Determinants of self-paid rotavirus vaccination status in Kanazawa, Japan, including socioeconomic factors, parents' perception, and children's characteristics.

BACKGROUND: Japan's National Immunization Program does not cover rotavirus vaccine and no government subsidies are available. This study aimed to measure the uptake of and determinants that influenced self-paid rotavirus vaccination, including socioeconomic status and relative poverty. METHODS: We conducted a cross-sectional study at health check-ups for all children aged 18 months in Kanazawa, Japan, between December 2017 and July 2018. Community nurses collected information on self-paid vaccination history, parents' perceptions of and recommendations for rotavirus vaccine, and socioeconomic status in interviews using a unified questionnaire. We used multivariable logistic regression to assess vaccine uptake and possible determinants. RESULTS: In total, 1282 participants were enrolled. The estimated rotavirus vaccine coverage was 72.9%. Perceptions that rotavirus gastroenteritis was serious and that the rotavirus vaccine was effective, pediatricians' recommendations, information from the city office, magazine and Internet articles, and higher parental education level were associated with higher rotavirus vaccine uptake. Lower household income was associated with decreased rotavirus vaccine uptake. Vaccine expense, fear of adverse reactions to the vaccine, number of household members and siblings, and children's characteristics were not correlated with rotavirus vaccination. Poverty was associated with decreased rotavirus vaccine uptake, even after adjustment for other determinants (adjusted odds ratio 0.49, 95% confidence interval: 0.26-0.90). CONCLUSION: Parents' perceptions, socioeconomic status, relative poverty, and pediatricians' recommendations are determinants of vaccination. This study suggests that appropriate information about rotavirus vaccine, subsidies for those of lower socioeconomic status, and national recommendations are necessary to achieve higher coverage.

Subsidy Programs for Seasonal Influenza Vaccination of Children and Pregnant Women in Japanese Municipalities.

In Japan, influenza vaccination is offered to children and pregnant women at clinics or hospitals as an elective, self-funded treatment, as the vaccination is not included in the national vaccination subsidy program. However, some Japanese municipalities offer a discretionary subsidy for seasonal influenza vaccination of children and pregnant women as a local policy. We identified these local subsidy programs during 2019/2020 seasonal influenza season by conducting a cross-sectional survey across Japan. Out of a total of 1741 municipalities, responses were received from 1732; therefore, the response rate was 99.5%. The local influenza vaccine subsidy programs for children were offered in 45.7%, and for pregnant women in 10.2%, of Japanese municipalities. This is the first survey of subsidy programs for pregnant women. While policy diffusion of subsidy programs for children was observed during the 9 years since a previous study, such programs for pregnant women remain limited. Despite many municipalities having subsidy programs, we found that their provision still remains limited when viewed as a whole.

Specific COVID-19 risk behaviors and the preventive effect of personal protective equipment among healthcare workers in Japan.

As coronavirus disease 2019 (COVID-19) outbreaks in healthcare facilities are a serious public health concern, we performed a case-control study to investigate the risk of COVID-19 infection in healthcare workers. We collected data on participants' sociodemographic characteristics, contact behaviors, installation status of personal protective equipment, and polymerase chain reaction testing results. We also collected whole blood and assessed seropositivity using the electrochemiluminescence immunoassay and microneutralization assay. In total, 161 (8.5%) of 1,899 participants were seropositive between August 3 and November 13, 2020. Physical contact (adjusted odds ratio 2.4, 95% confidence interval 1.1-5.6) and aerosol-generating procedures (1.9, 1.1-3.2) were associated with seropositivity. Using goggles (0.2, 0.1-0.5) and N95 masks (0.3, 0.1-0.8) had a preventive effect. Seroprevalence was higher in the outbreak ward (18.6%) than in the COVID-19 dedicated ward (1.4%). Results showed certain specific risk behaviors of COVID-19; proper infection prevention practices reduced these risks.

Rapid response to a coronavirus disease 2019 (COVID-19) outbreak in a psychiatry hospital-Kanazawa City, Japan, March to April 2020.

A coronavirus disease 2019 (COVID-19) outbreak in a psychiatry hospital revealed specific challenges in its response such as difficulty in isolation, transfer, and identification of close contacts, suboptimal infection control practices, and shortage of personal protective equipment, which were overcome by support from the public health center and a neighboring university hospital.

Parents' views on mumps, mumps vaccine, and the factors associated with vaccination in Japan.

