Supplementary Immunization Activities Research Articles

Factors Associated with Vaccine Refusal (Polio and Routine Immunization) in High-Risk Areas of Pakistan: A Matched Case-Control Study.

Pakistan has subpar childhood immunization rates and immunization activities have faced several challenges over the past years. We evaluated the social-behavioral and cultural barriers and risk factors for refusal of polio, Routine Immunization (RI), or both in high-risk areas of poliovirus circulation. A matched case-control study was conducted from April to July 2017 in eight super high-risk Union Councils of five towns in Karachi, Pakistan. A total of 3 groups, each with 250 cases, including refusals for the Oral Polio Vaccine (OPV) in campaigns (national immunization days and supplementary immunization activities), RI, and both, were matched with 500 controls and identified using surveillance records. Sociodemographic characteristics, household information, and immunization history were assessed. Study outcomes included social-behavioral and cultural barriers and reasons for vaccine refusal. Data were analyzed in STATA using conditional logistic regression. RI refusal was associated with illiteracy and fear of the vaccine's adverse effects, while OPV refusals were linked to the mother's decision authority and the assumption that the OPV caused infertility. Conversely, higher socioeconomic status (SES) and knowledge of and willingness to vaccinate with Inactivated Polio Vaccine (IPV) were inversely associated with RI; and lower SES, walking to the vaccination point, knowledge of IPV, and an understanding of contracting polio were inversely associated with OPV refusals, with the latter two also inversely associated with complete vaccine refusal. Education, knowledge and understanding of vaccines, and socioeconomic determinants influenced OPV and RI refusals among children. Effective interventions are needed to address knowledge gaps and misconceptions among parents.

Vaccine Preventable Disease Seroprevalence in a Nationwide Assessment of Timor-Leste (VASINA-TL): study protocol for a population-representative cross-sectional serosurvey

IntroductionHistoric disruption in health infrastructure combined with data from a recent vaccine coverage survey suggests there are likely significant immunity gaps to vaccine preventable diseases and high risk of outbreaks...

Outbreak management strategies for cocirculation of multiple poliovirus types

Prior modeling studies showed that current outbreak management strategies are unlikely to stop outbreaks caused by type 1 wild polioviruses (WPV1) or circulating vaccine-derived polioviruses (cVDPVs) in many areas, and suggested increased risks of outbreaks with cocirculation of more than one type of poliovirus. The surge of type 2 poliovirus transmission that began in 2019 and continues to date, in conjunction with decreases in preventive supplemental immunization activities (SIAs) for poliovirus types 1 and 3, has led to the emergence of several countries with cocirculation of more than one type of poliovirus. Response to these emerging cocirculation events is theoretically straightforward, but the different formulations, types, and inventories of oral poliovirus vaccines (OPVs) available for outbreak response present challenging practical questions. In order to demonstrate the implications of using different vaccine options and outbreak campaign strategies, we applied a transmission model to a hypothetical population with conditions similar to populations currently experiencing outbreaks of cVDPVs of both types 1 and 2. Our results suggest prevention of the largest number of paralytic cases occurs when using (1) trivalent OPV (tOPV) (or coadministering OPV formulations for all three types) until one poliovirus outbreak type dies out, followed by (2) using a type-specific OPV until the remaining poliovirus outbreak type also dies out. Using tOPV first offers a lower overall expected cost, but this option may be limited by the willingness to expose populations to type 2 Sabin OPV strains. For strategies that use type 2 novel OPV (nOPV2) concurrently administered with bivalent OPV (bOPV, containing types 1 and 3 OPV) emerges as a leading option, but questions remain about feasibility, logistics, type-specific take rates, and coadministration costs.

