Factors associated between behavior of administrating or recommending mumps vaccine and primary care physicians' knowledge about vaccination: A nationwide cross-sectional study in Japan

Mumps vaccination and immune status among Japanese university students: A multicenter cross-sectional study

Background

During the mumps outbreak in Japan in 2016, 159,031 cases were reported. In a survey conducted in 2015, mumps vaccination rates for the first dose were 30%-40%. However, the rates for two or more doses were not determined. We assessed the mumps vaccination rates and mumps infection prevalence according to vaccine doses received.

Design and methods

This was a multicenter cross-sectional study. Students from three universities participated in 2019. Informed consent was obtained from the students and their guardians. The primary outcome was the prevalence of breakthrough mumps infection according to the number of doses of vaccine received. We collected data on past illnesses of vaccine-preventable diseases and vaccination history using a questionnaire, photocopies of the Maternal and Child Health Handbook from the guardians, and virus antibody titers from the universities' health centers.

Results

This study assessed 2004 eligible students and included 593 (29.6%); of these, 250 (42.7%) had a mumps infection history. Furthermore, 264 (44.6%), 31 (5.2%), and 2 (0.3%) students received the first, second, and third doses of mumps vaccine, respectively. The mumps seropositivity prevalence was 43.2% (n = 127), 36.7% (n = 97), 26.7% (n = 8), and 100% (n = 2) for the no-, first-, second-, and third-dose groups, respectively (p for trend = 0.09). The mumps infection prevalence rates were 69.8% (n = 203), 11.3% (n = 28), 3.9% (n = 1), and 0% for the no-, first-, second-, and third-dose groups, respectively.

Conclusions

Approximately 1 in 10 students who had received only one dose of mumps-containing vaccine had a breakthrough infection history.

Association between administration or recommendation of the human papillomavirus vaccine and primary care physicians' knowledge about vaccination during proactive recommendation suspension: a nationwide cross-sectional study in Japan

OBJECTIVE

The Japanese government suspended the proactive recommendation of the human papillomavirus vaccine (HPVv) in 2013, and the vaccination rate of HPVv declined to <1% during 2014-2015. Previous studies have shown that the recommendation by a physician affects a recipient's decision to receive a vaccine, and physicians' accurate knowledge about vaccination is important to increase vaccine administration. This study aimed to evaluate the association between physicians' knowledge of vaccination and the administration or recommendation of HPVv by primary care physicians (PCPs) in the absence of proactive recommendations from the Japanese government.

DESIGN

Cross-sectional study analysed data obtained through a web-based, self-administered questionnaire survey.

SETTING

The questionnaire was distributed to Japan Primary Care Association (JPCA) members.

PARTICIPANTS

JPCA members who were physicians and on the official JPCA mailing list (n=5395) were included.

PRIMARY AND SECONDARY OUTCOME MEASURES

The primary and secondary outcomes were the administration and recommendation of HPVv, respectively, by PCPs. The association between PCPs' knowledge regarding vaccination and each outcome was determined based on their background and vaccination quiz scores and a logistic regression analysis to estimate the adjusted ORs (AORs).

RESULTS

We received responses from 1084 PCPs and included 981 of them in the analysis. PCPs with a higher score on the vaccination quiz were significantly more likely to administer the HPVv for routine and voluntary vaccination (AOR 2.28, 95% CI 1.58 to 3.28; AOR 2.71, 95% CI 1.81 to 4.04, respectively) and recommend the HPVv for routine and voluntary vaccination than PCPs with a lower score (AOR 2.17, 95% CI 1.62 to 2.92; AOR 1.88, 95% CI 1.32 to 2.67, respectively).

CONCLUSIONS

These results suggest that providing accurate knowledge regarding vaccination to PCPs may improve their administration and recommendation of HPVv, even in the absence of active government recommendations.