Epidemiology of varicella among immigrants and non-immigrants in Quebec, Canada, before and after the introduction of childhood varicella vaccination: a retrospective cohort study

Seroprevalence status of vaccine-preventable diseases in migrants living in shelter centers in Barcelona, Spain

INTRODUCTION

Almost 281 million people were living in a foreign country in 2022, and more than 100 million were displaced because of war conflicts and human right violations. Vaccination coverage of infectious diseases in migrants from some disadvantaged settings could be lower than reception countries populations, consequently seroprevalence studies and better access to vaccination could contribute to reducing these differences.

METHODS

A descriptive retrospective cross-sectional study was conducted including migrants, living ≤5 years in the reception country and ≥16 years old, who requested a medical exam between January 1st, 2020 and January 31st, 2021. Seroprevalence assessment was performed, and vaccination was offered to those individuals without immunity to hepatitis B, hepatitis A, varicella, measles, mumps, and rubella.

RESULTS

A total of 315 migrants were attended during the study period. Immunity protection at arrival was 252/296 (85.1%) for measles, 274/295 (92.9%) for rubella, 257/296 (86.8%) for mumps, 264/295 (89.5%) for varicella, 267/313 (85.3%) for hepatitis A, and 104/300 (34.6%) for hepatitis B. The final immunity protection after full vaccination schedules was 278/296 (93.9%) for measles, 287/295 (97.3%) for rubella, 274/296 (92.6%) for mumps, 276/295 (93.6%) for varicella, 280/313 (89.5%) for hepatitis A, and 139/300 (46.3%) for hepatitis B.

CONCLUSIONS

The vaccination intervention has increased immunity rates for the studied diseases in the attended migrants in our center, however, such interventions should be maintained to reach local population immunization levels. Moreover, the collaboration between shelter and reference specialized health centers is fundamental to implement such vaccination programs.

A hidden dilemma; post COVID-19 first detection of Varicella zoster M4 genotype from Pakistan

OBJECTIVES

During the COVID-19 pandemic, the risk of childhood infectious diseases was increased. Post-COVID-19 escalation of chickenpox cases, becoming an emerging public health concern. Thus, the study was designed to compare chickenpox prevalence and Varicella zoster virus (VZV) genotypes circulating before, during, and post-COVID-19 in Pakistan.

METHODS

A total of 267 lesion specimens collected from tertiary care hospitals, and chickenpox outbreaks from Pakistan were analysed by a two-amplicon approach with phylogenetic analysis.

RESULTS

Among suspected cases, overall 178/267 were VZV positive. Majority (84.2 %; 150/178) cases were of post-COVID-19 pandemic time. Small outbreaks occurred soon after COVID-19 in Rawalpindi and Islamabad (Pakistan), 40 positive cases out of 178 cases were outbreak cases. There was first time detection of the M4 genotype, which was significantly associated with disease severity (p = 0.0006) and post-COVID-19 chickenpox outbreaks in 2021 (77.9 %; 46/59; p < 0.00001). However, in pre-COVID-19 only M2 genotype was detected. The M2 prevalence varied from 2019 (100 %; 19/19) to 2022 (3.2 %; 3/91). However, the most prevalent strain of 2022 belonged to the M1 genotype (64.8 %; 59/91).

CONCLUSION

A significant rise in chickenpox cases detected soon after COVID-19 in Pakistan, and oscillation of different VZV genotypes with first time detection of M4 genotype is an alarming situation. This demands further detailed genotypic studies on transmission dynamics of a rare M4 with other genotypes to protect the local population and restrict spread in other regions.

The influence of health service interactions and local policies on vaccination decision-making in immigrant women: A multi-site Canadian qualitative study

OBJECTIVES

Research on immigrant and refugee vaccination uptake in Canada shows that immunization decisions vary by vaccine type, location, age and migration status. Despite their diversity, these studies often treat immigrant and refugee populations as a single group relative to other Canadians. In this comparative study, we explored how previous risk communication and immunization experiences influence immunization decisions by immigrant and refugee women from three communities across Canada.

METHODS

Participants included women from the Punjabi immigrant community located in Surrey and Abbotsford, British Columbia (n = 36), the Nigerian immigrant community located in Winnipeg, Manitoba (n = 43), and the Congolese refugee community in Edmonton, Alberta (n = 18). Using focus groups guided by focused ethnography methodology, we sought to understand immunization experiences in Canada and before arrival, and what information sources influenced the immunization decision-making process by the women in the three communities.

RESULTS

Participants had differing past experiences in Canada and before their arrival that influenced how they used information in their vaccination decisions. Clear vaccination communications and dialogue with Canadian health care providers increased trust in Canadian health care and the likelihood of vaccine uptake. By contrast, weak vaccine recommendations and antivaccination information in the community prompted participants to decline future vaccines.

CONCLUSION

Given our participants' different communication preferences and needs, we argue that a one-size-fits-all communication approach is inappropriate for immigrant and refugee populations. Instead, multi-pronged communication strategies are required to reach participants and respond to previous experiences and information that may lead to vaccination hesitancy.

Barriers to and facilitators of human papillomavirus vaccination in an ethnically diverse group of migrant parents: A qualitative mixed methods study

A disparity in the uptake of the Human papillomavirus vaccine (HPVV) among immigrants and refugees leads to a social gradient in health. Recognizing that immigrants and refugees may encounter unique barriers to accessing prevention and care, this study seeks to determine barriers to and facilitators of HPVV among these subgroups to uncover high-resolution quality improvement targets of investment for under-immunized pockets of the population. The study undertook a qualitative inquiry into understanding immigrant and refugee parents' perspectives on HPV infection and HPVV experience through school-based programs. We collected data first through short online surveys (N = 15) followed by one-on-one interviews (N = 15) and then through detailed online surveys (N = 16) followed by focus group discussions (N = 3) with 4-6 participants per group discussion from different groups: Black, South Asian and West Asian. Analysis of surveys and interviews identified that: information, awareness, and education about HPV infection and HPVV were among the most cited barriers that impede the uptake of HPVV. Moreover, vaccine-related logistics were equally important, including not having immunization information packages in different languages and relying solely on the child to bring home packages in paper copies from school-based vaccine programs. A multi-component intervention remains instrumental in enhancing HPV immunization rates, given the inconsistent uptake of HPVV by these subgroups who voice unique barriers and facilitators. An educational campaign that involves educating parents who consent for their child(ren) for HPVV, the children receiving the vaccination, and training staff providing HPVV through school-based immunization programs would be paramount.

COVID-19 vaccine coverage among immigrants and refugees in Alberta: A population-based cross-sectional study

Background

Studies have shown that immigrants have lower vaccination rates than the Canadian-born population. We sought to assess COVID-19 vaccine coverage and factors associated with uptake among foreign-born immigrants relative to the non-immigrant population in Alberta, Canada.

Methods

In this cross-sectional study, we analysed population-based linked administrative health data from Alberta to examine vaccine coverage for 3 931 698 Albertans, of which 731 217 were immigrants. We calculated COVID-19 vaccination coverage as the proportion of eligible Albertans with a record of receiving at least one dose of a COVID-19 vaccine as of November 29, 2021. We used multivariable logistic regression to examine the association of vaccine coverage with migration status (immigrants: four categories based on time since migration and non-immigrants) adjusting for socio-demographic variables.

Results

Overall, COVID-19 vaccination coverage was 78.2% (95% confidence interval (CI) = 78.1%-78.3%) among immigrants and 76.0% (95% CI = 75.9%-76.0%) among non-immigrants. Coverage among immigrants differed by continent of origin, with North America, Oceania, and Europe having the lowest coverage. Although vaccine coverage was relatively uniform across neighbourhood income quintiles for immigrants, immigrants living in rural areas had lower vaccine coverage compared to non-immigrants living in rural areas. Multivariable logistic regression analysis showed a significant interaction between age category and migration status. While immigrants below 50 years of age generally had significantly higher vaccine coverage compared to non-immigrants, there was some variation based on time since migration. Immigrants above 50 years of age showed significantly lower coverage compared to non-immigrants of the same age.

Conclusions

Public health interventions should focus on older immigrants, immigrants living in rural areas, and immigrants from specific continental backgrounds in order to improve COVID-19 vaccination coverage.

Concordance of self-reported varicella history and serology among adolescent and adult refugee patients at a primary care clinic in Toronto, Canada

BACKGROUND

Previous studies have found higher rates of varicella susceptibility among migrants from tropical regions. This study seeks to estimate the prevalence of varicella susceptibility in a cohort of newly arrived refugees and refugee claimants at a primary care clinic in Toronto and to compare patients' self-reported history of varicella infection with serologic test results.

METHODS

We conducted a retrospective chart review of 1888 refugee patients aged 13 years and older rostered at a specialized primary care clinic in Toronto from December 2011 to October 2017. Basic sociodemographic variables, self-reported varicella history, and varicella serologic results were examined.

RESULTS

Based on serologic testing, 8.5% of individuals were varicella non-immune, with highest rates of varicella susceptibility among adolescents aged 13-19 years (13.5%). All adults over age 60 were varicella immune on serology (n = 56). A positive self-reported history of varicella infection was strongly predictive of varicella immunity on serology (PPV 96.8%; 95% CI: 95.2-97.9). A self-reported history of no prior varicella infection did not correlate reliably with serologic test results (NPV 15.8%; 95% CI: 13.3-18.0). A substantial proportion of patients (34.1%) were unsure of their varicella history.

CONCLUSION

Identification and immunization of varicella susceptible refugee newcomers remains a health care priority. Self-reported history of varicella infection had mixed reliability as a predictor of varicella immunity.