Update on Wild Poliovirus Type 1 Outbreak — Southeastern Africa, 2021–2022

Since the Global Polio Eradication Initiative (GPEI) began in 1988, the number of wild poliovirus (WPV) cases has declined by >99.99%. Five of the six World Health Organization (WHO) regions have been certified free of indigenous WPV, and WPV serotypes 2 and 3 have been declared eradicated globally (1). WPV type 1 (WPV1) remains endemic only in Afghanistan and Pakistan (2,3). Before the outbreak described in this report, WPV1 had not been detected in southeastern Africa since the 1990s, and on August 25, 2020, the WHO African Region was certified free of indigenous WPV (4). On February 16, 2022, WPV1 infection was confirmed in one child living in Malawi, with onset of paralysis on November 19, 2021. Genomic sequence analysis of the isolated poliovirus indicated that it originated in Pakistan (5). Cases were subsequently identified in Mozambique. This report summarizes progress in the outbreak response since the initial report (5). During November 2021-December 2022, nine children and adolescents with paralytic polio caused by WPV1 were identified in southeastern Africa: one in Malawi and eight in Mozambique. Malawi, Mozambique, and three neighboring countries at high risk for WPV1 importation (Tanzania, Zambia, and Zimbabwe) responded by increasing surveillance and organizing up to six rounds of national and subnational polio supplementary immunization activities (SIAs).* Although no cases of paralytic WPV1 infection have been reported in Malawi since November 2021 or in Mozambique since August 2022, undetected transmission might be ongoing because of poliovirus surveillance gaps and testing delays. Efforts to further enhance poliovirus surveillance sensitivity, improve SIA quality, and strengthen routine immunization are needed to ensure that WPV1 transmission has been interrupted within 12 months of the first case, thereby preserving the WHO African Region's WPV-free status.

Update on Vaccine-Derived Poliovirus Outbreaks - Worldwide, January 2021-December 2022.

Circulating vaccine-derived poliovirus (cVDPV) outbreaks* can occur when oral poliovirus vaccine (OPV, containing one or more Sabin-strain serotypes 1, 2, and 3) strains undergo prolonged circulation in under-vaccinated populations, resulting in genetically reverted neurovirulent virus (1,2). Following declaration of the eradication of wild poliovirus type 2 in 2015 and the global synchronized switch from trivalent OPV (tOPV, containing Sabin-strain types 1, 2, and 3) to bivalent OPV (bOPV, containing types 1 and 3 only) for routine immunization activities† in April 2016 (3), cVDPV type 2 (cVDPV2) outbreaks have been reported worldwide (4). During 2016-2020, immunization responses to cVDPV2 outbreaks required use of Sabin-strain monovalent OPV2, but new VDPV2 emergences could occur if campaigns did not reach a sufficiently high proportion of children. Novel oral poliovirus vaccine type 2 (nOPV2), a more genetically stable vaccine than Sabin OPV2, was developed to address the risk for reversion to neurovirulence and became available in 2021. Because of the predominant use of nOPV2 during the reporting period, supply replenishment has frequently been insufficient for prompt response campaigns (5). This report describes global cVDPV outbreaks during January 2021-December 2022 (as of February 14, 2023) and updates previous reports (4). During 2021-2022, there were 88 active cVDPV outbreaks, including 76 (86%) caused by cVDPV2. cVDPV outbreaks affected 46 countries, 17 (37%) of which reported their first post-switch cVDPV2 outbreak. The total number of paralytic cVDPV cases during 2020-2022 decreased by 36%, from 1,117 to 715; however, the proportion of all cVDPV cases that were caused by cVDPV type 1 (cVDPV1) increased from 3% in 2020 to 18% in 2022, including the occurrence of cocirculating cVDPV1 and cVDPV2 outbreaks in two countries. The increased proportion of cVDPV1 cases follows a substantial decrease in global routine immunization coverage and suspension of preventive immunization campaigns during the COVID-19 pandemic (2020-2022) (6); outbreak responses in some countries were also suboptimal. Improving routine immunization coverage, strengthening poliovirus surveillance, and conducting timely and high-quality supplementary immunization activities (SIAs) in response to cVDPV outbreaks are needed to interrupt cVDPV transmission and reach the goal of no cVDPV isolations in 2024.

Analysis of population immunity to poliovirus following cessation of trivalent oral polio vaccine.