BACKGROUND: The measles-mumps-rubella vaccine was withdrawn from the National Immunization Program in 1993 because aseptic meningitis was reported as a post-vaccination adverse reaction in Japan. This study aimed to measure the uptake of and determinants influencing mumps vaccination, including concerns about adverse reactions. METHODS: We conducted this cross-sectional survey for all parents whose children underwent 18-month health checkups in Kanazawa City between October 2019 and February 2020. Community nurses interviewed the parents using a unified questionnaire, and 1422 parents responded. RESULTS: Based on records from maternal and child health handbooks, the mumps vaccination rate was 55.6%. The most common reason for parents not vaccinating their children against mumps was that "it is not a routine vaccine" (35.9%), whereas "concern about adverse reactions" accounted for only 2.2%. In multivariate analysis, the significantly positive factors associated with vaccination against mumps were children whose parents knew that adverse reactions were fever, rash, diarrhea, and vomiting; had received a recommendation for vaccination from their family members; had read the Vaccination Guide issued by the city; vaccinated with other voluntary vaccines or treated for gastroenteritis; and had a deep general understanding of vaccination. Conversely, the significantly negative factor was children whose parents had not received any recommendation for vaccination. CONCLUSION: The mumps vaccination rate could be improved by adding the mumps vaccine in the routine vaccination program and educating parents by disseminating correct information on mumps and the mumps vaccine, and by primary care physicians routinely recommending vaccination.

Effectiveness of four doses of pertussis vaccine during infancy diminished in elementary school age: A test-negative case-control study in Japan.

OBJECTIVE: The Japanese national immunization program recommends that children receive 4 doses of acellular pertussis vaccine between 3 months and 2 years of age. Nevertheless, the number of pertussis cases is increasing in elementary school children aged 6-12 years. Therefore, a test-negative case-control study was conducted to assess the effectiveness of the pertussis vaccine program. METHODS: Subjects included children aged ≥3 months who visited a collaborating hospital due to pertussis-specific cough between October 2017 and November 2019. All subjects underwent diagnostic tests for pertussis, and those diagnosed as positive were regarded as cases. Subjects diagnosed as pertussis-negative were classified as controls. Vaccination history was collected using a questionnaire administered to parents with reference to immunization records. Logistic regression models were employed to calculate the odds ratio (OR) and 95% confidence interval for laboratory-confirmed pertussis. RESULTS: Of 187 recruited subjects (120 cases and 67 controls), questionnaire responses were obtained for 145 subjects (95 cases and 50 controls). Compared with unvaccinated subjects, the vaccine effectiveness (VE) of 4 doses was 70% among all subjects and reached to 90% with marginal significance among subjects under 6 years of age. However, among school-aged subjects, the VE was not suggestive of protection against pertussis (VE: 8%). For vaccinees given 4 doses, the OR for developing pertussis increased significantly with longer duration since the fourth dose (compared with <4.5 years, OR of 6.0-8.2 years = 5.74; OR of ≥8.3 years = 3.88; P for trend by duration < 0.01). CONCLUSION: Effectiveness of administering 4 doses of pertussis vaccine during infancy decreases with time passed since the fourth dose. This regimen does not protect school-aged children against pertussis.

Immune thrombocytopenic purpura risk by live, inactivated and simultaneous vaccinations among Japanese adults, children and infants: a matched case-control study.

This case-control study investigated immune thrombocytopenic purpura (ITP) risk following live, inactivated, and simultaneous vaccination, with a focus on infants aged < 2 years. We matched case patients with ITP to one or two control patients with other diseases by institution, hospital visit timing, sex, and age. We calculated McNemar's pairwise odds ratios (ORs [95% confidence interval]) with 114 case-control pairs. The case group had 27 (44%) males and 22 (35%) infants, and the control group included 49 (43%) males and 42 (37%) infants. For all age groups, the McNemar's OR for ITP occurrence was 1.80 (0.54-6.84, p = 0.64) for all vaccines. Among infants, these were 1.50 (0.17-18.0, p = 0.50) for all vaccines, 2.00 (0.29-22.1, p = 0.67) for live vaccines, and 1.00 (0.01-78.5, p = 0.50) for inactivated vaccines. Sex-adjusted common ORs for simultaneous vaccination were 1.52 (0.45-5.21, p = 0.71) for all vaccines, 1.83 (0.44-7.59, p = 0.40) for inactivated vaccines only, and 1.36 (0.29-6.30, p = 0.69) for mixed live and inactivated vaccines. In infants, these were 1.95 (0.44-8.72, p = 0.38), 1.41 (0.29-6.94, p = 0.67) and 2.85 (0.43-18.9, p = 0.28), respectively. These limited data suggest no significant ITP risk following vaccinations or simultaneous vaccination in any age group, including infants.

Diarrhea as a minor adverse effect due to oral polio vaccine.

Using the adverse events monitoring system of Japan, we observed diarrhea cases in approximately 10% of patients who received oral poliovirus vaccine (OPV). This study was conducted to investigate whether diarrhea among children aged 0 to 1 is caused by OPV or by other factors such contact at the doctor's office and/or with others outside the home. We conducted a survey of the health of children after regular health check-ups and after the administration of the OPV. The data from the health check-ups were used as a control for the OPV case group. We compared the first-OPV dose vaccination group as well as the second-OPV dose vaccination group to the health check-up group. For cases of diarrhea, the odds ratio of the OPV group to the health check-up group was 1.776. Our findings strongly suggest that post-OPV cases of mild diarrhea are closely related to the administration of the OPV.