Determinants of infant and early childhood mortality in Cameroon: The role of socioeconomic factors,housing characteristics,and immunization status

Abstract

This study examines factors impinging on the survival of children in Cameroon using longitudinal data collected by the United Nations Demographic Training and Research Institute of Yaounde, Cameroon. It deals especially with the role of socioeconomic factors (mother's education, employment, marital status, ethnicity, and household income), housing characteristics (construction materials, power source, source of water supply, extent of crowding), and immunization status on infant and child mortality. Two‐state parametric and nonparametric hazards models for the risk of death at any time within the course of the study are used, with and without accounting for unmeasured heterogeneity. Overall, overcrowding has robust deleterious effects on infant and child survival. As regards the effects of socioeconomic variables, the robustness of the effects of household income and ethnic differentials are unchanged, even after controlling for unmeasured heterogeneity; the deleterious effects of marital status are also apparent, but these effects are largely explained by unmeasured covariates. The data also suggest that the protective effects of full immunization status are robust and not contaminated by confounding factors, at least in the first 16 months of life. These findings provide solid ground to support immunization programs and efforts as a means to reduce significantly infant and child mortality.     

Assessing the utilization of maternal and child health care among married adolescent women: evidence from India

This study explores the prevalence and factors associated with the utilization of maternal and child health care services among married adolescent women in India using the third round of the National Family Health Survey (2005-06). The findings suggest that the utilization of maternal and child health care services among adolescent women is far from satisfactory in India. A little over 10% of adolescent women utilized antenatal care, about 50% utilized safe delivery services and about 41% of the children of adolescent women received full immunization. Large differences by urban-rural residence, educational attainment, religion, economic status and region were evident. Both gross effect and fixed effect binary logit models yielded statistically significant socioeconomic and demographic factors. Women's education, wealth quintile and region are the most important determinants for the utilization of maternal and child health care services. Health care programmes should focus more on educating adolescents, providing financial support, creating awareness and counselling households with married adolescent women. Moreover, there should be substantial financial assistance for the provision of delivery and child care for married women below the age of 19 years.     

Access to Routine Immunization: A Comparative Analysis of Supply-Side Disparities between Northern and Southern Nigeria

Background

The available data on routine immunization in Nigeria show a disparity in coverage between Northern and Southern Nigeria, with the former performing worse. The effect of socio-cultural differences on health-seeking behaviour has been identified in the literature as the main cause of the disparity. Our study analyses the role of supply-side determinants, particularly access to services, in causing these disparities.

Methods

Using routine government data, we compared supply-side determinants of access in two Northern states with two Southern states. The states were identified using criteria-based purposive selection such that the comparisons were made between a low-coverage state in the South and a low-coverage state in the North as well as between a high-coverage state in the South and a high-coverage state in the North.

Results

Human resources and commodities at routine immunization service delivery points were generally insufficient for service delivery in both geographical regions. While disparities were evident between individual states irrespective of regional location, compared to the South, residents in Northern Nigeria were more likely to have vaccination service delivery points located within a 5km radius of their settlements.

Conclusion

Our findings suggest that regional supply-side disparities are not apparent, reinforcing the earlier reported socio-cultural explanations for disparities in routine immunization service uptake between Northern and Southern Nigeria. Nonetheless, improving routine immunisation coverage services require that there are available human resources and that health facilities are equitably distributed.     

Cryptococcal meningitis with malaria

Cryptococcal meningitis is an uncommon infection globally, including Nigeria. This systemic fungal infection often is associated with immunodeficiency. The most common causes of meningitis in Nigeria in the 2–3 year age group are the malaria parasites and bacteria. The concomittant infections ofCryptococcal neoformans andPlasmodium falciparum are uncommon. We present here the report of a case of fatal cryptococcal meningitis with malaria infection in a 2 year old child from Nigeria (one of the malaria endemic regions of the world). This case emphasizes the importance of doing a combination of fungal and bacterial cultures as well as looking for malarial parasites in the determination of etiological agents of meningitis in any hospital in Africa. We suggest that cerebrospinal fluid from meningitis cases must be cultured using Sabouraud dextrose agar and any growth on the agar must be examined using Indian ink.     