The global withdrawal of trivalent oral poliovirus vaccine (OPV) (tOPV, containing Sabin poliovirus strains serotypes 1, 2 and 3) from routine immunization, and the introduction of bivalent OPV (bOPV, containing Sabin poliovirus strains serotypes 1 and 3) and trivalent inactivated poliovirus vaccine (IPV) into routine immunization was expected to improve population serologic and mucosal immunity to types 1 and 3 poliovirus, while population mucosal immunity to type 2 poliovirus would decline. However, over the period since tOPV withdrawal, the implementation of preventive bOPV supplementary immunization activities (SIAs) has decreased, while outbreaks of type 2 circulating vaccine derived poliovirus (cVDPV2) have required targeted use of monovalent type 2 OPV (mOPV2). We develop a dynamic model of OPV-induced immunity to estimate serotype-specific, district-level immunity for countries in priority regions and characterize changes in immunity since 2016. We account for the changes in routine immunization schedules and varying implementation of preventive and outbreak response SIAs, assuming homogenous coverages of 50% and 80% for SIAs. In areas with strong routine immunization, the switch from tOPV to bOPV has likely resulted in gains in population immunity to types 1 and 3 poliovirus. However, we estimate that improved immunogenicity of new schedules has not compensated for declines in preventive SIAs in areas with weak routine immunization. For type 2 poliovirus, without tOPV in routine immunization or SIAs, mucosal immunity has declined nearly everywhere, while use of mOPV2 has created highly heterogeneous population immunity for which it is important to take into account when responding to cVDPV2 outbreaks. The withdrawal of tOPV and declining allocations of resources for preventive bOPV SIAs have resulted in reduced immunity in vulnerable areas to types 1 and 3 poliovirus and generally reduced immunity to type 2 poliovirus in the regions studied, assuming homogeneous coverages of 50% and 80% for SIAs. The very low mucosal immunity to type 2 poliovirus generates substantially greater risk for further spread of cVDPV2 outbreaks. Emerging gaps in immunity to all serotypes will require judicious targeting of limited resources to the most vulnerable populations by the Global Polio Eradication Initiative (GPEI).

Vaccine-derived poliovirus serotype 2 outbreaks and response in the Democratic Republic of the Congo, 2017-2021.

Vaccine-derived polioviruses (VDPVs) can emerge from Sabin strain poliovirus serotypes 1, 2, and 3 contained in oral poliovirus vaccine (OPV) after prolonged person-to-person transmission where population vaccination immunity against polioviruses is suboptimal. VDPVs can cause paralysis indistinguishable from wild polioviruses and outbreaks when community circulation ensues. VDPV serotype 2 outbreaks (cVDPV2) have been documented in The Democratic Republic of the Congo (DRC) since 2005. The nine cVDPV2 outbreaks detected during 2005-2012 were geographically-limited and resulted in 73 paralysis cases. No outbreaks were detected during 2013-2016. During January 1, 2017-December 31, 2021, 19 cVDPV2 outbreaks were detected in DRC. Seventeen of the 19 (including two first detected in Angola) resulted in 235 paralysis cases notified in 84 health zones in 18 of DRC's 26 provinces; no notified paralysis cases were associated with the remaining two outbreaks. The DRC-KAS-3 cVDPV2 outbreak that circulated during 2019-2021, and resulted in 101 paralysis cases in 10 provinces, was the largest recorded in DRC during the reporting period in terms of numbers of paralysis cases and geographic expanse. The 15 outbreaks occurring during 2017-early 2021 were successfully controlled with numerous supplemental immunization activities (SIAs) using monovalent OPV Sabin-strain serotype 2 (mOPV2); however, suboptimal mOPV2 vaccination coverage appears to have seeded the cVDPV2 emergences detected during semester 2, 2018 through 2021. Use of the novel OPV serotype 2 (nOPV2), designed to have greater genetic stability than mOPV2, should help DRC's efforts in controlling the more recent cVDPV2 outbreaks with a much lower risk of further seeding VDPV2 emergence. Improving nOPV2 SIA coverage should decrease the number of SIAs needed to interrupt transmission. DRC needs the support of polio eradication and Essential Immunization (EI) partners to accelerate the country's ongoing initiatives for EI strengthening, introduction of a second dose of inactivated poliovirus vaccine (IPV) to increase protection against paralysis, and improving nOPV2 SIA coverage.

