Influenza

Globally, influenza detections remained low in week 33 with influenza A and B viruses detected in similar proportions.

In the southern hemisphere, influenza percent positivity was elevated (>10%) in one country in Temperate South America. Percent positivity was over 30% in one country in Oceania where a medium increase in activity was observed.

In the northern hemisphere, influenza percent positivity was elevated (>10%) in some countries in Central America and the Caribbean, Tropical South America, Western Africa, Western, Southern and South-East Asia and in single countries in Middle Africa, South West and Northern Europe and Eastern Asia. Percent positivity was over 30% in single countries in Tropical South America, Western and Eastern Africa and Southern Asia. Increases in activity were observed in some countries in Central America and the Caribbean and Southern Asia and in single countries in Tropical South America, Western, Eastern and Middle Africa, South West Europe and Western Asia.

In the zones with elevated positivity, influenza A(H3N2) was predominant in South West Europe, Eastern Africa, Eastern Asia and Oceania; influenza A(H1N1)pdm09 was predominant in Western, Southern and South-East Asia and influenza B was predominant in Tropical and Temperate South America. Influenza A and B were codominant in Central America and the Caribbean and Western Africa and influenza A(H1N1)pdm09 and influenza A(H3N2) were codominant in Middle Africa.

SARS-CoV-2

Globally, SARS-CoV-2 positivity remained stable and low across most reporting countries, with elevated positivity (>10%) reported in countries in Central America and the Caribbean and in single countries in Tropical South America, Southern and South-East Asia. Small increases in activity were observed in countries in Central America and the Caribbean, Northern Europe and in a single country in Southern Asia.

Respiratory Syncytial Virus (RSV)

RSV positivity was elevated (>10%) in a few countries in Central America and the Caribbean, Tropical and Temperate South America and in a single country in Southern Asia. Percent positivity was over 30% in a single country in Temperate South America. Small increases in activity were observed in two countries in Central America and the Caribbean. RSV and influenza activity were both elevated in single countries in Temperate South America and Southern Asia.

Severity assessment

The severity assessments here are reported from countries, areas and territories. Assessments for transmissibility can be reported based on syndromic parameters and/or influenza-specific parameters. In the southern hemisphere temperate and subtropical areas, influenza-specific transmissibility was reported as low (1) and moderate (1); transmissibility using syndromic data was reported as moderate (1). In the northern hemisphere temperate and subtropical areas, influenza-specific transmissibility was reported as below seasonal threshold (11) and low (2); transmissibility using syndromic data was reported as below seasonal threshold (8). Influenza-specific transmissibility was reported as moderate in one country in the tropical areas.

Smart pharmacovigilance

In May 2026 the Seventy-ninth World Health Assembly adopted a resolution on “Advancing smart, efficient pharmacovigilance as an essential tool for robust, sustainable, resilient and responsive health systems, for everyone, everywhere”.¹ The resolution calls on WHO Member States to strengthen and integrate systems for monitoring the safety of medicines, vaccines and other health technologies, while improving regulatory capacity and workforce development.

The Committee members welcomed the concept of smart pharmacovigilance as part of the regulatory system and recognized the need for an organized approach funded as part of the regulatory function. The Committee encouraged WHO to support Member States in implementing the resolution through practical guidance, risk-based approaches, strengthened collaboration between regulatory authorities and public health programmes, and enhanced regional cooperation – particularly for resource-limited countries.

Risk communication

The meeting reviewed a draft risk communication guidance document and a set of standard operating procedures. The tool addresses three principles of communication – namely accuracy, transparency and consistency – for addressing the public. There was broad appreciation for the proposed approach, though Committee members highlighted the value of involving regulators from different regions and levels of regulatory maturity in testing and refining the tools to ensure their relevance and usability in diverse settings.

Maternal respiratory syncytial virus vaccine (Abrysvo©)

In September 2024 the Strategic Advisory Group of Experts on Immunization (SAGE) issued a recommendation on the use of the respiratory syncytial virus (RSV) vaccine in pregnancy. In November 2024 ACSoMP and GACVS concluded that the available evidence did not establish a causal relationship between maternal respiratory syncytial virus (RSV) vaccination and preterm birth. The June 2026 meeting provided an overview of post-licensure safety data on maternal RSV vaccine (RSVpreF, Abrysvo®) and outlined safety monitoring activities for mothers and infants.

A summary by the manufacturer, Pfizer, showed that RSVpreF is well tolerated with mostly mild-to-moderate local and systemic events and no unexpected serious adverse reactions for reactogenicity. No deaths were assessed as related in a recent study in South Africa. A further Phase 3 study is planned to take place in India in 2027.

A study from the Australia Centre for Health Analytics focused on 1493 pregnancies with at least one pre-existing comorbidity – chiefly diabetes (31%) or chronic pulmonary disease (29%). In the 3% of pregnancies where Abrysvo was given with at least one hospital-recorded comorbidity prior to pregnancy, no increased risk of preterm birth was observed. A study in England, United Kingdom, also showed no signals for preterm birth, extended perinatal mortality or other infant and maternal outcomes.

Steps are under way to carry out a real-world “effectiveness” study of bRSV-preF in low- and middle-income countries (LMICs). The target enrolment is 13 000 pregnant women in four countries (11 sites) in Africa. The primary objectives are: 1) to evaluate the efficacy of RSVA/B-preF against RSV-A or RSV-B subtype confirmed severe lower respiratory tract infection to 180 days of age; and 2) to evaluate the safety of RSVA/B-preF in relation to preterm births in women. The survey will include HIV-positive women whose assessment will be conducted separately.

The global pharmacovigilance database VigiBase (maintained by the Uppsala Monitoring Centre (UMC) on behalf of WHO and its Member States) showed 2007 pregnancy reports for Abrysvo, of which 22.7% (n=455) were marked as serious.

The Pan American Health Organization (PAHO) recommended RSV vaccination in PAHO Member Countries in 2023, and early adopters such as Argentina and Uruguay have achieved coverage levels above 70%. The study is likely to continue in Uruguay where uptake is increasing.

In conclusion, the Committee:

• recommended ongoing close monitoring and planned post-authorization safety surveillance in pregnant mothers living with HIV and other high-risk conditions, as well as for pregnancy outcomes in LMIC settings and at all stages of pregnancy (particularly under 28 weeks gestation);
• emphasized the need to strengthen safety monitoring and pharmacovigilance systems, and recommended WHO to support countries by providing standardized tools and guidance for safety monitoring of maternal vaccines;
• strongly encouraged countries introducing this vaccine to contribute data to the global pharmacovigilance database (VigiBase) and stressed the importance of safety data throughout pregnancy.

WHO study on adverse events of special interest (AESI) – update on background rates

The session aimed to provide a progress update on the AESI background rate study, covering: 1) WHO’s technical and operational support to participating countries; 2) country-level readiness and early implementation experience; and 3) information on related initiatives underway in LMICs.

The studies are under way in Uganda and Zimbabwe to establish background rates for three priority AESIs – Guillain-Barré syndrome (GBS), thrombocytopenia, and neonatal outcomes (preterm birth, stillbirth, neonatal death, low birth weight). Because secondary data sources such as electronic health records are limited in many LMICs, WHO developed standardized protocols for the studies. Reports were received from the three studies which were at various stages of preparation.

The Committee members stressed that diagnosing GBS is not always straightforward so particular care is needed, and that patients may first seek advice from traditional healers and the protocol should take this into account. There may also be patients without national identity papers, so arrangements are needed to deal with such cases. Additionally, since the difference between stillbirth and neonatal death is very sensitive, consistency between facilities must be ensured.

Committee members expressed concern about obtaining sufficient data in digital format in African countries. The importance of coding was stressed. There was a question as to whether one could obtain data with a lower level of consent. The level of BRAVE (Background Rates of Adverse events for Vaccine Evaluation in Africa) consent was considered to be quite high and is usually obtained in the hospital.

The Committee noted that the choice of denominators for estimating background incidence rates should be guided by the availability of local data and the outcome of interest, taking into account factors such as seasonality, migration patterns, treatment exposure, and total deliveries for neonatal outcomes. The choice of denominator should be justified, with limitations clearly reported and discussed. Where necessary, population estimates may be obtained through ad hoc data requests or extrapolated using population growth assumptions.

For case identification and ascertainment, the Committee recommended considering ICD- and MedDRA-coded events alongside GAIA/Brighton Collaboration definitions and involving pharmacists in the ascertainment process. The use of visual scoring systems for gestational age assessment was recommended where appropriate.

For studies assessing multiple outcomes, each outcome should be analysed separately using the most appropriate denominator for the relevant at-risk population. The Committee also highlighted the value of statistical expertise support, the potential use of modelling approaches to support extrapolation to other regions (including leveraging BRAVE feasibility assessments), and the need to align data collection timelines with expected event frequencies.