Physical activity and the risk of breast cancer among Nigerian women

BackgroundAlthough physical activity has been associated with a reduced risk of breast cancer risk in high income countries (HIC), its role has not been widely studied in sub-Saharan Africa. Our aim was to investigate the association between physical activity (PA) and the risk of breast cancer in Nigeria.MethodsWe conducted a hospital-based case-control study involving participants from five hospitals in Lagos and Abuja. Women were interviewed in-person between October 2016 and May 2017 using a semi-structured questionnaire. Total PA was estimated by summing occupational, household, transport and leisure PA scores. PA was summarised as metabolic equivalents (MET) hours per week (MET-hr/wk). The putative association between breast cancer incidence and PA was analysed using multivariable logistic regression.Results379 histologically confirmed breast cancer cases and 403 controls took part. Compared to women in the lowest categories, women in the upper middle category of total PA(adjusted OR-AOR 0.44, 95% CI: 0.27, 0.78),uppermost categories of total non-vigorous PA (AOR 0.26, 95%CI:0.09,0.75), household PA(AOR 0.0.38, 95% CI: 0.20, 0.71) and occupational PA (AOR 0.64, 95% 0.40, 1.02) had a reduced risk of breast cancer following adjustment for relevant confounders. Transport and leisure PA were not significantly associated with a reduced risk of breast cancer.ConclusionThe total effect of various PA related to regular activities of Nigerian women was associated with a reduced risk of breast cancer. PA especially at household and occupational environments should be promoted as part of breast cancer prevention strategy in Nigeria.     

A dynamic,multi‐level analysis of recent immunization trends in Colombia

Abstract

During 1985–91, Latin American ministries of health carried out the ultimately successful Regional Polio Eradication Initiative. Unprecedented vaccine coverage levels were attained through a combination of mass campaigns, house‐to‐house vaccinations, and improvements in routine immunization services. Little is known, however, about the effects of these interventions on immunization demand; whether they reached so‐called high‐risk households and, if so, whether program effects were sufficient to offset the household risk factors. This paper examines the probability and timing of full immunization over this period in one case country, Colombia. Information on the immunization status of 3,609 vaccine‐eligible children born 1985–90 was extracted from Colombia's 1990 Demographic and Health Survey. Annual immunization coverage estimates from the Colombian Ministry of Health for 1985–90 for 148 sample municipios were appended to each child record, along with household‐level data. Initial non‐parametric regressions showed that five of six observed risk factors negatively influenced full immunization probability. Multivariate logit models showed that parents who had already lost a child were significantly less likely to obtain immunization cards (a proxy for exposure to the routine immunization program), despite rising cardholdership rates over the period. Among 1,376 immunization cardholders, waiting times to full immunization fell monotonically over the period. Local program coverage of 80 per cent or higher and prior use of prenatal services both increased the probability of full immunization. However, three of five maternal occupational categories decreased the probability, as did three of six observed household risk factors. The results show that demand for routine immunizations rose over the period, that only the highest‐risk households were not exposed to the routine program, and that routine program participation partially offset negative risk factor effects on the probability of full immunization. While targeted PHC interventions may increase health production by recruiting high‐risk households into the routine PHC services, further health production increases will require more intensive follow‐up of such households through routine PHC services.     

Socioeconomic Dynamics of Gender Disparity in Childhood Immunization in India, 1992–2006

Background

Recent evidence indicated that gender disparity in child health is minimal and narrowed over time in India. However, considering the geographical and socio-cultural diversity in India, the gender gap may persist across disaggregated socioeconomic context which may be masked by average level. This study examines the dynamics of gender disparity in childhood immunization across regions, residence, wealth, caste and religion in India during 1992–2006.

Method

We used multi-waves of the cross-sectional data of National Family Health Survey conducted in India between 1992–93 and 2005–06. Gender disparity ratio was used to measure the gender gap in childhood immunization across the selected socioeconomic characteristics. Multinomial regression analysis was used to examine the gender gap after accounting for other covariates.

Result

Results indicate that, at aggregate level, gender disparity in full immunization is minimal and has stagnated during the study period. However, gender disparity – disfavouring female children – becomes apparent across the regions, poor households, and religion - particularly among Muslims. Adjusted gender disparity ratio indicates that, full immunization is lower among female than male children of the western region, poor household and among Muslims. Between 1992–93 and 2005–06, the disparity in full immunization had narrowed in the northern region whereas it had, astonishingly, increased in some of the western and southern states of the country.

Conclusion

Our findings emphasize the need to integrate gender issues in the ongoing immunization programme in India, with particular attention to urban areas, developed states, and to the Muslim community.     

