain and scope of the ontology were determined by developing competency questions. We checked if existing ontologies and conceptual frameworks related to vaccination can be reused for the childhood vaccination ontology. Terms were collected from clinical practice guidelines, research papers, and posts on social media platforms. Class concepts were extracted from these terms. A class hierarchy was developed using a top-down approach. The ontology was evaluated in terms of description logics, face and content validity, and coverage. In total, 40,359 Korean posts on childhood vaccination were collected from 27 social media channels between January and December 2015. Vaccination issues were identified and classified using the second-level class concepts of the ontology. The sentiments were classified in 3 ways: positive, negative or neutral. Posts were analyzed using frequency, trend, logistic regression, and association rules.

RESULTS

Our childhood vaccination ontology comprised 9 superclasses with 137 subclasses and 431 synonyms for class, attribute, and value concepts. Parent's health belief appeared in 53.21% (15,709/29,521) of posts and positive sentiments appeared in 64.08% (17,454/27,236) of posts. Trends in sentiments toward vaccination were affected by news about vaccinations. Posts with parents' health belief, vaccination availability, and vaccination policy were associated with positive sentiments, whereas posts with experience of vaccine adverse events were associated with negative sentiments.

CONCLUSIONS

The childhood vaccination ontology developed in this study was useful for collecting and analyzing social data on childhood vaccination. We expect that practitioners and researchers in the field of childhood vaccination could use our ontology to identify concerns about and sentiments toward childhood vaccination from social data.

Factors Influencing Vaccination in Korea: Findings From Focus Group Interviews

Objectives

Immunization is considered one of the most successful and cost-effective public health interventions protecting communities from preventable infectious diseases. The Korean government set up a dedicated workforce for national immunization in 2003, and since then has made strides in improving vaccination coverage across the nation. However, some groups remain relatively vulnerable and require intervention, and it is necessary to address unmet needs to prevent outbreaks of communicable diseases. This study was conducted to characterize persistent challenges to vaccination.

Methods

The study adopted a qualitative method in accordance with the Consolidated Criteria for Reporting Qualitative Research checklist. Three focus group interviews were conducted with 15 professionals in charge of vaccination-related duties. The interviews were conducted according to a semi-structured guideline, and thematic analysis was carried out. Data saturation was confirmed when the researchers agreed that no more new codes could be found.

Results

A total of 4 main topics and 11 subtopics were introduced regarding barriers to vaccination. The main topics were vaccine hesitancy, personal circumstances, lack of information, and misclassification. Among them, vaccine hesitancy was confirmed to be the most significant factor impeding vaccination. It was also found that the factors hindering vaccination had changed over time and disproportionately affected certain groups.

Conclusions

The study identified ongoing unmet needs and barriers to vaccination despite the accomplishments of the National Immunization Program. The results have implications for establishing tailored interventions that target context- and group-specific barriers to improve timely and complete vaccination coverage.

Retention of the Mother and Child Health Handbook and Additional Immunization of Japanese Encephalitis and Tetanus Vaccine

Background

Improvement of additional immunization rate is indicated as an important factor for effective immunization of diseases. In this study, the relationship between retention of mother and child health handbook and additional immunization rate of Japanese encephalitis and tetanus was examined.

Methods

A survey via questionnaire was performed against parents of students of middle schools in Gwangmyeong-si, Gyeonggi-do, and elementary schools in Seoul. Among 350 copies of the questionnaire delivered via post mail, 261 copies were collected and used in the analysis. The questionnaire included general features of subjects and their children, retention of the mother and child health handbook, and recognition of additional immunization of the Japanese encephalitis and tetanus vaccine.

Results

It was found that 80.8% of subjects answered affirmative to retaining the mother and child health handbook, and the group retaining the handbook had higher recognition rate of the need for additional immunization than the group that did not, for the Japanese encephalitis vaccine (83.2% vs. 51.2%, P < 0.001) and for the tetanus vaccine (66.5% vs. 31.7%, P < 0.001). Although the group retaining the handbook had a significantly higher additional immunization rate of the tetanus vaccine of 48.6% vs. 17.1% (P = 0.001), the immunization rate of the Japanese encephalitis vaccine did not show a significant difference (P = 0.231). The group recognizing the need for additional immunization of the Japanese encephalitis and tetanus vaccine had a significantly higher additional immunization rate than the counterpart (P < 0.001).

Conclusion

It was considered that retention of the mother and child health handbook was related to recognition and execution of additional immunizations.

Estimation of nationwide vaccination coverage and comparison of interview and telephone survey methodology for estimating vaccination status

This study compared interview and telephone surveys to select the better method for regularly estimating nationwide vaccination coverage rates in Korea. Interview surveys using multi-stage cluster sampling and telephone surveys using stratified random sampling were conducted. Nationwide coverage rates were estimated in subjects with vaccination cards in the interview survey. The interview survey relative to the telephone survey showed a higher response rate, lower missing rate, higher validity and a less difference in vaccination coverage rates between card owners and non-owners. Primary vaccination coverage rate was greater than 90% except for the fourth dose of DTaP (diphtheria/tetanus/pertussis), the third dose of polio, and the third dose of Japanese B encephalitis (JBE). The DTaP4: Polio3: MMR1 fully vaccination rate was 62.0% and BCG1:HepB3:DTaP4:Polio3:MMR1 was 59.5%. For age-appropriate vaccination, the coverage rate was 50%-80%. We concluded that the interview survey was better than the telephone survey. These results can be applied to countries with incomplete registry and decreasing rates of landline telephone coverage due to increased cell phone usage and countries. Among mandatory vaccines, efforts to increase vaccination rate for the fourth dose of DTaP, the third dose of polio, JBE and regular vaccinations at recommended periods should be conducted in Korea.