An infection that causes little more than a rash and mild fever in many people can have devastating consequences when it occurs during pregnancy. Rubella, a contagious viral disease, can cross the maternal–foetal interface and interfere with the development of an unborn child, causing hearing loss, heart defects, cataracts and other complications collectively known as congenital rubella syndrome (CRS).

An estimated 26,859 children were born with congenital rubella syndrome worldwide in 2024, according to a modelling analysis published by the US Centers for Disease Control and Prevention (CDC) in July 2026. Although this represents a substantial decline from an estimated 101,381 cases in 2012, the disease continues to affect newborns in countries where vaccination coverage remains inadequate. But how does the rubella virus enter the cells lining the respiratory tract and the placenta?

A study published in Nature identifies a protein called Nectin-4 as one of the cellular entry points used by the virus. The finding offers a closer look at how rubella establishes infection in two tissues central to its transmission and its effects during pregnancy.

Protein That Opens the Door

Like other viruses, rubella cannot reproduce on its own. It must enter a living cell and use its machinery to produce new viral particles. This often begins when proteins on the virus’s outer envelope bind to specific molecules on the surface of a human cell. These molecules, called receptors, determine which cells a virus can enter. Identifying them helps researchers understand why certain tissues are vulnerable to infection.

The research team found that rubella uses Nectin-4, a cell-adhesion protein, to gain entry into respiratory and placental cells. Nectin-4 normally helps neighbouring cells maintain contact with one another and is present in several human tissues. The virus carries two envelope proteins, E1 and E2, which participate in its interaction with host cells. The researchers found that this viral protein complex interacts directly with Nectin-4. Once the proteins bind, the cell draws the virus inside through a process called receptor-mediated endocytosis, in which a section of the cell membrane folds around an external particle.

To establish the receptor’s role, the team combined protein-interaction analysis with CRISPR-Cas9 screening. They found that cells that were initially resistant to rubella infection became susceptible after Nectin-4 was introduced. Removing or blocking the protein, meanwhile, reduced infection. This offered evidence that Nectin-4 is involved in the virus’s entry into human cells, rather than simply being present alongside the infection.

What Happens at the Maternal–foetal Interface?

The finding has particular relevance to the placenta, the organ through which oxygen and nutrients pass from the mother to the developing foetus. During pregnancy, rubella can infect placental tissue and subsequently reach the foetus. The risk of serious complications is highest during early pregnancy, when the organs are developing. An infection during this period can result in miscarriage, stillbirth or congenital abnormalities.

The researchers examined syncytiotrophoblasts, specialised cells that form the outermost layer of the placenta and come into direct contact with maternal blood. These cells constitute an important part of the barrier between maternal circulation and the developing foetus.

Their experiments showed that Nectin-4 is abundantly expressed in these cells and facilitates rubella infection. When the researchers blocked the receptor, infection in laboratory models of placental tissue declined. The result helps explain how the virus can establish an infection at the maternal–foetal interface. It also identifies a specific cellular interaction that researchers can investigate when studying the transmission of rubella during pregnancy.

There is, however, an important limitation. The team found that rubella could also infect other placental cell populations through pathways that do not depend on Nectin-4. Blocking this single receptor may therefore be insufficient to prevent the virus from infecting the entire placenta.

A Shared Entry Route With Measles

The research also sheds light on rubella infection in the respiratory tract, where the virus initially establishes itself after entering the body. Using laboratory models of human airway tissue, the researchers found that Nectin-4 facilitates viral entry through the basolateral surface of respiratory epithelial cells, which faces the underlying tissue. After entering and replicating within these cells, newly produced viral particles are released from the opposite, airway-facing surface.

This arrangement offers a possible explanation for how rubella infects respiratory tissue and releases viral particles into the airways. Nectin-4 is also recognised as a cellular receptor for the measles virus. The finding that both viruses use the same human protein is an interesting connection, although the two infections involve different molecular interactions and should not be assumed to follow identical pathways.

Could Blocking the Receptor Prevent Infection?

The discovery raises the possibility of developing antiviral treatments that interfere with the interaction between rubella and Nectin-4. A molecule capable of preventing the viral envelope proteins from binding to the receptor could potentially restrict the virus’s entry into susceptible cells. The researchers’ experiments, in which blocking Nectin-4 reduced infection, offer an initial basis for investigating this approach.

For congenital rubella syndrome, the potential application is particularly relevant. Preventing the virus from establishing an infection in placental tissue could eventually help researchers explore ways of reducing the risk of foetal infection.

Such an application remains a research possibility, however. The experiments were conducted using laboratory cell and tissue models; they do not establish that receptor-blocking treatments can prevent congenital rubella syndrome in pregnant women. The alternative routes of placental infection identified by the researchers also present a challenge for any treatment targeting Nectin-4 alone.