Care Seeking Behaviour for Children with Suspected Pneumonia in Countries in Sub-Saharan Africa with High Pneumonia Mortality

Pneumonia is the leading cause of childhood mortality in sub-Saharan Africa (SSA). Because effective antibiotic treatment exists, timely recognition of pneumonia and subsequent care seeking for treatment can prevent deaths. For six high pneumonia mortality countries in SSA we examined if children with suspected pneumonia were taken for care, and if so, from which type of care providers, using national survey data of 76530 children. We also assessed factors independently associated with care seeking from health providers, also known as ‘appropriate’ providers. We report important differences in care seeking patterns across these countries. In Tanzania 85% of children with suspected pneumonia were taken for care, whereas this was only 30% in Ethiopia. Most of the children living in these six countries were taken to a primary health care facility; 86, 68 and 59% in Ethiopia, Tanzania and Burkina Faso respectively. In Uganda, hospital care was sought for 60% of children. 16–18% of children were taken to a private pharmacy in Democratic Republic of Congo (DRC), Tanzania and Nigeria. In Tanzania, children from the richest households were 9.5 times (CI 2.3–39.3) more likely to be brought for care than children from the poorest households, after controlling for the child’s age, sex, caregiver’s education and urban-rural residence. The influence of the age of a child, when controlling for sex, urban-rural residence, education and wealth, shows that the youngest children (<2 years) were more likely to be brought to a care provider in Nigeria, Ethiopia and DRC. Urban-rural residence was not significantly associated with care seeking, after controlling for the age and sex of the child, caregivers education and wealth. The study suggests that it is crucial to understand country-specific care seeking patterns for children with suspected pneumonia and related determinants using available data prior to planning programmatic responses.     

HIV in Children in a General Population Sample in East Zimbabwe: Prevalence,Causes and Effects

Background

There are an estimated half-million children living with HIV in sub-Saharan Africa. The predominant source of infection is presumed to be perinatal mother-to-child transmission, but general population data about paediatric HIV are sparse. We characterise the epidemiology of HIV in children in sub-Saharan Africa by describing the prevalence, possible source of infection, and effects of paediatric HIV in a southern African population.

Methods

From 2009 to 2011, we conducted a household-based survey of 3389 children (aged 2–14 years) in Manicaland, eastern Zimbabwe (response rate: 73.5%). Data about socio-demographic correlates of HIV, risk factors for infection, and effects on child health were analysed using multi-variable logistic regression. To assess the plausibility of mother-to-child transmission, child HIV infection was linked to maternal survival and HIV status using data from a 12-year adult HIV cohort.

Results

HIV prevalence was (2.2%, 95% CI: 1.6–2.8%) and did not differ significantly by sex, socio-economic status, location, religion, or child age. Infected children were more likely to be underweight (19.6% versus 10.0%, p = 0.03) or stunted (39.1% versus 30.6%, p = 0.04) but did not report poorer physical or psychological ill-health. Where maternal data were available, reported mothers of 61/62 HIV-positive children were deceased or HIV-positive. Risk factors for other sources of infection were not associated with child HIV infection, including blood transfusion, vaccinations, caring for a sick relative, and sexual abuse. The observed flat age-pattern of HIV prevalence was consistent with UNAIDS estimates which assumes perinatal mother-to-child transmission, although modelled prevalence was higher than observed prevalence. Only 19/73 HIV-positive children (26.0%) were diagnosed, but, of these, 17 were on antiretroviral therapy.

Conclusions

Childhood HIV infection likely arises predominantly from mother-to-child transmission and is associated with poorer physical development. Overall antiretroviral therapy uptake was low, with the primary barrier to treatment appearing to be lack of diagnosis.     

Strategies to Improve Child Immunization via Antenatal Care Visits in India: A Propensity Score Matching Analysis

Numerous studies have examined the empirical evidence concerning the influence of demographic and socio-economic factors influencing child immunization, but no documentation is available which shows the actual impact of antenatal care (ANC) visits on subsequent child immunization. Therefore, this paper aims to examine the net impact of ANC visits on subsequent utilization of child immunization after removing the presence of selection bias. Nationwide data from India’s latest National Family Health Survey conducted during 2005–06 is used for the present study. The analysis has been carried out in the two separate models, in the first model 1–2 ANC visit and in the second model three or more ANC visits has been compared with no visit. We have used propensity score matching method with a counterfactual model that assesses the actual ANC visits effect on treated (ANC visits) and untreated groups (no ANC visit), and have employed Mantel-Haenszel bounds to examine whether result would be free from hidden bias or not. Using matched sample analysis result shows that child immunization among the groups of women who have completed 1–2 ANC visits and those who had more than two visits was about 13 percent and 19 percent respectively, higher than the group of women who have not made any ANC visit. Findings of nearest neighbor matching with replacement method, which completely eliminated the bias, indicate that selection bias present in data set leads to overestimates the positive effects of ANC visits on child immunization. Result based on Mantel-Haenszel bounds method suggest that if around 19 percent bias would be involved in the result then also we could observe the true positive effect of 1–2 ANC visits on child immunization. This also indicates that antenatal clinics are the conventional platforms for educating pregnant women on the benefits of child immunization.     

