Pan American Health Organization

Health Status of the Population

Vaccine-preventable Diseases

This section presents the progress made by each strategic line of action of the Regional Plan of Action on Immunization (2015–2016).

Strategic line of action 1: Sustain the achievements

Polio

In 1991, the last case of polio was reported in Latin America and the Caribbean (LAC). The disease reemerged briefly in 2000 when 20 vaccine-associated cases were reported in Haiti and the Dominican Republic, but no other cases have been reported since 1991. In 1994, the Region of the Americas was certified as being free of the indigenous wild poliovirus. In 2013, the World Health Assembly adopted the targets, goals, and timelines of the Polio Eradication and Endgame Strategic Plan 2013-2018 (). The plan called for withdrawing all oral polio vaccines (OPV), starting with the type 2 component of the trivalent vaccine. The strategic advisory group of experts (SAGE) on immunization and the technical advisory group (TAG) on vaccine-preventable diseases recommended that prior to removing the type 2 component of OPV, countries introduce at least one dose of the inactivated poliovirus vaccine (IPV). Between February 2015 and April 2016, all 32 countries in the Region that previously used only OPV introduced at least one dose of IPV into their routine immunization schedule, and between 17 April and 1 May 2016, 36 countries and territories in the Americas switched from the trivalent oral polio vaccine (tOPV) to the bivalent vaccine (bOPV), as part of a globally coordinated effort. The Regional Containment Committee and PAHO Secretariat received reports on advances in poliovirus containment following standardized methodology from 16 countries and the Caribbean subregion (including 13 countries, 6 United Kingdom territories, and 3 associate members) (). All countries providing reports demonstrated a commitment to containment and have progressed significantly with phase I in their containment activities. Some of the best practices identified required strong political leadership, multisectoral engagement, technical commitment, and collaboration with and active involvement of the national certification committee in reviewing, analyzing, and submitting reports.

Rubella and congenital rubella syndrome

On 22-23 April 2015, the International Expert Committee (IEC) for regional verification for eliminating measles and rubella in the Americas reviewed the epidemiological information presented by Member States and determined that the Region had interrupted the endemic transmission of rubella. The last confirmed case of endemic rubella was reported on 3 February 2009 in Argentina, and the last confirmed case of congenital rubella syndrome was in a baby born 26 August 2009 in Brazil. Genotypes 2B and D8 were identified in the last endemic rubella outbreaks in Argentina and Brazil ().

Measles

In 2002, the Region met the goal of eliminating circulation of the endemic measles virus. The secular trend of measles in the post-elimination period between 2003 and 2010 was relatively stable, with an annual average of 153 cases either imported or linked to imported cases. However, between 2011 and 2015, major outbreaks in Brazil, Canada, Ecuador, and the United States resulted in 8 to 12 times more reported cases than in the preceding period. Nevertheless, the highest Regional rate, 1.7 cases per million inhabitants in 2014, is lower than 5 cases per 1 million inhabitants—the milestone set by the World Health Assembly in 2010 for progress toward the goal of worldwide elimination ().

The IEC declared that endemic measles transmission had reemerged exclusively in Brazil, after an outbreak that lasted for more than 27 months. Brazil considered endemic measles transmission to have been interrupted as of 6 July 2015—following a rash onset of the last case—and presented the IEC with evidence of the end of the outbreak in December 2015. In July 2016, Brazil presented to the IEC the definitive proof of the absence of endemic transmission of the virus ().

Declaration of the Americas as free of measles

Between April and June 2016, all the ministries of health of Member States submitted their national sustainability reports, with evidence that they have maintained the interruption of endemic transmission of this disease in their territories. During the 55th Directing Council of the Pan American Health Organization/World Health Organization (PAHO/WHO), the Region of the Americas was declared free of measles. This achievement culminated a 22-year effort involving mass vaccination against measles, mumps, and rubella throughout the Americas ().

Perinatal hepatitis B virus (HBV)

As of 2016, 22 of 51 countries and territories had introduced a universal birth dose vaccination policy; 14 countries and territories vaccinate only infants born to HBsAg-positive mothers as part of their efforts to control HBV perinatal transmission. In 2015, Regional coverage in the Americas for the third dose of hepatitis B vaccine (pentavalent) was 89% among children younger than 1 year, and birth dose coverage was 73% for the entire LAC cohort (including countries without a vaccination policy for newborns) ().

Influenza

As of 2015, 40 of the 51 countries/territories in the Americas had defined policies for seasonal influenza vaccination. Twenty-five countries/territories have expanded target groups. In accordance with the SAGE and TAG recommendations, 29 countries/territories currently target pregnant women as the highest-priority group for vaccination; in 2008, only 7 countries/territories did. Among 23 countries reporting coverage data in 2015, those vaccinated included 75% of adults 60 or older, 45% of children 6 to 23 months old, 32% of children 2 to 5 years old, 59% of pregnant women, 78% of health care workers, and 90% of individuals with chronic conditions ().