Global oral poliovirus vaccine stockpile management as an essential preparedness and response mechanism for type 2 poliovirus outbreaks following global oral poliovirus vaccine type 2 withdrawal.

Following the global declaration of indigenous wild poliovirus type 2 eradication in 2015, the world switched to oral polio vaccine (OPV) that removed the type 2 component. This 'switch' included the widespread introduction of inactivated poliovirus vaccine and the creation of a stockpile of monovalent type 2 OPV (mOPV2) to respond to potential polio virus Type 2 (PV2) outbreaks and events. With subsequent detection of outbreaks of circulating vaccine-derived poliovirus type 2 (cVDPV2), it was necessary to use this stockpile for outbreak response. Not only were more outbreaks detected than anticipated in the first few years after the switch, but the number of supplemental immunization activities (SIAs) used to stop transmission was often high, and in many cases did not stop wider transmission. Use of mOPV type 2 led in some locations to the emergence of new outbreaks that required further use of the vaccine from the stockpile. In the following years, stockpile management became a critical element of the cVDPV2 outbreak response strategy and continued to evolve to include trivalent OPV and genetically stabilized 'novel OPV type 2' vaccines in the stockpile. An overview of this process and its evolution is presented to highlight several of these management challenges. The unpredictable vaccine demand, fixed production and procurement timelines, resource requirements, and multiple vaccine types contributes to the complexity of assuring appropriate vaccine availability for this critical programmatic need to stop outbreaks.

Concurrent outbreaks of circulating vaccine-derived poliovirus types 1 and 2 affecting the Republic of the Philippines and Malaysia, 2019-2021.

Concurrent outbreaks of circulating vaccine-derived poliovirus serotypes 1 and 2 (cVDPV1, cVDPV2) were confirmed in the Republic of the Philippines in September 2019 and were subsequently confirmed in Malaysia by early 2020. There is continuous population subgroup movement in specific geographies between the two countries. Outbreak response efforts focused on sequential supplemental immunization activities with monovalent Sabin strain oral poliovirus vaccine type 2 (mOPV2) and bivalent oral poliovirus vaccines (bOPV, containing Sabin strain types 1 and 3) as well as activities to enhance poliovirus surveillance sensitivity to detect virus circulation. A total of six cVDPV1 cases, 13 cVDPV2 cases, and one immunodeficiency-associated vaccine-derived poliovirus type 2 case were detected, and there were 35 cVDPV1 and 31 cVDPV2 isolates from environmental surveillance sewage collection sites. No further cVDPV1 or cVDPV2 have been detected in either country since March 2020. Response efforts in both countries encountered challenges, particularly those caused by the global COVID-19 pandemic. Important lessons were identified and could be useful for other countries that experience outbreaks of concurrent cVDPV serotypes.

Long-term measles antibody profiles following different vaccine schedules in China, a longitudinal study

Characterizing the long-term kinetics of maternally derived and vaccine-induced measles immunity is critical for informing measles immunization strategies moving forward. Based on two prospective cohorts of children in China, we estimate that maternally derived immunity against measles persists for 2.4 months. Following two-dose series of measles-containing vaccine (MCV) at 8 and 18 months of age, the immune protection against measles is not lifelong, and antibody concentrations are extrapolated to fall below the protective threshold of 200 mIU/ml at 14.3 years. A catch-up MCV dose in addition to the routine doses between 8 months and 5 years reduce the cumulative incidence of seroreversion by 79.3–88.7% by the age of 6 years. Our findings also support a good immune response after the first MCV vaccination at 8 months. These findings, coupled with the effectiveness of a catch-up dose in addition to the routine doses, could be instrumental to relevant stakeholders when planning routine immunization schedules and supplemental immunization activities.

