Dataset Information

Reaching hard-to-reach individuals: Nonselective versus targeted outbreak response vaccination for measles.

ABSTRACT: Current mass vaccination campaigns in measles outbreak response are nonselective with respect to the immune status of individuals. However, the heterogeneity in immunity, due to previous vaccination coverage or infection, may lead to potential bias of such campaigns toward those with previous high access to vaccination and may result in a lower-than-expected effective impact. During the 2010 measles outbreak in Malawi, only 3 of the 8 districts where vaccination occurred achieved a measureable effective campaign impact (i.e., a reduction in measles cases in the targeted age groups greater than that observed in nonvaccinated districts). Simulation models suggest that selective campaigns targeting hard-to-reach individuals are of greater benefit, particularly in highly vaccinated populations, even for low target coverage and with late implementation. However, the choice between targeted and nonselective campaigns should be context specific, achieving a reasonable balance of feasibility, cost, and expected impact. In addition, it is critical to develop operational strategies to identify and target hard-to-reach individuals.

SUBMITTER: Minetti A

PROVIDER: S-EPMC3873105 | biostudies-literature | 2014 Jan

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Reaching hard-to-reach individuals: Nonselective versus targeted outbreak response vaccination for measles.

Minetti Andrea A Hurtado Northan N Grais Rebecca F RF Ferrari Matthew M

American journal of epidemiology 20131016 2

Current mass vaccination campaigns in measles outbreak response are nonselective with respect to the immune status of individuals. However, the heterogeneity in immunity, due to previous vaccination coverage or infection, may lead to potential bias of such campaigns toward those with previous high access to vaccination and may result in a lower-than-expected effective impact. During the 2010 measles outbreak in Malawi, only 3 of the 8 districts where vaccination occurred achieved a measureable e ...[more]

PMID: 24131555

Similar Datasets

Project description:PurposeAsthma interventions targeting urban adolescents are rare, despite a great need. Motivating adolescents to achieve better self-management of asthma is challenging, and the literature suggests that certain subgroups are more resistant than others. We conducted a school-based, randomized controlled trial (RCT) to evaluate Puff City, a Web-based, tailored asthma intervention, which included a referral coordinator, and incorporated theory-based strategies to target urban teens with characteristics previously found to be associated with lack of behavior change.MethodsTo identify eligible teens, we administered questionnaires on asthma diagnoses and symptoms to ninth through 12th graders of participating schools during a scheduled English class. We randomized eligible, consenting students to Puff City (treatment) or generic asthma education (control).ResultsWe randomized 422 students (98% African-American, mean age = 15.6 years). At 12-month follow-up, adjusted odds ratios (aORs) (95% confidence intervals) indicated intervention benefit for treatment teens for symptom-days and restricted activity days (analyzed as categorical variables) as aOR = .49 (.24-.79), p = .006 and .53 (.32-.86), p = .010, respectively. Among teens meeting baseline criteria for rebelliousness, treatment teens reported fewer symptom-days, symptom-nights, school absences, and restricted activity days: aOR = .30 (.11-.80), .29 (.14-.64), .40 (.20-.78), and .23 (.10-.55); all p < .05. Among teens reporting low perceived emotional support, treatment students reported only fewer symptom-days than controls: aOR = .23 (.06-.88), p = .031. We did not observe statistically significant differences in medical care use.ConclusionsResults suggest that a theory-based, tailored approach, with a referral coordinator, can improve asthma management in urban teens. Puff City represents a viable strategy for disseminating an effective intervention to high-risk and hard-to-reach populations.