Multilevel Analysis of Trachomatous Trichiasis and Corneal Opacity in Nigeria: The Role of Environmental and Climatic Risk Factors on the Distribution of Disease

The distribution of trachoma in Nigeria is spatially heterogeneous, with large-scale trends observed across the country and more local variation within areas. Relative contributions of individual and cluster-level risk factors to the geographic distribution of disease remain largely unknown. The primary aim of this analysis is to assess the relationship between climatic factors and trachomatous trichiasis (TT) and/or corneal opacity (CO) due to trachoma in Nigeria, while accounting for the effects of individual risk factors and spatial correlation. In addition, we explore the relative importance of variation in the risk of trichiasis and/or corneal opacity (TT/CO) at different levels. Data from the 2007 National Blindness and Visual Impairment Survey were used for this analysis, which included a nationally representative sample of adults aged 40 years and above. Complete data were available from 304 clusters selected using a multi-stage stratified cluster-random sampling strategy. All participants (13,543 individuals) were interviewed and examined by an ophthalmologist for the presence or absence of TT and CO. In addition to field-collected data, remotely sensed climatic data were extracted for each cluster and used to fit Bayesian hierarchical logistic models to disease outcome. The risk of TT/CO was associated with factors at both the individual and cluster levels, with approximately 14% of the total variation attributed to the cluster level. Beyond established individual risk factors (age, gender and occupation), there was strong evidence that environmental/climatic factors at the cluster-level (lower precipitation, higher land surface temperature, higher mean annual temperature and rural classification) were also associated with a greater risk of TT/CO. This study establishes the importance of large-scale risk factors in the geographical distribution of TT/CO in Nigeria, supporting anecdotal evidence that environmental conditions are associated with increased risk in this context and highlighting their potential use in improving estimates of disease burden at large scales.     

Metal residues in flesh of edible blue crab,Callinectes amnicola,from a tropical coastal lagoon: Health implications

Metals such as cadmium (Cd), lead (Pb), zinc (Zn), and copper (Cu) were estimated in the flesh of the edible blue crab Callinectes amnicola from selected areas of the Lagos Lagoon, Nigeria (i.e., Makoko, Iddo, Okababa, Ikoyi, and Ajah) for 18 months between March 2011 and August 2012. Estimated average daily intake (EADI) and target hazard quotient (THQ) were used to determine the risk implications for adult and child consumer populations. Range of Cd, Pb, Zn, and Cu across sites was 0.16–0.46, 1.48–3.17, 2.21–3.65, and 9.48–12.76 mg kg^?1 crab flesh wet weight, respectively. Lead concentrations in crab flesh from Makoko (3.16 ± 1.44 mg kg^?1) and Iddo (5.17 ± 1.26 mg kg^?1) exceeded the maximum accepted limits recommended by the Food and Agriculture Organization/World Health Organization for food fisheries. The EADI across sites for the adult consumer population exceeded the reference dose (RfD) recommended by the U.S. Environmental Protection Agency for most metals with magnitude of ≤7-fold while EADI of Pb among child consumer population across sites exceeded RfD by a maximum of 4.5-fold. THQs for adult population were >1 for all metals across all sites, and >1 for Pb and Cd for selected sites for the child consumer population. Findings from this study indicate higher health risks of metal toxicity to adult consumer populations, and risks of lead toxicity to child consumer populations around the Lagos Lagoon, Nigeria.     

Missed Opportunities for Measles,Mumps, and Rubella (MMR) Immunization in Mesoamerica: Potential Impact on Coverage and Days at Risk

Background

Recent outbreaks of measles in the Americas have received news and popular attention, noting the importance of vaccination to population health. To estimate the potential increase in immunization coverage and reduction in days at risk if every opportunity to vaccinate a child was used, we analyzed vaccination histories of children 11–59 months of age from large household surveys in Mesoamerica.