Determinants of parental knowledge and attitude towards poliomyelitis and its immunization in Sialkot city: a mix method study

<p><strong>Background and Objectives</strong>: Poliomyelitis still remains a significant public health concern in developing countries though it has been eradicated from most of the world. Illiteracy, cultural constraints, and skepticism of the general public regarding vaccination are considered major impediments to its successful eradication from developing countries. In this study, the authors aimed to evaluate parental knowledge and attitudes about poliomyelitis and its immunization in a local population as well as to elucidate the determinants and barriers relating to the immunization process.</p>
 <p><strong>Methods: </strong>This mixed-method study was conducted on 350 consenting parents who accompanied their children under 5 years of age at the pediatric outdoors of a tertiary care hospital in Sialkot, Pakistan. Parents of only those children were included for the study who had failed to receive a polio dose during the last two supplementary immunization activities The parents were interviewed on a pre-tested, semi structured questionnaire. Statistical Package for the Social Sciences was used for statistical analysis considering p-value <0.05 as significant.</p>
 <p><strong>Results:</strong> Among 350 parents, 91.7% lacked knowledge about polio vaccination and 82% reported a negative attitude towards the disease and its immunization. A total of 11.4% of subjects completely refused to get their child vaccinated. The socioeconomic status, religious myths, level of literacy, and occupation of the parents significantly influenced their level of knowledge and attitude toward the disease and its vaccination (p < 0.05).</p>
 <p><strong>Conclusion:</strong> Poor knowledge and negative attitudes of parents towards poliomyelitis vaccination were observed. Fear of side effects and religious beliefs were identified as the most common barriers to immunization toward achieving polio eradication.</p>

Challenges Addressing Inequalities in Measles Vaccine Coverage in Zambia through a Measles-Rubella Supplementary Immunization Activity during the COVID-19 Pandemic.

Measles-rubella supplementary immunization activities (MR-SIAs) are conducted to address inequalities in coverage and fill population immunity gaps when routine immunization services fail to reach all children with two doses of a measles-containing vaccine (MCV). We used data from a post-campaign coverage survey in Zambia to measure the proportion of measles zero-dose and under-immunized children who were reached by the 2020 MR-SIA and identified reasons associated with persistent inequalities following the MR-SIA. Children between 9 and 59 months were enrolled in a nationally representative, cross-sectional, multistage stratified cluster survey in October 2021 to estimate vaccination coverage during the November 2020 MR-SIA. Vaccination status was determined by immunization card or through caregivers' recall. MR-SIA coverage and the proportion of measles zero-dose and under-immunized children reached by MR-SIA were estimated. Log-binomial models were used to assess risk factors for missing the MR-SIA dose. Overall, 4640 children were enrolled in the nationwide coverage survey. Only 68.6% (95% CI: 66.7%, 70.6%) received MCV during the MR-SIA. The MR-SIA provided MCV1 to 4.2% (95% CI: 0.9%, 4.6%) and MCV2 to 6.3% (95% CI: 5.6%, 7.1%) of enrolled children, but 58.1% (95% CI: 59.8%, 62.8%) of children receiving the MR-SIA dose had received at least two prior MCV doses. Furthermore, 27.8% of measles zero-dose children were vaccinated through the MR-SIA. The MR-SIA reduced the proportion of measles zero-dose children from 15.1% (95% CI: 13.6%, 16.7%) to 10.9% (95% CI: 9.7%, 12.3%). Zero-dose and under-immunized children were more likely to miss MR-SIA doses (prevalence ratio (PR): 2.81; 95% CI: 1.80, 4.41 and 2.22; 95% CI: 1.21 and 4.07) compared to fully vaccinated children. The MR-SIA reached more under-immunized children with MCV2 than measles zero-dose children with MCV1. However, improvement is needed to reach the remaining measles zero-dose children after SIA. One possible solution to address the inequalities in vaccination is to transition from nationwide non-selective SIAs to more targeted and selective strategies.

Immunity Against Measles in Urban Refugee Children, Adolescents, and Young Adults in Eastleigh, Kenya

Background: Kenya has made progress towards the elimination of measles through routine and supplementary immunisation activities; however, sporadic outbreaks still occur. Studies on measles seroprevalence in Kenya are few and extensive analysis of refugee and migrant populations’ immunity against measles is lacking. This cross-sectional study aimed at assessing the presence of immunity against measles in children, adolescents and young adults living in the high urban refugee area of Eastleigh Nairobi, Kenya. Method: A total of 384 samples serum samples were collected from consenting respondents and tested for measles IgG antibodies. Syncytium Inhibition Assay, a neutralisation assay was used to determine functionality. The establishment of herd immunity was calculated using the Plans- Rubio formulae. Results: Seropositive rate for all respondents were 84.38%, while equivocal and negative were 4.95% and 10.68%, respectively. None of the factors analysed was a significant predictor of positive measles antibodies. 87.76% of the total sera were neutralising, while 12.23 % were negative. There was a significant correlation between the neutralisation titres and ELISA values. Conclusion: This study highlights age-specific measles immunity gaps in an urban refugee population. Although measles antibodies are present in all age groups, none has established herd immunity. In order to avert outbreaks in the study population, it is necessary to direct immunisation interventions to increase the measles antibody prevalence to recommended levels.

English

Supplementary immunization activities campaigns provide children with an additional dose of vaccine and deliver other interventions. However, there is dearth of information on knowledge, attitude and perception of mothers of under-five towards vaccination during supplementary immunization activities. A descriptive cross-sectional study which employed multistage sampling technique was designed to fill this gap. Four wards were randomly selected from eleven wards in Ibadan North-West Local Government Area and houses were enumerated from the selected wards, systematic random sampling was used to select houses and then respondents. A semi-structured interviewer administered questionnaire was used to elicit information on three hundred and five respondents. Knowledge scores of ≤4, 5-8, and ≥ 9 were rated poor, fair and good, respectively. Attitude scores of ≤5 and >5 was rated negative and positive attitude, respectively while perception scores ≤4 and >4 were rated negative and positive perception, respectively. Data was analyzed with SPSS version 25 using descriptive statistics and Chi-square test at 5% level of significance. The mean age of respondents was 30.6±6.1years, the highest level of education for most (68.5%) was secondary school. Their mean parity and number of under-five were 2.5±1.4 and 1.2±0.4, respectively. Knowledge was generally poor, more than half (53.1%) had poor knowledge, majority (88.2%) have positive attitude while 84.6% have a positive perception. One-fourth (24.6%) and one-fifth are of the opinion that frequent vaccination will make the vaccine ineffective and overload immune system, respectively. There was generally poor knowledge of supplementary immunizations and mothers need to be educated on the importance. Key words: Immunization, supplementary immunization activities, mothers of under-five, vaccination, Nigeria.

Analysis of a Sabin-Strain Inactivated Poliovirus Vaccine Response to a Circulating Type 2 Vaccine-Derived Poliovirus Event in Sichuan Province, China 2019-2021

The Sabin-strain inactivated poliovirus vaccine (IPV) may be a tool for polio outbreak response in certain situations. To investigate the response to a type 2 vaccine-derived poliovirus (VDPV2) outbreak. This case series was conducted in China after a VDPV2 was detected in stool specimens from a child with acute flaccid paralysis (AFP) in Sichuan Province in 2019, 3 years after the global withdrawal of live, attenuated type 2 oral poliovirus vaccine (OPV). Investigation followed National Health Commission and World Health Organization guidance and included searching hospitals for unreported AFP cases; testing stool specimens from the child, his contacts, and local children; enhanced environmental surveillance for VDPV2s in wastewater; and measuring vaccination coverage. Sabin-strain IPV campaigns were conducted in a wide geographic area. Any VDPV2 detection after completion of the supplementary immunization activities. A 28-nucleotide-change VDPV2 was isolated from a young boy. Three VDPV2s were detected in healthy children; 2 were contacts of the original child, and none had paralysis. A search of 31 million hospital records found 10 unreported AFP cases; none were polio. No type 2 polioviruses were found in wastewater. Prior to the event, polio vaccine coverage was 65% among children younger than 5 years. Sabin-strain IPV campaigns reached more than 97% of targeted children, administering 1.4 million doses. No transmission source was identified. More than 1 year of enhanced poliovirus environmental and AFP surveillance detected no additional VDPVs. These findings suggest that the circulating VPDV2 outbreak in 2019 was associated with low vaccine coverage. An investigation discovered 3 infected but otherwise healthy children and no evidence of the virus in wastewater. Following Sabin-strain IPV-only campaigns expanding from county to prefecture, the poliovirus was not detected, and the outbreak response was considered by an expert panel and the World Health Organization to have been successful. This success suggests that the Sabin-strain IPV may be a useful tool for responding to circulating VDPV2 outbreaks when high-quality supplementary immunization activities can be conducted and carefully monitored in settings with good sanitation.