Project description:Sub-Saharan Africa bears the greatest burden of cervical cancer. Human papillomavirus (HPV) vaccination programmes to prevent the disease will need to reach vulnerable girls who may not be able access health and screening services in the future. We conducted formative research on facilitators and barriers to HPV vaccination and potential acceptability of a future HPV vaccination programme amongst girls living in hard-to-reach populations in Kenya.Stakeholder interviews with Ministry of Health staff explored barriers to and support for the uptake of HPV vaccination. A situation assessment was conducted to assess community services in Maasai nomadic pastoralist communities in Kajiado County and in Korogocho informal settlement in Nairobi city, followed by focus group discussions (n=14) and semi-structured interviews (n=28) with health workers, parents, youth, and community and religious leaders. These covered marriage, knowledge of cervical cancer and HPV, factors that might inhibit or support HPV vaccine uptake and intention to accept HPV vaccine if a programme was in place.Reported challenges to an HPV vaccination programme included school absenteeism and drop-out, early age of sex and marriage, lack of parental support, population mobility and distance from services. Despite little prior knowledge of cervical cancer and HPV, communities were interested in receiving HPV vaccination. Adequate social mobilisation and school-based vaccination, supplemented by out-reach activities, were considered important facilitating factors to achieve high coverage. There was some support for a campaign approach to vaccine delivery.Given the high level of support for a vaccine against cervical cancer and the experience of reaching pastoralist and slum-dwellers for other immunizations, implementing an HPV vaccine programme should be feasible in such hard-to-reach communities. This may require additional delivery strategies in addition to the standard school-based delivery, with vaccine offered at multiple venues, potentially through a campaign approach.

Project description:BackgroundIn the UK, hepatitis B virus (HBV) incidence is associated with migrants from particular high-burden countries and population groups deemed 'hard-to-reach' by standard healthcare services: the homeless, people who inject drugs and ex-prisoners. Currently, there is a national targeted HBV vaccine policy for such at-risk groups, but there is limited recent evidence about 1) the levels of vaccine uptake, 2) the factors associated with incomplete vaccination, and 3) reasons for incomplete vaccination.MethodsA questionnaire capturing social and medical history, demographic factors and information about HBV vaccination status was completed by individuals deemed hard-to-reach due to socio-structural factors that criminalise, isolate and stigmatise who consented to participate in a randomised controlled trial of a peer intervention to promote engagement with hepatitis C services. The questionnaire also captured the reasons for incomplete vaccination. Descriptive, univariable and multivariable regression analyses were undertaken.ResultsThree hundred fourty six participants completed the questionnaire. 1) 52.3% (n = 181) reported full HBV vaccination. 2) Within a multivariable model adjusting for sociodemographic variables, the presence of one or two or more socio-structural factors that are included in the national targeted vaccination policy was associated with protection against incomplete HBV vaccination (51.7% vaccine coverage in those with one factor, odds ratio 0.43 [95% confidence interval 0.20-0.92]); 70.1% coverage with two or more factors, 0.19 [0.09-0.39]; overall p-value < 0.001). Being female was also associated with lower vaccine uptake (2.37 [1.24-4.57], 0.01). Examining the socio-structural factors individually, intravenous drug use was associated with protection against incomplete HBV vaccination. 3) The most common reasons declared for incomplete vaccination were never being offered the vaccine or not returning for further doses.ConclusionWithin this study of HBV vaccination uptake among hard-to-reach population groups in London, UK, we document 52.3% coverage of the full vaccine course. Critically, although participants recommended for immunisation within national guidelines had an increased likelihood of receiving a complete vaccine course, we note surprisingly low coverage in the presence of the risk factors that are national indicators for vaccination. Public health bodies should make additional efforts to improve coverage in the hard-to-reach through improved vaccine delivery systems.Trial registrationISRCTN24707359 , Registered 19th October 2012.