Vaccination Remains Central to Prevention

The findings come at a time when rubella vaccination has substantially reduced the global burden of infection, although elimination remains uneven across countries. The CDC recorded 31,593 reported rubella cases worldwide in 2024. This figure reflects infections detected and reported through national surveillance systems, rather than the full number of people infected. The WHO, meanwhile, estimates that around 100,000 infants are born with congenital rubella syndrome annually, using a broader global estimate. These figures come from different reporting and estimation approaches and should not be treated as directly comparable.

By 2024, 179 of 194 countries had introduced rubella-containing vaccines into their routine immunisation programmes, according to the CDC. Global coverage with the first dose rose from 39% in 2012 to 73% in 2024. India includes measles-rubella vaccination in its Universal Immunisation Programme, with two routine doses recommended during childhood. Sustaining coverage is important because rubella infection in an unvaccinated pregnant woman can have consequences that extend well beyond the period of the initial illness.

For now, the identification of Nectin-4 does not change how rubella is prevented or treated. Its importance lies in revealing a previously insufficiently understood interaction between the virus and human cells. Researchers now have a specific receptor to investigate as they work towards understanding how rubella reaches placental tissue and whether that process can eventually be interrupted.

Study involving 10 villages highlights the potential of AI-supported consultations to address rural healthcare gaps, but connectivity and clinical validation remain challenges.

An artificial intelligence (AI)-assisted telemedicine model combining frontline health workers, portable diagnostic devices and remote medical consultations was associated with improved access to healthcare in hard-to-reach villages of Rajasthan, according to a study published in Preventive Medicine Reports in November 2026.

The community-based study, conducted across 10 villages in Balotra district between March 2024 and January 2026, evaluated whether technology-supported consultations could help overcome geographical and infrastructural barriers to healthcare. Researchers compared five intervention villages using assisted telemedicine with five comparison villages where residents followed conventional healthcare-seeking pathways.

During the 10-month intervention period, all 4,401 recorded symptomatic illness episodes in the intervention villages received teleconsultations. In comparison villages, only 1,528 of 3,973 recorded illness episodes (38.5%) resulted in visits to formal healthcare facilities.

The researchers attributed the difference to barriers including long travel distances, transportation difficulties, time constraints and reliance on self-medication or home remedies. However, the study was non-randomised, and the two groups used different methods of recording healthcare utilisation. The findings therefore demonstrate an association with improved access rather than definitive proof that the intervention caused the difference.

How AI supports remote consultations

Under the model, trained frontline health workers, including Accredited Social Health Activists (ASHAs) and Auxiliary Nurse Midwives (ANMs), visited households to identify people requiring medical attention. They recorded symptoms and collected vital signs using portable diagnostic equipment, including digital blood pressure monitors, pulse oximeters, thermometers and electrocardiographs (ECGs).

The information was transmitted through a telemedicine platform to remotely stationed doctors. An AI-supported clinical decision support system analysed the symptoms and diagnostic information to generate probable diagnoses, clinical advice and medication suggestions. Doctors reviewed the recommendations and retained responsibility for clinical decisions.

Of the 4,401 teleconsultation records, 98.6% were managed without referral to higher healthcare facilities. Respiratory conditions accounted for 24.2% of consultations. Portable ECG examinations also identified abnormalities in 21.6% of the 74 patients presenting with cardiovascular symptoms who underwent testing.

The researchers highlighted the role of frontline health workers in facilitating consultations and building trust among rural residents. However, technical disruptions and connectivity problems remained challenges during implementation.

Supporting evidence from recent research

The Rajasthan findings come alongside growing research into the use of AI in primary healthcare. A separate study published in the International Journal of Telemedicine and Applications on October 28, 2026, examined the technical performance of an AI-assisted clinical decision support system developed for rural telemedicine services.

Researchers from the ICMR-National Institute of Health Research, Jodhpur, and IIT Jodhpur evaluated the TeleMed Clinical Decision Support System (CDSS v2.5), which uses machine-learning models to interpret symptoms, identify probable diagnostic categories and support physicians during consultations.

Using five-fold cross-validation on 4,401 patient records, the system achieved an accuracy of 87.2% and a macro area under the receiver operating characteristic curve (AUROC) of 0.962. The system also incorporated a doctor-in-the-loop mechanism through which clinicians could review and modify AI-generated recommendations.

However, the researchers clarified that the results represent internal technical validation rather than independent evidence of clinical effectiveness. External validation and prospective studies are needed before wider deployment. The evaluation also used the same 4,401-record dataset associated with the Rajasthan telemedicine programme, rather than an independent patient population.

A 2026 systematic review and meta-analysis published in Frontiers in Digital Health provides broader evidence. It examined 13 randomised controlled trials involving more than 29,000 participants to assess the integration of AI and telemedicine into primary and family healthcare.

The review found that AI applications improved diagnostic accuracy and clinical decision-making across the included studies. Telemedicine interventions also showed favourable effects on healthcare access, chronic disease management and patient satisfaction, although the pooled clinical effect across 10 trials did not reach statistical significance.