Added value of the measles-rubella supplementary immunization activity in reaching unvaccinated and under-vaccinated children, a cross-sectional study in five Indian districts, 2018-20.

Supplementary immunization activities (SIAs) aim to interrupt measles transmission by reaching susceptible children, including children who have not received the recommended two routine doses of MCV before the SIA. However, both strategies may miss the same children if vaccine doses are highly correlated. How well SIAs reach children missed by routine immunization is a key metric in assessing the added value of SIAs. Children aged 9months to younger than 5years were enrolled in cross-sectional household serosurveys conducted in five districts in India following the 2017-2019 measles-rubella (MR) SIA. History of measles containing vaccine (MCV) through routine services or SIA was obtained from documents and verbal recall. Receipt of a first or second MCV dose during the SIA was categorized as "added value" of the SIA in reaching un- and under-vaccinated children. A total of 1,675 children were enrolled in these post-SIA surveys. The percentage of children receiving a 1st or 2nd dose through the SIA ranged from 12.8% in Thiruvananthapuram District to 48.6% in Dibrugarh District. Although the number of zero-dose children prior to the SIA was small in most sites, the proportion reached by the SIA ranged from 45.8% in Thiruvananthapuram District to 94.9% in Dibrugarh District. Fewer than 7% of children remained measles zero-dose after the MR SIA (range: 1.1-6.4%) compared to up to 28% before the SIA (range: 7.3-28.1%). We demonstrated the MR SIA provided considerable added value in terms of measles vaccination coverage, although there was variability across districts due to differences in routine and SIA coverage, and which children were reached by the SIA. Metrics evaluating the added value of an SIA can help to inform the design of vaccination strategies to better reach zero-dose or undervaccinated children.

Providing information for decision-making in the Nigerian Polio Eradication Program, 2016-2020.

Nigeria made a coordinated effort to be certified by the World Health Organization's African Region for interrupting endemic transmission of wild poliovirus type-1 (WPV1) in August 2020 as a response to the resurgence of WPV1 cases in August 2016 after going two years without a case. The NEOC Data Working Group (DWG) was instrumental in providing quality and timely surveillance and campaign information for decision-making in order to interrupt WPV1 transmission and provide data toward documentation of its elimination for regional certification. The polio pre-campaign dashboard was used to assess the level of preparedness for Oral Poliovirus Vaccine (OPV) polio supplementary immunization activities (SIA) at three weeks, two weeks, one week, and three days to the start of each campaign implemented during 2016-2020. The administrative tally sheet, independent monitoring survey, and Lot Quality Assurance Sampling (LQAS) survey data collected and shared from the implementation level were analyzed by the EOC DWG to provide information by person, place, and time. Using a 90% threshold in LQAS surveys defining quality SIAs, the proportion of Local Government Areas (LGAs) in Nigeria's states in which post-SIA LQAS surveys were conducted that met this threshold were assessed over time. The highest level of preparedness attained by 3 days to a polio campaign during August 2016-February 2020 was 95% and the lowest attained was 77%. The admin, independent monitoring, and LQAS data analysis results were given to EOC working groups for assessing the performance and quality of each campaign. Twenty-twenty five percent of LGAs that failed LQAS were identified for repeat vaccination. Further, acute flaccid paralysis and environmental surveillance data and laboratory results were analyzed and shared with NEOC and partners. The government and partners used the information generated by the Data Working Group to take evidence-based action including determining the scope of the polio campaign, intensification of surveillance and routine immunization activities, and special intervention activities. On average, 12% of the 774 LGAs were identified as polio high risk LGAs for intervention using selected surveillance, routine immunization (RI), SIAs, and other relevant data sets. National Emergency Operation Centre Data Working Group provided quality and timely information that supported decision-making processes for the polio program in Nigeria. The quality and timely information enabled the NEOC to make evidence-based and timely decisions that contributed to gap identification and decision-making.