Project description:BACKGROUND:Globally only 79% of adults living with HIV (human immunodeficiency virus) know their status and men in sub-Saharan Africa are considered a particularly hard-to-reach population for HIV testing. Home-based HIV couple testing during the antenatal period is a safe and effective method that has been used to test male partners of pregnant women. The goal of this qualitative study was to identify elements that made couple testing successful and describe important characteristics of this home-based intervention from couples' perspectives. METHODS:Couples who received scheduled home-based couple testing during pregnancy in Kisumu, Kenya, were purposively sampled based on HIV status from January to May 2015. An interviewer administered all of the in-depth interviews and two coders were directly involved in the data analysis and reconciled codes several times in the process. RESULTS:Twenty-one couples were enrolled: 9 concordant HIV-negative couples, 8 HIV discordant couples, 3 HIV concordant HIV-positive couples, and 1 whose concordance status was unknown. Median age at the time of home-based couple testing was 24 and 28 years for women and men, respectively. Median relationship duration was 3 years and couples had a median of two pregnancies. The major themes that emerged were that home-based couple testing 1) removed the female burden of requesting couple testing, 2) overcame logistical barriers associated with clinic-based testing, 3) encouraged participants to overcome their fear of testing and disclosure, 4) provided privacy in the home, and 5) provided quality time with the health advisors. Importantly, some women appreciated individual testing at the clinic before couple testing and some couples preferred skilled, anonymous health advisors delivering the intervention rather than known community health workers. CONCLUSIONS:The results of this qualitative study suggest that home-based couple testing during pregnancy overcame many of the barriers that limit men's access to and uptake of clinic-based testing. It encouraged participants to overcome their fear of testing and disclosure through a setting that afforded privacy and quality time with skilled health advisors. These qualitative results may help design effective partner and couple HIV testing programs in the antenatal setting and alongside or within other assisted partner notification services. TRIAL REGISTRATION:Clinicaltrials.gov registry: NCT01784783. Registered prospectively on June 15, 2012.

Project description:BACKGROUND:Measles continues to circulate in the Democratic Republic of Congo, and the country suffered from several important outbreaks over the last 5 years. Despite a large outbreak starting in the former province of Katanga in 2010 and the resulting immunization activities, another outbreak occurred in 2015 in this same region. We conducted measles seroprevalence surveys in four health zones (HZ) in the former Katanga Province in order to assess the immunity against measles in children 6 months to 14 years after the 2015 outbreak. METHODS:We conducted multi-stage cluster surveys stratified by age group in four HZs, Kayamba, Malemba-Nkulu, Fungurume, and Manono. The age groups were 6-11 months, 12-59 months, and 5-14 years in Kayamba and Malemba-Nkulu, 6-59 months and 5-14 years in Manono and Fungurume. The serological status was measured on dried capillary blood spots collected systematically along with vaccination status (including routine Extended Program of Immunization (EPI), and supplementary immunization activities (SIAs)) and previous self-reported history of suspected measles. RESULTS:Overall seroprevalence against measles was 82.7% in Kayamba, 97.6% in Malemba-Nkulu, 83.2% in Manono, and 74.4% in Fungurume, and it increased with age in all HZs. It was 70.7 and 93.8% in children 12-59 months in Kayamba and Malemba-Nkulu, and 49.8 and 64.7% in children 6-59 months in Fungurume and Manono. The EPI coverage was low but varied across HZ. The accumulation of any type of vaccination against measles resulted in an overall vaccine coverage (VC) of at least 85% in children 12-59 months in Kayamba and Malemba-Nkulu, 86.1 and 74.8% in children 6-59 months in Fungurume and Manono. Previous measles infection in 2015-early 2016 was more frequently reported in children aged 12-59 months or 6-59 months (depending on the HZ). CONCLUSION:The measured seroprevalence was consistent with the events that occurred in these HZs over the past few years. Measles seroprevalence might prove a valuable source of information to help adjust the timing of future SIAs and prioritizing support to the EPI in this region as long as the VC does not reach a level high enough to efficiently prevent epidemic flare-ups.

Dataset Information

Reaching hard-to-reach individuals: Nonselective versus targeted outbreak response vaccination for measles.

Publications

Reaching hard-to-reach individuals: Nonselective versus targeted outbreak response vaccination for measles.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure