WHO Prequalification Signals Shift in Vaccine Supply Strategy

The WHO’s prequalification of an additional novel oral polio vaccine type 2 expands global outbreak response capacity and reinforces diversified vaccine manufacturing. The move aligns with Mexico’s efforts to strengthen immunization coverage and scale domestic mRNA production through partnerships involving Moderna, BIRMEX and Laboratorios Liomont, with implications for pharmaceutical manufacturing, public procurement and health supply chain oversight

The World Health Organization (WHO) has prequalified an additional novel oral polio vaccine type 2 (nOPV2), expanding global supply at a time when countries are reinforcing immunization systems and outbreak response capacity. The designation strengthens procurement channels through United Nations agencies and supports efforts to contain vaccine-derived poliovirus outbreaks. The move coincides with broader public health and manufacturing reforms in Mexico aimed at improving vaccine access, domestic production and supply chain oversight.

“Vaccines are also bringing us closer to the eradication of polio, with 41 cases of wild polio reported last year from just 24 districts in Pakistan and Afghanistan, down from 99 cases in 49 districts in 2024,” said Tedros Adhanom Ghebreyesus, Director-General, WHO, during the organization’s 158th Executive Board session. He said sustained immunization coverage remains essential to prevent reversals in disease control gains.

Expanding Global Vaccine Supply

WHO’s prequalification confirms that the newly listed nOPV2 meets international standards of quality, safety and efficacy and allows procurement through agencies including UNICEF. The vaccine is manufactured by Biological E. Limited using in-house bulk production following a technology transfer from PT Bio Farma. The listing builds on previous approvals for versions produced by PT Bio Farma and for fill-and-finish operations conducted by Biological E.

The diversification of suppliers is intended to ensure a more resilient and reliable manufacturing base for nOPV2. The vaccine was developed to address outbreaks of circulating vaccine-derived poliovirus type 2 (cVDPV2), which can emerge in under-immunized populations. Compared with the traditional monovalent oral polio vaccine type 2, nOPV2 is engineered for greater genetic stability, reducing the risk of seeding new outbreaks while maintaining effectiveness in interrupting virus transmission.

nOPV2 is authorized for emergency use in response to type 2 outbreaks, when requested by the Global Polio Eradication Initiative or WHO. Since its deployment, it has been used in outbreak campaigns reaching hundreds of millions of children. Operational features include 20-dose and 50-dose vial presentations, a 24-month shelf life at minus 20 degrees Celsius, and storage flexibility for up to six months at standard refrigeration temperatures. Under the WHO’s multi-dose vial policy, opened vials may be used for up to 28 days, supporting efficient use during mass campaigns.

Measles Resurgence Pressures Immunization Systems

The expansion of polio vaccine supply occurs amid renewed measles transmission across the Americas. In November 2025, the Pan American Health Organization confirmed that the region no longer meets the criteria for measles elimination after sustained transmission in several countries, including Mexico, Canada and the United States.

Mexico recorded more than 6,400 confirmed measles cases and 24 deaths in 2025, with concentrations in Chihuahua, Mexico City, Jalisco, Guerrero, Michoacan and the State of Mexico. Children under five represented the largest share of cases, while young adults aged 20 to 40 showed lower immunity due to incomplete vaccination or missed booster doses.

Authorities have deployed over 23.5 million doses of measles-mumps-rubella and measles-rubella vaccines nationwide. In Mexico City, vaccination points were extended to Metro stations and high-traffic public transport hubs. Mauricio López, Deputy Minister of Health for Mexico City, said the strategy is designed to increase accessibility and reduce transmission risk.

Regional data show cases rising from 466 in 2024 to nearly 14,900 in 2025. First-dose coverage in the Americas reached 88% in 2024, while second-dose coverage averaged 79%, below the 95% threshold required to prevent outbreaks. Health officials cite vaccine hesitancy and disruptions linked to the COVID-19 pandemic as contributing factors.

The resurgence coincides with preparations for the 2026 FIFA World Cup, expected to attract millions of visitors to Mexico. Authorities are coordinating with PAHO and international partners to reinforce surveillance and rapid response systems during the tournament.

Mexico Strengthens Production and Supply Oversight

Parallel to intensified vaccination campaigns, Mexico is expanding domestic production and strengthening medicine supply oversight. President Claudia Sheinbaum recently announced a five-year agreement with Moderna, BIRMEX and Laboratorios Liomont to produce messenger RNA vaccines locally. The partnership includes phased technology transfer, beginning with fill-and-finish operations and progressing to full domestic manufacturing. According to the Ministry of Health, the collaboration is expected to extend beyond COVID-19 vaccines to projects targeting dengue and certain cancers.

The initiative aligns with broader efforts to reinforce pharmaceutical sovereignty and reduce exposure to external supply disruptions. Complementary measures include the Central de Mezclas facility expansion in Tlalpan and cooperation agreements with academic institutions such as the Universidad Nacional Autónoma de México to integrate research and workforce training into production systems.

At the distribution level, the Ministry of Health launched the Monitoring System for Compliance with the Supply of Health Supplies, a mandatory national platform covering IMSS, ISSSTE, IMSS-Bienestar, BIRMEX and the Ministry itself. The system collects data from domestic and international suppliers to measure fulfillment rates, identify delivery gaps and generate compliance certificates. Authorities say the tool will improve planning and accountability across public procurement channels.

The monitoring system operates alongside logistics reforms, including investments by IMSS in high-technology diagnostic equipment and distribution infrastructure. Despite reported medicine supply rates above 90% in major institutions, protests in late 2025 highlighted shortages and operational bottlenecks. Officials say real-time data tracking will help mitigate warehouse saturation and payment delays while aligning supply with rising service demand.

The WHO’s expansion of nOPV2 prequalification underscores the importance of diversified production in sustaining global eradication efforts.