Mass Measles Vaccination Campaign Research Articles

Effectiveness of a nationwide measles vaccination campaign in Libya, 2005: Retrospective study

Background: Measles is a highly contagious virus. An effective vaccine has been widely administered for over three decades, but the measles burden is still high, causing 134,200 deaths globally in 2014. In Libya, a national mass measles vaccination campaign took place in 2005 targeting all residents of Libya age 9 months to 20 years between February 2005 5, and March 1, 2005. To date, no evaluation of its effectiveness has been conducted. Materials and Methods: Measles surveillance data were obtained for a 6 years' period (2002–2007) spanning the 3 years before and the 3 years following the mass vaccination campaign. The incidence of measles cases was calculated pre- and postvaccination campaigns and relative change in incidence was determined. Results: During the campaign 2,431,167 people age 9 months–20 years were vaccinated, resulting in a coverage rate of 98.4% in that age range. Comparing incidence of measles cases pre-and postvaccination campaign demonstrates an effectiveness of 96%, P = 0.021. Seasonality of measles cases was identified with a peak in April and May. Effectiveness varied by the age group, ranging from 82% in people lower than 5 years of age. Conclusion: A significant reduction was demonstrated following a national immunization campaign. Supplementary immunization campaigns should be initiated to keep the Libyan measles rate low; allowing the country to move into an elimination period.

Control of Measles in Nigeria: A Critical Review of the Literature

The Millennium Development Goals identify the health and wellbeing of children as important indices of meaningful development. An important aspect of child survival is the control of vaccinepreventable diseases. Measles remains an important cause of death among young children globally, despite the availability of a safe and effective vaccine. Although global measles deaths have been reduced by 74% between year 2000 and 2010, the world measles burden still resides in the developing world with measles epidemics occurring in a large and recurrent manner with associated high mortality. These outbreaks can forestall the effects of the control and eradication of measles globally. Nigeria has been experiencing the incidence of measles outbreaks which have occurred in the year 2004, 2005, 2006, 2007, 2008, and 2011. These outbreaks are a cause of Review Article Salako and Sholeye; BJMMR, 5(2): 160-168, 2015; Article no. BJMMR.2015.017 161 concern particularly the outbreak in 2011 which occurred following a mass measles vaccination campaign earlier that year. Efforts to improve control have been on-going and progress has been made particularly with the establishment in 2006 of a system of measles case-based surveillance, however in the myriad of factors plaguing the control of measles in the country, low immunization coverage is still the main factor involved. The inability to control measles is a reflection of the work that needs to be done as regards our immunization coverage and structures that are needed to be put in place. Chronic low immunization and the factors that contribute to it should be addressed with measures and structures that can achieve long term effect. These factors have already been identified and solutions tailored to them need to start taking place. The effect of political and financial committment in achieving this is invaluable especially if the country would achieve the fourth millenium development goal to reduce under-five mortality by two-thirds to which measles is a significant contributor in this part of the world.

An evaluation of the 2012 measles mass vaccination campaign in Guinea.

IntroductionTo estimate the post-campaign level of measles vaccination coverage in Guinea.MethodsInterview of parents and observation of measles vaccination cards of children aged 9 to 59 months during the mass measles campaign. A nationwide cluster randomized sample under health District stratification.Results64.2% (95%CI = 60.9% to 67.4%) of children were vaccinated and had their measles vaccination card. With respect to card and history 90.5% (95%CI = 88.3% to 92.3%) were vaccinated. The estimation was found to be between 72.7% and 81.9%. Coverage with card increased from 55.5% to 79.30% with the level of education of parents but that was not statistically significant, (X2(trend) =3.087 P= 0.07). However coverage with card significantly increased with profession from 55.1% for farmers followed by 59.2% for other manual workers to 73.8% for sellers, ending by 74.5% for settled technicians (X2 (trend) =12.16 P= 0.0005). For unvaccinated children, lack of information accounted for the main reason (37.03%) followed by parents’ occupation (23.45%), parents’ sickness (8.6%), children's sickness (4.9%) and others including vaccinators absent in the post or parents’ belief that it was a door to door campaign.ConclusionThe mass measles vaccination campaign achieved an approximate coverage of 75%. Although not enough for effective control of measles, it has covered an important gap left over by the routine immunization coverage 42%. Appropriate measures are needed to improve coverage in routine immunization and specific actions should be taken to target farmers and other manual workers’ families but also uneducated groups for both routine immunization and mass campaigns.

Post-Vaccination Immunity Against Measles in Under Twenty-Five-Year-Old Population of Ahvaz, Southwest of Iran

Background: Measles is a severe contagious disease, preventable by vaccination. The Ministry of Health and Medical Sciences of Islamic Republic of Iran, has launched a mass Measles vaccination campaign throughout the country from 2003. More than 32 million inhabitants between 5 and 25 years old received the measles vaccine. Objectives: The purpose of this study was to determine the prevalence of positive measles antibody titers in target groups (subjects under 25 year olds) who had received mass vaccination. Patients and Methods: We conducted this cross-sectional study on 900 subjects (363 males and 537 females), referred to health care and medical center of Ahvaz during 2011. Measles IgG antibody of serum was measured using the ELISA method. Results: Overall, 821 (91.2%) of the studied population under 25 years, had immunity to measles. Among girls and boys, 92.2% and 89.8% were seropositive, respectively. These differences were not statistically significant between the two sexes (P = 0.133). Anti-measles antibody titer increased with the increase of age from ≤ 5 to 21 - 25 years (87.3% in ≤ 5-year-old group vs. 96.5 in 21 to 25-year-old group). These differences were statistically significant between the age groups (P = 0.021). Conclusions: Results indicated that the present vaccination program is insufficient for immunity against measles in this area. The general population immunity was lower than the necessary level for the elimination of measles. Therefore, sero-epidemiological studies are necessary to organize national programs for control and elimination of measles.

Evaluation of the mass measles vaccination campaign in Guangdong Province, China

To evaluate the mass measles vaccination campaign of 2009 in Guangdong Province, China. Data on the campaign implementation, measles surveillance, and serological surveillance were reviewed and analyzed by statistical methods. Rapid coverage surveys showed that 98.09% of children were vaccinated during the campaign. The coverage of migrant children increased significantly from 67.10% to 97.32% (p<0.01). From May to December 2009, after the campaign, the number of measles cases was reduced by 93.04% compared with the same period of 2008. The antibody positive rate in children aged less than 15 years reached above 95%. More than 1 million migrant children were identified and vaccinated during the campaign. Flyers, notices of information from doctors, and television programs were the best methods to inform parents of the campaign. Awareness of the campaign by residents increased significantly from 91.86% to 97.10% (p<0.01) through the use of social mobilization materials. A massive vaccination campaign approach for controlling measles in a developing region like Guangdong Province with a vast migrant population has proved effective. Comprehensive mobilization, communication with the mass media, and support from government departments were critical to the success of the campaign.

Evaluation of a mass measles vaccination campaign among school children aged 7–14 years old in Denizli, Turkey

To determine the pre-campaign level of measles seropositivity and to evaluate the effect of a mass measles vaccination campaign on measles seroposivity among primary school children in Denizli, Turkey. The study was completed in two socioeconomically different areas of Denizli, Turkey, with a sample size of 520 students. One primary school from each area and one classroom from each grade were randomly included in the sample. Before and 2-months after the measles mass vaccinations, blood samples were collected from the students and measles specific IgGs were studied. The pre-campaign overall seropositivity was 74.7%. Post-campaign overall seropositivity increased to 96.5%. Pre-campaign seropositivity among 8-graders was significantly lower than that in other grades (57.5%, p<0.001) and the difference was explained by the number of vaccinations 8-graders received. Except for the number of vaccination doses, other factors did not have any effect on seropositivity. The mass measles vaccination programs have a potential to control measles for developing countries. In addition, more than one dose of measles vaccination is required for developing countries.

Immune response to measles vaccine after mass vaccination in Urmia, Islamic Republic of Iran

We investigated the effectiveness of the mass measles vaccination campaign in Urmia, Islamic Republic of Iran, by examining the measles IgG seroprevalence and antibody response from paired data before and after the campaign. The overall seropositive rate of 624 subjects aged 5-25 years increased 1 year after the mass vaccination (from 53.0% to 72.3%). A rise in antibody titre occurred in all age groups except the 21-25 years group, which had the highest titre before mass vaccination. On logistic regression analysis, only immune status prior to vaccination was significantly associated with the seroresponse. It may be cost-effective to check antibody titres before mass vaccinations, especially in high vaccine coverage regions with circulating wild virus.

Population immunity to measles virus and the effect of HIV-1 infection after a mass measles vaccination campaign in Lusaka, Zambia: a cross-sectional survey

Measles control efforts are hindered by challenges in sustaining high vaccination coverage, waning immunity in HIV-1-infected children, and clustering of susceptible individuals. Our aim was to assess population immunity to measles virus after a mass vaccination campaign in a region with high HIV prevalence. 3 years after a measles supplemental immunisation activity (SIA), we undertook a cross-sectional survey in Lusaka, Zambia. Households were randomly selected from a satellite image. Children aged 9 months to 5 years from selected households were eligible for enrolment. A questionnaire was administered to the children's caregivers to obtain information about measles vaccination history and history of measles. Oral fluid samples were obtained from children and tested for antibodies to measles virus and HIV-1 by EIA. 1015 children from 668 residences provided adequate specimens. 853 (84%) children had a history of measles vaccination according to either caregiver report or immunisation card. 679 children (67%) had antibodies to measles virus, and 64 (6%) children had antibodies to HIV-1. Children with antibodies to HIV-1 were as likely to have no history of measles vaccination as those without antibodies to HIV-1 (odds ratio [OR] 1.17, 95% CI 0.57-2.41). Children without measles antibodies were more likely to have never received measles vaccine than those with antibodies (adjusted OR 2.50, 1.69-3.71). In vaccinated children, 33 (61%) of 54 children with antibodies to HIV-1 also had antibodies to measles virus, compared with 568 (71%) of 796 children without antibodies to HIV-1 (p=0.1). 3 years after an SIA, population immunity to measles was insufficient to interrupt measles virus transmission. The use of oral fluid and satellite images for sampling are potential methods to assess population immunity and the timing of SIAs.

The use of a computerized database to monitor vaccine safety in Viet Nam.

Health information systems to monitor vaccine safety are used in industrialized countries to detect adverse medical events related to vaccinations or to prove the safety of vaccines. There are no such information systems in the developing world, but they are urgently needed. A large linked database for the monitoring of vaccine-related adverse events has been established in Khanh Hoa province, Viet Nam. Data collected during the first 2 years of surveillance, a period which included a mass measles vaccination campaign, were used to evaluate the system. For this purpose the discharge diagnoses of individuals admitted to polyclinics and hospitals were coded according to the International Classification of Diseases (ICD)-10 guidelines and linked in a dynamic population database with vaccination histories. A case-series analysis was applied to the cohort of children vaccinated during the mass measles vaccination campaign. The study recorded 107,022 immunizations in a catchment area with a population of 357,458 and confirmed vaccine coverage of 87% or higher for completed routine childhood vaccinations. The measles vaccination campaign immunized at least 86% of the targeted children aged 9 months to 10 years. No medical event was detected significantly more frequently during the 14 days after measles vaccination than before it. The experience in Viet Nam confirmed the safety of a measles vaccination campaign and shows that it is feasible to establish health information systems such as a large linked database which can provide reliable data in a developing country for a modest increase in use of resources.

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First footsteps in tsunamiland

Impact assessment of mass measles vaccination.

The mass measles vaccination campaign was conducted in the slums of Surat City, in Gujarat State, as a part of urban measles control initiative in India. One dose each of the vaccine was administered to children in the age range of 9-59 months residing in these slums, regardless of their previous vaccination status. One year later, (October 2000), the present study was carried out in order to assess the impact of the mass vaccination campaign on the vaccination coverage and on the incidence of measles by comparing the findings with those of the baseline survey carried out in May 98. This was a retrospective study with a recall period of the preceding year. 3,147 children under five were studied in thirty slum clusters selected by the cluster sampling method. The parents/caretakers of these children were interviewed for information on any episode of fever with rash conforming to the case definition. The incidence rate for measles declined from 7.7 percent reported in the baseline (May 1998) to 3.5 percent in the impact assessment study. The incidence was 8 times higher in unvaccinated children. The mean and median age at contracting the illness increased from 26 +/- 14.2 months and 26 months in the baseline to 30.9 +/- 14.7 months and 30 months respectively in the impact assessment. The vaccination coverage had improved from 48.3 percent to 73.7 percent following the campaign. The compaign increased vaccination coverage decreased disease incidence and caused a shift towards higher age-groups in vaccinated children.

Difficulties in measles elimination: prevalence of measles antibodies before and after mass vaccination campaign in Laos

Responding to the declaration of regional polio eradication in 2000, Western Pacific Region (WPR) has been strengthening the efforts for measles elimination. Nevertheless, we questioned the feasibility of the measles elimination in Laos, where measles was still endemic. This study was undertaken with the aim to examine the impact of mass measles vaccination campaign, by comparing the prevalence of measles antibodies between before and after the campaign in 2000, among the children aged 9 months to 4 years in the two pilot sites. The constraints of mass vaccination campaign have been explored in this study. It was also suggested that more efforts should be put on reconstruction of the existing routine immunization service in Laos, which had been weakened by aggressive eradication programme.

Measles epidemiology and outbreak investigation using IgM test in Laos.

Following the Pan American Health Organization (PAHO) recommendation on measles elimination, the Western Pacific Region of WHO (WPR) is emphasizing accelerated measles control programme especially since the achievement of polio eradication in WPR in 2000. This includes upgraded surveillance and mass measles vaccination campaign for children aged 9 months to 4 years. However, there are limited scientific evidences supporting the feasibility of this programme in Laos. To examine measles elimination feasibility in the country, we conducted measles outbreak investigation using immunoglobulin M (IgM). From March 1999 to March 2000, we conducted 7 outbreak investigations. At the outbreak sites, we examined clinical manifestations of cases and collected individual data. About five blood samples were drawn from each outbreak, and IgM antibodies to measles were tested. Of 7 investigated outbreaks, 5 were confirmed as measles, one was chickenpox, and one occurred in the inaccessible area due to flooding. In a village of high land Lao, blood drawn was refused. Of 185 cases, 64 (34.6%) cases were immunized, and 110 (59.5%) were unimunized. The estimated vaccine efficacy is 67.9%. The number of measles cases among school-aged children was 74 (40.0%), which represented 2.5% of the total population in investigated villages. Our findings showed various difficulties of the surveillance and the limited outcomes of mass measles vaccination campaign under the accelerated measles control programme by WPR. Efforts to improve cold chain as well as increasing routine immunization coverage must be the priority of measles control.

Prevalence of measles antibody among children under 15 years of age in Santa Cruz, Bolivia: implications for vaccination strategies

We conducted a community-based survey in Santa Cruz city, Bolivia, to determine the age-specific prevalence of measles antibodies, determine factors associated with absence of detectable measles antibodies, and to compare results of salivary and serum measles immunoglobulin G (IgG) antibody assays. Serum samples from 1654 children were assayed for measles IgG antibody using the haemagglutination inhibition (HI) assay, and salivary samples were also obtained from 187 children and tested for measles IgG antibody using an antibody capture radioimmunoassay. Reported measles vaccine coverage in children aged 12–35 months was 77% (95% confidence interval [CI], 72–81%). Eighty-seven percent (95% CI 85–89%) had detectable HI antibody, but a high proportion had antibody levels below 200 miu(30–40% of 2–14 years old children). Measles seronegativity was associated with not being vaccinated against measles, a negative history of measles disease, living in the inner city, being a lifetime resident of Santa Cruz, and young age. Of 212 children without detectable measles antibody, 58% had a positive history of vaccination or measles disease, so that historical information was not sufficiently reliable to identify susceptibles. The salivary measles antibody assay was not sufficiently sensitive to be used for population screening; only 54% of 171 salivary samples from children who had detectable serum HI antibody were positive. A mass measles vaccination campaign of all children under 15 years of age is planned in Bolivia in 1994. Although only 7% of school-age children in Santa Cruz were seronegative, the effectiveness of a mass campaign in this age group depends in part on the response to revaccination of children with low, but detectable, antibody levels.