Strategic line of action 2: Address the unfinished agenda in order to prevent and control vaccine-preventable diseases

According to data provided to PAHO by countries on the immunization joint reporting forms for 2015, coverage in the Americas for DPT3 and for a third dose of polio vaccine in children younger than 1 year was 91% and 92%, respectively; the vaccination coverage for measles and rubella in children at 1 year of age was 93%. In 2015, 19 countries and territories reported national average coverage of at least 95% for DPT3 in children younger than 1 year—the same number as in 2014. However, immunization coverage still reflects inequalities between countries and within each country: in 2015, 56% of LAC municipalities (8,456 of nearly 15,000) reported DPT3 vaccination coverage below 95% ().

Dropout rate

In the Americas, 91% of children younger than 1 year were vaccinated with DPT3 and 96% received DPT1, with an overall dropout rate of 6%. In countries such as the Dominican Republic, Guatemala, Mexico, Panama, and Venezuela, the dropout rate was greater than 10% (). The dropout rate is a measure of the strength of a health and immunization system and demonstrates its potential to reach children with the third dose in a series. Countries should define specific strategies to address factors that contribute to incomplete infant vaccination schedules.

Neonatal tetanus (NNT)

In the Region, only Haiti has failed to reach the NNT elimination goal. The country has advanced substantially toward NNT elimination, however, and it put in place activities designed to achieve this goal by the end of 2015 (with measurement still in progress). Since 2013, in addition to vaccinating pregnant women during routine immunization activities, three rounds of tetanus and diphtheria (Td) vaccination campaigns were conducted. As a result of these interventions, in 2015, 94% of the communities reached Td2 coverage greater than or equal to 80% in women of childbearing age, and, during 2015, no municipality reported one or more NNT case per 1,000 live births ().

Strategic line of action 3: Tackle new challenges in the introduction of vaccines and assess their impact

Currently, 34 countries and territories have introduced pneumococcal conjugate vaccine (PCV) and 20 have introduced rotavirus vaccine (RV) into their routine vaccination schedule. In 2015, Argentina introduced the rotavirus monovalent vaccine and plans to introduce meningococcal conjugate quadrivalent vaccine in 2017. Countries and territories in the Region have increasingly incorporated data on the impact and cost-effectiveness of vaccines into their decision-making processes for adopting new vaccines. To aid decision-making, since 2016, results from 29 nationally reported cost-effectiveness analyses (11 for PCV, 4 for RV, 14 for HPV, plus 2 EPI costing and financial analyses) have been presented to national authorities, including National Immunization Technical Advisory Groups (NITAGs) and high-level authorities at ministries of health (). The process of conducting cost-effectiveness analysis and modeled vaccine-impact analyses before introducing a new vaccine has helped countries systematically review a number of evidence criteria for new vaccine introduction—including the disease burden, costs of existing vaccine-preventable disease control and treatment, vaccine efficacy, and vaccine type disease circulating in the country. In 2016, PAHO’s ProVac expanded its existing toolkit to address other vaccine policy questions. Support for dengue vaccine introductions will be urgently needed in the near term.

Strategic line of action 4: Strengthen the health services for effective vaccine administration

PAHO Revolving Fund for purchasing vaccinations

The PAHO Revolving Fund continues to support 41 countries and 4 territories in the Region for access to quality vaccines and related immunization supplies procured with national funds. The Revolving Fund contributes to the financial sustainability of the immunization programs, ensuring countries and territories access to low and steady prices of vaccines. In 2016, more countries, including Honduras and Guyana, began fully funding vaccines that were initially introduced with support from Gavi, the Vaccine Alliance. In addition, as part of the ongoing efforts to increase access to lower prices for participating countries, the Secretariat concluded negotiations with the two multinational manufacturers of PCV in the marketplace, achieving price reductions of approximately 12% in 2016 compared with 2015, representing savings of over US$ 10 million annually for the group of countries procuring this vaccine. The PCV vaccine represents more than 60% of the total vaccine procurement budget of countries in the Region.

Data quality

Data quality is a constant challenge in ensuring reliable, high-quality vaccination coverage. The countries of the Americas have strongly committed to promote activities related to data quality, and have incorporated that into their plans of action at the national level, as well as monitoring at the subnational level. During 2014–2016, five countries conducted evaluations at the national and subnational level (Ecuador, Haiti, Honduras, Mexico, and Peru).

The countries of the Region have also been working toward implementing electronic immunization registry (EIR) systems with the goal of improving data quality and program performance. An EIR is a useful tool for monitoring individualized vaccinations; it defines vaccination strategies through targeted reminders, supports vaccination campaigns, and provides timely access to information, among other tasks. Five countries (Argentina, Chile, Grenada, Panama, and Uruguay) currently use EIR systems at the national level. The other countries in the Region are implementing EIR systems at the subnational level, developing their EIRs, or strengthening their paper-based information systems ().

Cold chain operations

Countries of the Region have focused on expanding cold chain operations and strengthening the supply chain and logistics operations for the introduction of new vaccines. During 2014-2016, effective vaccine management assessments were conducted in Honduras (97% score), Nicaragua (93% score), Guyana (83% score), and Haiti (55% score). The minimum score established by effective vaccine management is 80%, so the results reported in the aforementioned countries represent a significant achievement.

