Measles and Rubella Elimination Regional Monitoring and Re-Verification Commission

To be verified as measles-free, a country must provide comprehensive evidence to the RVC demonstrating:

• High vaccination coverage, both through routine immunization and targeted campaigns.
• Interruption of endemic transmission for at least 12 consecutive months, confirmed by epidemiological and laboratory data.
• Robust surveillance systems capable of detecting and investigating suspected cases quickly, supported by molecular epidemiology (e.g., genotyping).
• Effective outbreak response, including rapid deployment of trained teams and implementation of selective or mass vaccination strategies, considering the epidemiologic situation.
• Submission of detailed documentation to the RVC, including surveillance quality assessments, outbreak investigation results, and immunization data.

The RVC reviews this evidence in collaboration with each country’s National Commission for the Sustainability of Elimination and sends a formal report to the Director of PAHO, who assess it and formally communicates the decision publicly and to the respective country.

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The reestablishment of endemic transmission of measles and/or rubella results in the loss of elimination status for these diseases.

In accordance with the Regional Framework for Monitoring and Revalidation of Measles, Rubella, and Congenital Rubella Syndrome Elimination in the Region of the Americas, the RVC applies uniform criteria for all countries in the Region. According to these criteria, endemic transmission of measles is considered to have been reestablished when epidemiological and laboratory evidence indicates that there is a chain of transmission of a viral strain (identical genotype and lineage) that has been maintained uninterrupted for 12 months or more within a defined geographical area (region or country).

It is important to note that the date used to assess whether endemic transmission has been reestablished is not modified or extended. What may vary is the timing of the RVC's meeting with each country to review the evidence presented. This timing depends on the time required for the country or countries to prepare their documentation and for the Commission to complete its review and validation, in accordance with the established criteria. Based on the results of the meeting, the RVC prepares a report with recommendations for the director of PAHO, who, after evaluating the Commission's recommendation, will officially communicate the country's elimination status classification.

The Regional Framework for Monitoring and Re-Verification of Measles, Rubella, and Congenital Rubella Syndrome Elimination does not require a determination to be issued on a specific date, but rather to identify the moment when the epidemiological criteria have been met.

In some cases, the meeting and announcement on the reinstatement of endemic transmission may occur shortly after the 12-month period has been reached, especially if it coincides with a scheduled annual meeting of the RVC and if the country or countries submit their report in a timely manner. In other cases, more time is allowed to prepare more comprehensive reports, which may include additional analyses—such as complete genomic sequencing—to supplement epidemiological and laboratory evidence.

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Losing measles elimination status means that endemic transmission has been re-established, often due to gaps in vaccination, surveillance, or outbreak response. While there are no formal penalties, the consequences can be serious:

• Increased risk of measles or rubella outbreaks, especially among vulnerable populations.
• Greater pressure on national health systems.
• Reversal of public health gains.

To regain elimination status, the country must:

1. Interrupt endemic transmission for at least 12 months.
2. Submit a corrective action plan to PAHO, aligned with the regional framework.
3. Strengthen immunization, surveillance, and outbreak response systems.

For example, after reestablishing endemic measles transmission in 2019, Brazil successfully interrupted endemic transmission by mid-2022 and regained its measles-free status in 2024.

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Re-verification follows the same rigorous process as initial verification. The country must:

• Demonstrate 12 months without endemic transmission.
• Strengthen the vaccination program, surveillance performance, and outbreak response, providing comprehensive data reports on the progress achieved.
• Work with its National Sustainability Commission to compile and submit evidence to the RVC.

The RVC then reviews the submission and determines whether elimination status can be reinstated.

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• In 1994, the countries in the region adopted the resolution to eliminate measles. Last endemic case of the pre-elimination period was reported in Venezuela in 2002.
• In 2003, the countries in the region adopted the resolution to eliminate rubella and congenital rubella syndrome (CRS). Last endemic cases of rubella and CRS in the pre-elimination period were reported in 2009 in Argentina and Brazil, respectively.
• In 2015, the Region of the Americas became the first to achieve endemic rubella and CRS elimination.
• In 2016, the Americas Region officially achieved measles elimination after being declared free of endemic measles. To date, it is the only region in the world to have achieved this milestone. However, sustaining this achievement requires a significant effort from every country in the region, given the high transmissibility of the disease.  
• In 2018, Venezuela lost its measles elimination status due to a prolonged outbreak that began in 2017. After interrupting the outbreak and maintaining no endemic transmission for approximately four years, it was reverified as free of measles in 2023.  
• In 2019, Brazil lost its measles elimination status. Following extensive vaccination, surveillance, and rapid response efforts, the country was reverified as measles-free in November 2024. Brazil maintained interruption of endemic transmission for more than two years before the country declared again as measles free, as the last endemic case was identified in June 2022. In total, approximately five years elapsed between the loss and reinstatement of measles-free status.
• In 2024, the region was reverified as free of endemic measles thanks to the coordinated efforts of all member countries to improve epidemiological surveillance, rapid response, and vaccination against the disease.  
• In October 2024, Canada reported the start of a new measles outbreak in New Brunswick. Since then, the outbreak has spread to multiple provinces including Manitoba, Ontario, Quebec, Alberta, British Columbia, and Saskatchewan. There are over 5,000 confirmed cases reported nationwide as of mid-October and is considered still active.  
• In January 2025, the US reported the start of a measles outbreak that is also considered still active, with over 1,600 confirmed cases as of mid-October.  
• In February 2025, Mexico reported the start of an ongoing measles outbreak, with over 4,000 confirmed cases as of the same date.
• In November 2025, PAHO announced that the Americas had lost its status as a region free of endemic measles transmission, following the meeting of the RVC. The report indicates that endemic measles transmission has been reestablished in Canada, where the virus has been circulating for at least 12 months.

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• Jon Andrus (United States-Chair)
• Angela Gentile (Argentina)
• Fernando de la Hoz (Colombia)
• Herminio Hernández (Perú)
• José Ignacio Santos (México)
• Marilda Siqueira (Brazil)
• Susan Reef (United States)
• Tracy Evans-Gilbert (Jamaica)

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