Methods

Our study included 22,234 children aged less than 59 months in El Salvador, Guatemala, Honduras, Mexico, Nicaragua, and Panama. Child vaccination cards were used to calculate coverage of measles, mumps, and rubella (MMR) and to compute the number of days lived at risk. A child had a missed opportunity for vaccination if their card indicated a visit for vaccinations at which the child was not caught up to schedule for MMR. A Cox proportional hazards model was used to compute the hazard ratio associated with the reduction in days at risk, accounting for missed opportunities.

Results

El Salvador had the highest proportion of children with a vaccine card (91.2%) while Nicaragua had the lowest (76.5%). Card MMR coverage ranged from 44.6% in Mexico to 79.6% in Honduras while potential coverage accounting for missed opportunities ranged from 70.8% in Nicaragua to 96.4% in El Salvador. Younger children were less likely to have a missed opportunity. In Panama, children from households with higher expenditure were more likely to have a missed opportunity for MMR vaccination compared to the poorest (OR 1.62, 95% CI: 1.06–2.47). In Nicaragua, compared to children of mothers with no education, children of mothers with primary education and secondary education were less likely to have a missed opportunity (OR 0.46, 95% CI: 0.24–0.88 and OR 0.25, 95% CI: 0.096–0.65, respectively). Mean days at risk for MMR ranged from 158 in Panama to 483 in Mexico while potential days at risk ranged from 92 in Panama to 239 in El Salvador.

Conclusions

Our study found high levels of missed opportunities for immunizing children in Mesoamerica. Our findings cause great concern, as they indicate that families are bringing their children to health facilities, but these children are not receiving all appropriate vaccinations during visits. This points to serious problems in current immunization practices and protocols in poor areas in Mesoamerica. Our study calls for programs to ensure that vaccines are available and that health professionals use every opportunity to vaccinate a child.     

The Risk of Schizophrenia and Child Psychiatric Disorders in Offspring of Mothers with Lung Cancer and Other Types of Cancer: A Danish Nationwide Register Study

Background

Maternal immune responses and brain-reactive antibodies have been proposed as possible causal mechanisms for schizophrenia and some child psychiatric disorders. According to this hypothesis maternal antibodies may cross the placenta and interact with the developing CNS of the fetus causing future neurodevelopmental disorders. Therefore, we investigated if children of mothers with cancer might be at higher risk of developing psychiatric disorders, with particular focus on small-cell lung cancer, which is known to induce production of antibodies binding to CNS elements.

Methods

Nationwide population-based registers were linked, including the Danish Psychiatric Central Register and The Danish Cancer Registry. Data were analyzed as a cohort study using survival analysis techniques. Incidence rate ratios (IRRs) and accompanying 95% confidence intervals (CIs) were used as measures of relative risk.

Results

In general, parental cancer was not associated with schizophrenia in the offspring (IRR, 0.98; 95% CI, 0.95-1.01). Furthermore, we found no temporal associations with maternal cancer in general; neither around the pregnancy period. However, maternal small-cell lung cancer increased the risk of early-onset schizophrenia and maternal small-cell lung cancer diagnosed within 20 years after childbirth increased the risk of schizophrenia. Parental cancer was not associated with child psychiatric disorders (IRR, 1.01; 95% CI, 0.98-1.05) except for the smoking related cancers. There was a significantly increased risk of child psychiatric disorders in offspring of both mothers (IRR, 1.35; 95% CI, 1.16-1.58) and fathers (IRR, 1.47; 95% CI, 1.30-1.66) with lung cancer of all types.

Conclusions

In general, parental cancer did not increase the risk of schizophrenia nor of child psychiatric disorders. However, maternal small-cell lung cancer increased the risk of schizophrenia in subgroups; and lung cancer in general increased the risk of child psychiatric disorders, which could be due to risk factors associated with parental smoking.     

Dermatophytosis among children of Fulani/Hausa herdsmen living in southeastern Nigeria

BackgroundDermatophytic infections are a worldwide public health problem. In Nigeria, children of nomadic herdsmen are thought to be more at risk because of their early and continuous exposure to different kinds of animals. However, little is known about the level of infection in these children in southeastern Nigeria or elsewhere within the West African sub-region.ObjectiveThis study investigated dermatophytic infections among children of nomadic herdsmen living in isolated camps in southeastern Nigeria from October 2008 to May 2009.Methods390 children aged between 4 and 17 years with clinically suggestive lesions were sampled. Isolates were identified by microscopy, culture or both. Biochemical tests and sequencing of the ITS2 region of the ribosomal DNA were used to identify isolates with atypical morphology.Results162 children were confirmed to be infected. Ten different species of dermatophytes were recovered with Trichophyton mentagrophytes showing the highest incidence. There was a significant difference (P < 0.05) in the frequency of isolates recovered among the different age groups screened. No significant (P > 0.05) observations were found according to gender or location of the two camps investigated.ConclusionThis study suggests that tinea capitis is the predominant clinical type of dermatophytosis among children exposed to different kinds of animals based on parental nomadic lifestyle. It also dominated in children with mixed infections in different anatomical sites. The high prevalence of 41.25% suggests that animal to child transmission may be very common.     

The Fundamentals of Fertility: Cosmology and Conversion in a Southwestern Nigerian Town

This article examines the place of religion in the process of 'becoming modern', associated with conversion to Christianity and with literacy, in one Ekiti Yoruba town in southwestern Nigeria. It questions theories of modernization that presume a shift from communal 'traditional' to private, secularized religious practice, focusing on beliefs about the genesis of life, specifically cosmology and fertility. This approach provides a means for examining assumptions about the separation of the secular and religious, evidenced through an examination of local interpretations of biblical texts associated with barrenness and extraordinary births. How these stories have been interpreted by Ekiti Yoruba women and men offers a perspective on the processes whereby forms of 'modern hybrids' are constructed, altered, and reconstructed, as well as on how the fundamental bases of fertility are understood in particular social contexts.     

Influences of mother's work,childhood place of residence,and exposure to media on breast-feeding patterns: experience of Nigeria and Uganda

This study uses data from the Nigerian Demographic and Health Survey collected in 1990 and the Ugandan Demographic and Health Survey collected in 1995 to examine the implications of mother's work, childhood place of residence, and exposure to the media for breast-feeding patterns (exclusivity and intensity) in Nigeria and Uganda. Nigeria and Uganda present an interesting contrast because Nigeria is more modernized and economically developed than Uganda, thus providing a good indication of the influence of modernization on breast-feeding patterns. Mother's work status is defined by considering whether mothers earned cash from work and took their children to work, hence emphasizing the compatibility of work with child care. Work least compatible with child care had a negative effect on breast-feeding intensity in Nigeria. The negative effect of mother's work on exclusive breast-feeding (that is, if the mothers used formula or milk instead) observed for some working mothers in Nigeria and Uganda was partly confounded by urban residence, exposure to media, and other socioeconomic factors. Mother's work did not have a negative effect on breast-feeding intensity in Uganda. The relationship between mother's work, urban residence, media exposure, and breast-feeding practice seems to be stronger in Nigeria than Uganda.     

Ideal versus actual: the contradiction in number of children born to Nigerian women

Although desired family size is often different from actual family size, the dynamics of this difference are not well understood. This paper examines the patterns and determinants of the difference between desired and actual number of children (unmet fertility desires) among women aged 15-49 years using pooled data from the 1990, 1999 and 2003 Nigeria Demographic and Health Surveys (NDHSs). The results show that more than two-thirds of the sample have unmet fertility desires (18.1% have more while 52.4% have fewer than desired). It was found that early and late childbearing increased the odds of unmet fertility desires. Also, women with low levels of education, from poor households, rural residents as well as those who had experienced child death were at a higher risk of unmet fertility desires in the multivariate context. The study highlights the policy and programme implications of the findings.     

In vivo electroporation restores the low effectiveness of DNA vaccination against HER-2/neu in aging

Experimental evidence has been provided that cancer vaccines are less effective at older age than in young adults. In this study, we evaluated the possibility to recover the low effectiveness of DNA immunization against HER-2/neu increasing plasmid uptake by cells from old mice through electroporation with the aim to enhance the activation of specific immune responses. Young and old Balb/c mice received two immunizations with a pCMV-ECDTM DNA plasmid using plasmid intramuscular injection followed by electroporation (IM + E) or plasmid intramuscular injection alone (IM), and successively, they were challenged with syngeneic HER-2/neu overexpressing TUBO cells. Young mice were completely protected whereas less than 60% protection was observed in old mice after IM immunization. IM + E immunization completely protected old mice against a TUBO cell challenge. The protection was associated with increased transgene expression in the site of immunization and with the induction of both humoral and cell-mediated immunity in old mice. We conclude that the effectiveness of anticancer DNA vaccination in old ages may be improved increasing plasmid uptake and transgene expression through electroporation, suggesting the relevant role of the first steps of the immunization process in the success of cancer vaccines at older age.