In 2015, countries and territories throughout the Western Hemisphere reached approximately 60 million children and adults during the 14th annual Vaccination Week in the Americas, delivering vaccines for diseases including rubella, measles, diphtheria, mumps, whooping cough, neonatal tetanus, influenza, yellow fever, bacterial pneumonia, human papillomavirus, and diarrhea caused by rotavirus, among others (). Integrated with other health interventions, Vaccination Week in the Americas is an opportunity to vaccinate vulnerable or hard-to-reach populations and promote cross-border coordination; it also keeps vaccination on the countries’ political and social agenda. Its success has come to serve as a model for implementing simultaneous sister initiatives in other WHO regions, and it helped inspire the establishment of World Vaccination Week in 2012.

In 2015, all Member States claimed immunization as a priority intervention, and on average, health authorities mobilized 99% of all vaccine financing from domestic resources. A total of 26 countries in the Americas have active legal frameworks to protect immunization as a public good. PAHO is working with a number of countries that are revising their legal frameworks for health and sanitary codes to include the right to immunization. Additionally, several countries have demonstrated strong commitment to immunization by continuing to strengthen NITAGs, which serve as objective and transparent advisory bodies to national health authorities. As of 2016, 23 of the 35 PAHO Member States reported an active NITAG, and 16 of the committees meet the PAHO/WHO criteria for good operation ().

References

1. World Health Organization. Polio global eradication initiative. Polio eradication & endgame strategic plan 2013-2018. Geneva: WHO; 2013. Available from: http://polioeradication.org/wp-content/uploads/2016/07/PEESP_EN_A4.pdf.

2. Pan American Health Organization. Update on implementation of TAG recommendations on the polio eradication and endgame strategic plan 2013-2018. In: Vaccination: your best shot! 2014 Vaccination Week in the Americas. Final report of the XXII Technical Advisory Group (TAG) Meeting on Vaccine-preventable Diseases of the Pan American Health Organization, Washington, D.C., USA, 1-2 July 2014. Washington, D.C.: PAHO; 2014. Available from: https://www.paho.org/hq/index.php?option=com_docman&task=doc_download&gid=26691&Itemid=270&lang=en.

3. Pan American Health Organization. Plan of action for maintaining measles, rubella, and congenital rubella syndrome elimination in the Region of the Americas: final report. 55th Directing Council, 68th Session of the Regional Committee of WHO for the Americas, Washington, D.C., 2016 Sept. 26-30 (document CD55/INF/10, Rev. 1). Available from: https://www.paho.org/hq/index.php?option=com_docman&task=doc_download&gid=35681&Itemid=270&lang=en.

4. Pan American Health Organization. Feasibility of perinatal hepatitis B elimination in the Americas. In: Final report of the XXIV Technical Advisory Group (TAG) Meeting on Vaccine-preventable Diseases of the Pan American Health Organization. Ad-hoc Virtual Meeting, 13 May, 2016. Washington, D.C.: PAHO; 2016. Available from: https://www.paho.org/hq/index.php?option=com_docman&task=doc_download&gid=35019&Itemid=270&lang=en.

5. Pan American Health Organization. Technical Advisory Group (TAG) Meeting on Vaccine-preventable Diseases. Status of influenza vaccination in the Americas and formation of the network for evaluation of influenza vaccine effectiveness-REVELAC-i. In: Vaccination: your best shot! 2014 Vaccination Week in the Americas. Final report of the XXII Technical Advisory Group (TAG) Meeting on Vaccine-preventable Diseases of the Pan American Health Organization, Washington, D.C., USA, 1-2 July 2014. Washington, D.C.: PAHO; 2014. Available from: https://www.paho.org/hq/index.php?option=com_docman&task=doc_download&gid=26691&Itemid=270&lang=en.

6. Pan American Health Organization. Immunization in the Americas: 2016 summary. Washington, D.C.: PAHO; 2016. Available from: https://www.paho.org/hq/index.php?option=com_docman&task=doc_view&Itemid=270&gid=36288&lang=en.

7. Pan American Health Organization. Progress toward regional neonatal tetanus elimination. In: Final report of the XXIII Technical Advisory Group (TAG) Meeting on Vaccine-preventable Diseases of the Pan American Health Organization, held in Varadero, Cuba, 1-3 July 2015. Available from: https://www.paho.org/hq/index.php?option=com_docman&task=doc_download&gid=31233&Itemid=270&lang=en.

8. Jauregui B, Janusz CB, Clark A, Sinha A, Felix Garcia AG, Resch S, et al. ProVac global initiative: a vision shaped by ten years of supporting evidence-based policy decisions. Vaccine 2015;33(S1):A21-A27.

9. Pan American Health Organization. Vaccination Week in the Americas 2015. Executive summary. Boost your power. Available from: https://www.paho.org/vwa/wp-content/uploads/2015/11/Executive-Summary-VWA-2015.pdf.

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Reference/Note:

Regional Office for the Americas of the World Health Organization
525 Twenty-third Street, N.W., Washington, D.C. 20037, United States of America