The Committee supported continued implementation and expansion of studies in LMIC settings, emphasizing the importance of systematically capturing methodological and operational lessons learned, promoting cross-site knowledge-sharing, including with BRAVE, and incorporating what is learned into training materials and capacity-building activities.

Ebola update

As of 22 June 2026, there were 1094 confirmed cases and 277 confirmed deaths in the Democratic Republic of the Congo (DRC), with smaller numbers confirmed in Uganda. Cases were reported from 34 districts in the DRC. Committee members noted that the current outbreak was likely to be disrupting vaccination programmes against other diseases in the affected areas. The outbreak was taking place in some areas that were affected in 2018. A research team was established, and a number of overseas investigators have joined it. A trial site has been identified. A partners’ protocol to assess core therapeutics against the Bundibugyo (BDBV) strain has been set up and is fully approved by the regulatory authorities. Import permits have been obtained for remdesivir and MVP134. The trial is led by national principal investigators and is coordinated by the Ministry of Health. Vaccines targeting the BDBV strain are in early stages of development with Phase 1 likely to start in July and Phase 2 in October.

Mpox vaccine safety updates including ongoing active surveillance study in the Democratic Republic of the Congo

The Committee’s aims were: 1) to review the safety of Mpox vaccines in view of their expanded use; 2) to review global, regional and country experiences in safety monitoring and strengthening pharmacovigilance systems during vaccine introduction; and 3) to identify remaining safety questions. Bavarian Nordic Berna reported on an open-label, multicentre immunogenicity and safety study of MVA-BN vaccine in children 2–<12 years compared with adults 18–49 years for prevention of smallpox, Mpox and related orthopoxvirus infections which concluded that no new safety concerns were identified. Immunogenicity was assessed at two weeks, six months and one year after second dose. Safety/reactogenicity was assessed up to four weeks after vaccination and was comparable to that in adults.

Another study in DRC with MVA-BN vaccine targets pregnant women and infants aged 4–<24 months for assessment of safety and immunogenicity. At the end of May 2026, of the two groups of pregnant women, all 214 in Group 1 had been vaccinated, and follow-up is ongoing. Of the 148 women planned in Group 2, 102 had been vaccinated.

Some countries of WHO’s African Region have rates of serious AEFI exceeding 10% of total reports. The region reported that the main AESI are myocarditis, anaphylaxis, neurological events (e.g. GBS, seizures), severe skin reactions, and deaths temporally associated with vaccination. Key findings of a regional safety review were: 1) injection site reactions were the most consistently reported events, and 2) swellings (injection site and peripheral) were reported more often with MVA-BN.

Examples from a cohort event monitoring study in Kinshasa showed how reactions were classified. Systemic reactogenicity events were dominated by fever and pyrexia, followed by myalgia, chills and fatigue. The presenter was requested to analyse the material and to present the findings to the Committee meeting in November 2026.

A study of the LC16m8 Mpox vaccine in DRC is under way to evaluate the effectiveness and safety of complete vaccination – defined as receiving LC16m8 vaccine at least 14 days before illness onset. Committee members encouraged more information from the data. WHO had developed a research protocol on this through GACVS. The Committee also requested a study focusing on women, especially of childbearing age.

The experts considered the data from Bavarian Nordic were encouraging as they showed no specific safety signal with MVA-BN vaccine in children aged over two years. The Committee recommended WHO and partners to:

• collate passive surveillance data on Mpox vaccines from countries where the vaccines have been used to allow the Committee to make a comprehensive assessment of safety;
• continue coordinating with regional and global partners on the two CEMI studies to ensure timely and thorough analysis of data to provide information on safety of Mpox vaccines, particularly for vulnerable groups (including immunocompromised persons), and to allow regional and global expert committees to set evidence-based policy for the vaccines;
• in the ongoing cohort study, explore: 1) including more pregnant women and young children; and 2) better assessing skin changes following LC16-m8 vaccine to distinguish vaccine “take” from pathological changes – e.g. by applying criteria such as blinded assessment of images of skin lesions; and
• in the trial of MVA-BN among pregnant women by Bavarian Nordic, review data from participants living with HIV infection.

Human papillomavirus vaccine – safety update

Human papillomavirus (HPV) vaccines are widely used in national immunization programmes; 165 countries had introduced the vaccines by the end of 2025. Multiple HPV vaccine products are available globally, with five vaccines (from four manufacturers) prequalified by WHO and three vaccines available under UNICEF procurement for LMICs. Continued expert review is important as programmes expand and newer products are introduced.

Some 80% of the world’s girls have access to HPV vaccination. By the end of 2025, HPV vaccine had been introduced in countries with some 70% of the global burden of cervical cancer. Planned 2026 introductions of the vaccine will raise this proportion to around 90%. The Committee found no new adverse events of concern based on many very large, high-quality studies (GACVS 2017). However, safety concerns can be the basis for low acceptance or disruption of vaccination programmes, so it is important to continue monitoring HPV safety, including of new HPV products.

Committee members received reports on the introduction of HPV vaccines in Bangladesh, India and Nepal. Lessons learned from countries in the South-East Asia Region included: transparent AEFI systems build public confidence in HPV vaccination; most AEFI reports were mild, with very few serious vaccine-related events; inconsistent reporting across countries highlights the need for stronger surveillance and digital tools; and effective monitoring requires strong systems, trained staff, rapid response and proactive communication. It was important to ensure that the HPV campaign – as opposed to independent social media – was proactively controlling the messaging, enabling pre-emptive responses before criticisms became crises.

The Committee welcomed this report and urged countries to ensure that their AEFI data are submitted to Vigibase. Countries were recommended to use clear risk communication strategies and active community engagement during vaccine roll-out, with complementary strategies to build trust in HPV vaccine safety, including through social listening and addressing misinformation.

Acellular pertussis vaccines in pregnancy – safety updates

The Committee discussed GSK’s Boostrix and Sanofi’s Adacel at previous meetings, and the June 2026 joint meeting received a report on BioNet’s VacPertagen and Boostagen which were first licensed in Asia in 2016. VacPertagen contains genetically detoxified PT (PTgen), compared with chemically detoxified PT in other vaccines. Over 1 million pregnant women had been vaccinated in Thailand as of March 2026. The clinical safety database contains 4687 pregnancy outcomes from randomized controlled trials and observational studies and was reported to show no evidence of vaccine-related adverse effects on pregnancy outcomes or on the health of the fetus or newborn.

The most common complication was postpartum haemorrhage reported in 1.87% of women, and the commonest delivery complication was cephalopelvic disproportion. The observed preterm delivery rate of 9.4% was within the historical range. Preterm birth rates following vaccination during pregnancy were comparable to or lower than those in comparator cohorts. Mean birthweight was consistent and within expected ranges. Congenital anomaly rates were below the published background rate of 8.28%. Delivery complications occurred at frequencies consistent with routine obstetric practice and showed no evidence of increased risk following VacPertagen vaccination. No safety signals related to pregnancy outcomes were identified across the three studies.

A study of the effect of maternal pertussis vaccination on neonatal health outcomes in the Dutch Pregnancy Drug Register concluded that maternal pertussis vaccination did not increase the risk of different adverse neonatal health outcomes. There was no difference in neonatal health outcomes by trimester of vaccination.

The safety of Tdap (tetanus, diphtheria and pertussis) vaccination during pregnancy was the focus of a study, published in 2022, which evaluated maternal and infant adverse events after Boostrix during pregnancy. The study, which took place in an integrated, prepaid health-care system, included 16 606 exposed and 16 606 unexposed pregnant women (1.4% multiple gestations). Tdap uptake at Kaiser Permanente in Southern California was 27–38% in 2012–2014, rising sharply after 2014 and exceeding 86% by 2019. It was concluded that, in this large-scale observational study, prenatal Boostrix resulted in no elevated risks for key maternal or infant adverse outcomes.

The Committee was reassured by the data, noting that acellular pertussis vaccines continue to indicate safety in both pregnant women and neonates. Methodological challenges of choosing appropriate comparator populations for post-marketing safety surveillance studies were noted. The Committee stated that it would be helpful to have additional data from LMICs. In discussion, the members were informed that SAGE now has a working group on this vaccine, and it was agreed that the Committee’s recommendations should be deferred until the November 2026 meeting to allow time to assess a recent systematic review and other meta-analyses.

The Committee urged continued pharmacovigilance and active safety surveillance, particularly to monitor rare adverse events, safety following co-administration with other maternal vaccines, and vaccine safety among pregnant women with HIV infection and other underlying chronic conditions.