Representative image.Image credit:Pexels

The researchers identified reliable digital infrastructure, healthcare-worker training and integration into existing clinical workflows as important conditions for successful adoption. Connectivity limitations, patient digital literacy, privacy concerns and interoperability between systems were among the barriers.

Scaling digital healthcare requires safeguards

India’s experience with telemedicine also offers a broader context for the findings. A study published in Oxford Open Digital Health in October 2025 examined the adoption of eSanjeevani, the country’s government-led telemedicine service. Analysing programme data from November 2019 to September 2023, researchers recorded more than 163 million consultations across 28 states and eight Union Territories. The provider-assisted model accounted for over 93% of usage, demonstrating the importance of frontline healthcare workers in delivering digital services.

While telemedicine can reduce travel and improve access to doctors, the integration of AI introduces additional concerns relating to diagnostic errors, data privacy and accountability. The World Health Organization has cautioned that AI systems can generate inaccurate or biased recommendations and that healthcare professionals should not rely on automated outputs without appropriate oversight.

The Rajasthan study also acknowledged limitations, including the absence of direct patient health outcomes and systematic assessments of adverse recommendations or diagnostic errors.

As India expands its digital healthcare infrastructure, the findings highlight the potential of combining human medical expertise with AI-supported tools to reach underserved populations. However, improving connectivity, strengthening healthcare-worker training and establishing independent clinical validation will be essential to ensure that technological expansion translates into safer and more equitable healthcare.

Global estimates reveal persistent inactivity among young people, while recent studies highlight the links between physical activity, mental health and learning outcomes.

One in four adolescents worldwide reported no days of physical activity lasting at least 60 minutes during the previous week, highlighting a persistent public health concern among young people, according to a new report released by the World Health Organization (WHO) on November 4.

The report, A Generation Missing Out: Global Trends in Adolescent Physical Activity, 2010–2025, draws on 389 population-based surveys conducted across 140 countries and territories, covering more than 3.2 million adolescents aged 11–17 years. It found that global adolescent physical activity levels have changed little over the past 15 years, with only 14% meeting the recommended 60 minutes of moderate-to-vigorous physical activity every day.

The findings reveal a significant gender disparity. Around 28% of adolescent girls reported no active days during the previous week, compared with 22% of boys. Only 11% of girls achieved the recommended activity level every day, against 17% of boys. Girls were less active than boys in almost every country and WHO region.

WHO Director-General Tedros Adhanom Ghebreyesus said the lack of progress over the past 15 years underscored the need for stronger efforts to encourage physical activity, particularly among girls.

The organisation has also warned that countries are not on track to achieve the global target of reducing physical inactivity by 15% by 2030.

Physical activity linked to mental health and learning

Recent research further highlights the importance of regular movement during adolescence. A study published in JAMA Network Open on October 1, 2026, examined 5,515 adolescents, with an average age of approximately 12 years, to investigate associations between physical activity, brain structure and mental health.

Using daily step counts to measure activity, researchers found that higher physical activity levels were associated with fewer mental health problems and greater cortical thickness in certain brain regions. The study also identified an association between brain structure and mental health outcomes one year later. However, the findings establish associations rather than proving that physical activity directly causes these improvements.

The role of physical activity in education has also been examined in a systematic review and meta-analysis published in the Journal of Global Health in March 2026. Researchers reviewed 90 studies involving approximately 17,000 adolescents to assess the effectiveness of school-based physical activity programmes.

The analysis found that interventions, including physical education sessions, after-school activities and multicomponent school programmes, produced modest short-term improvements in physical activity. However, these gains were not sustained beyond six months, suggesting that isolated interventions may be insufficient to establish lasting behavioural changes.

Together, these studies underline the importance of integrating physical activity into everyday school and community environments rather than treating exercise as an occasional extracurricular activity.

Schools and communities need sustained interventions

WHO identifies several factors contributing to adolescent inactivity, including limited access to safe recreational spaces, inadequate school sports facilities, transport infrastructure and social expectations. Safety concerns and unequal access to sports opportunities can particularly restrict girls’ participation in outdoor activities.

Children enjoy an outdoor activity on a grassy field, stepping over a ladder.Image credit:Pexels

The organisation recommends coordinated action across the health, education, transport, urban planning and sports sectors. Measures include strengthening physical education in schools, improving playgrounds, developing safe walking and cycling routes and ensuring equal opportunities for girls to participate in sports.

Physical activity during adolescence is important for healthy growth, strengthening bones and muscles, cognitive development and mental well-being. Inactivity, meanwhile, is associated with increased risks of non-communicable diseases, including cardiovascular diseases and type 2 diabetes.

The WHO estimates are based on self-reported survey responses. Reporting no active days does not necessarily mean that an adolescent performed no physical activity during the week; it indicates that they did not achieve at least 60 minutes of moderate-to-vigorous activity on any single day.

With the 2030 target approaching, the findings point to the need for sustained public health and education policies that make physical activity an accessible part of everyday life. Schools, in particular, could play a central role in helping adolescents develop healthier habits that continue into adulthood.