Assessment of open data kit mobile technology adoption to enhance reporting of supportive supervision conducted for oral poliovirus vaccine supplementary immunization activities in Nigeria, March 2017-February 2020.

in Nigeria, supportive supervision of Supplementary Immunization Activities (SIA) is a quality improvement strategy for providing support to vaccination teams administering the poliovirus vaccines to children under 5 years of age. Supervision activities were initially reported in paper forms. This had significant limitations, which led to Open Data Kit (ODK) technology being adopted in March 2017. A review was conducted to assess the impact of ODK for supervision reporting in place of paper forms. issues with paper-based reporting and the benefits of ODK were recounted. We determined the average utilization of ODK per polio SIA rounds and assessed the supervision coverage over time based on the proportion of local government areas with ODK geolocation data per round. a total of 17 problematic issues were identified with paper-based reporting, and ODK addressed all the issues. Open Data Kit-based supervision reports increased from 3,125 in March 2017 to 51,060 in February 2020. Average ODK submissions for national rounds increased from 84 in March 2017 to 459 in February 2020 and for sub-national rounds increased from 533 in July 2017 to 1,596 in October 2019. Supportive supervision coverage improved from 42.5% in March 2017 to 97% in February 2020. the use of digital technologies in public health has comparative advantages over paper forms, and the adoption of ODK for supervision reporting during polio SIAs in Nigeria experienced the advantages. The visibility and coverage of supportive supervision improved, consequentially contributing to the improved quality of polio SIAs.

Sustainable Development Goal Halftime Project: Benefit-Cost Analysis Using Methods from the Decade of Vaccine Economics Model

AbstractIn 2023, the world will be at “halftime” with respect to the sustainable development goals (SDGs). This midline acts as an important milestone to review the progress of the SDGs and develop policies based on the most effective interventions. To estimate the remaining resources needed to achieve SDG targets for vaccines from 2023 to 2030 as well the resulting economic benefits, in this analysis, the incremental economic benefit-cost ratio (BCR) for immunization programs in 80 low- and middle-income countries targeted by the Global Vaccine Action Plan from 2023 to 2030 is calculated. Of these 80 countries, 27 are classified as low-income countries and 53 are classified as lower-middle-income countries (LMICs). The economic evaluation covers 9 vaccines employed against 10 antigens and delivered through both routine immunization programs and supplemental immunization activities. The vaccines covered in the analysis include pentavalent vaccine, human papillomavirus vaccine, Japanese encephalitis vaccine, measles vaccine, measles-rubella vaccine, meningococcal conjugate A vaccine, pneumococcal conjugate vaccine, rotavirus vaccine, and yellow fever vaccine, and correspond to the vaccines covered in the return-on-investment estimates presented in Sim et al., which covered 94 LMICs from 2011 to 2030. For these countries, we estimate program costs from the health system perspective, including vaccine costs such as costs to procure vaccines, which incorporate injection supplies and freight; and immunization delivery costs, which include nonvaccine commodity costs to deliver immunizations to target populations and incorporate labor, cold chain and storage, transportation, facilities, training, surveillance, and wastage. Economic benefits are calculated using a value of statistical life year (VSLY) approach applied to modeled cases, and deaths averted are converted into averted years of life lost using life expectancy data. BCRs are presented as the final output that compares incremental costs and benefits from the baseline of 2022 levels, assuming diminishing returns to scale. Overall, for this period, we estimate total costs of US$ 7,581,837,329.08 with VSLY benefits of US$ 762,172,371,553.54, resulting in a BCR of 100.53.

Field Monitoring of the Implementation of Polio Supplementary Immunization Activities Following Circulating Vaccine-Derived Polio Virus Type 2 (CVDPV2) Outbreak in Aceh, Indonesia

Field Monitoring of the Implementation of Polio Supplementary Immunization Activities Following Circulating Vaccine-Derived Polio Virus Type 2 (CVDPV2) Outbreak in Aceh, Indonesia