The 1960s marked the introduction of Albert Sabin’s oral polio vaccine, a pivotal moment in history. When asked about the dosage required, Sabin simply responded, “Just two drops”. It captured the public’s imagination. The invention led to widespread vaccination campaigns, with parents eagerly lining up to protect their children from the crippling effects of polio. Such was the collective trust in science and the palpable fear of the disease that vaccination became a societal imperative. Fast forward to today, and we face an agonising paradox. The World Health Organization estimated that 1 lakh people died from measles in 2023 alone, despite the availability of a safe vaccine. The United States, the very nation that pioneered measles vaccines, grapples with measles outbreaks. The resurgence is not due to a lack of access or resources but stems from a phenomenon best described as wilful ignorance, fuelled by misinformation resulting in vaccine hesitancy.
Measles evolved from a zoonotic source from rinderpest (like COVID-19, which came from bats). Persian physician Muhammed Razi wrote the earliest recorded description of measles in the 9th century. From Europe, measles spread globally through exploration and colonisation, devastating indigenous populations who lacked prior immunity. The 1529 measles outbreak in Cuba killed two-thirds of the native inhabitants. Catastrophic epidemics occurred among Native American tribes following European contact. Even isolated communities, such as India’s Nicobarese tribes, experienced severe mortality when exposed. In the 19th century, measles epidemics nearly decimated the Great Andamanese tribes. Historically, isolated populations remain highly vulnerable, as shown by the Faroe Islands epidemic of 1846, where measles affected almost every inhabitant due to a lack of immunity.
Understanding Measles
Measles is a highly contagious RNA viral disease caused by the Morbillivirus hominis from the Paramyxoviridae family. Transmission occurs through respiratory droplets when an infected person coughs or sneezes. The virus can remain viable on surfaces for up to two hours, making it highly transmissible with a basic reproduction number (R₀) ranging from 12 to 18. The groups most vulnerable to measles are unvaccinated young children under five years, individuals with compromised immune systems, pregnant women, and those who are malnourished.
After an incubation period of 10–14 days, initial symptoms include high fever, cough, runny nose (coryza), and conjunctivitis. Koplik’s spots, small white lesions inside the mouth, are a hallmark sign preceding the characteristic maculopapular rash that spreads from the face downward. Upon entering the body, the measles virus infects epithelial cells of the respiratory tract before disseminating to the lymphatic system and other organs. This widespread infection suppresses the immune system, rendering individuals susceptible to secondary bacterial infections. Vitamin A supplementation during measles infection has been shown to reduce morbidity and mortality.
Diagnosis is usually through clinical examination. Complications are severe, including pneumonia, encephalitis, and subacute sclerosing panencephalitis (SSPE), a fatal progressive neurological disorder and death (in 0.3 to 30 per 100 cases). Measles has no treatment. The management involves hydration, fever control, and mandatory case reporting for surveillance and outbreak control.
Historical roots of vaccine hesitancy
Vaccine hesitancy is not a new phenomenon. Fear and hesitancy have accompanied vaccination efforts since Edward Jenner’s time in the 1800s (father of vaccines). Early vaccination methods were rudimentary and often met with public apprehension. For instance, Jenner’s pioneering smallpox vaccine involved scraping material from cowpox sores and introducing it into open cuts on the recipient’s arm. This crude method frequently resulted in pain, fever, and localised infections, with recovery periods extending from one to three months. Such experiences contributed to early resistance against vaccination. Vaccines also lack the emotional tangibility of interventions such as surgeries, CPR, or emergency procedures. People find it difficult to relate to preventive injections against diseases they might never witness (if vaccinated). Ironically, past vaccination successes led to declining disease visibility, reducing fear and urgency, inadvertently fuelling complacency and hesitation about vaccines today.
Modern vaccine hesitancy and the role of social media
The modern anti-vaccine movement gained significant momentum following a 1998 study by Andrew Wakefield, which falsely linked the measles, mumps, and rubella (MMR) vaccine to autism. Although the study was retracted and discredited, it sowed seeds of doubt that persist to date. Compounding this issue, corporate rivalries and misinformation campaigns have further eroded public trust. The advent of social media platforms has amplified conspiracy theories, allowing misinformation to spread rapidly and widely. Notably, AI-powered algorithms designed to maximise user engagement and watch hours inadvertently promote sensationalist content, including anti-vaccine narratives, leading to increased vaccine hesitancy.
Measles vaccination
The measles vaccine was first developed in 1963 by John Enders and Thomas C. Peebles after isolating the virus in 1954. It was later improved in 1968 by Maurice Hilleman, who introduced the safer Edmonston-Enders strain, now widely used in vaccines. Other strains include Schwarz (RA27, AIK-C, CAM-70), derived from the earlier Edmonston B strain. These live attenuated vaccines are available as monovalent measles vaccines or combination vaccines like MR (Measles-Rubella) and MMR (Measles-Mumps-Rubella), providing long-term immunity.
In India, measles is a notifiable disease, and the government provides the Measles-Rubella (MR) vaccine as part of the Universal Immunisation Programme. The private sector offers the Measles, Mumps, and Rubella (MMR) vaccine, providing broader protection. Both vaccines are safe and provide 97% effectiveness for two doses (for every 100 vaccinated people, 97 are protected). Both measles and smallpox are viral diseases exclusive to humans, lacking animal reservoirs, which theoretically positions them as candidates for eradication. Previous infection confers long-lasting immunity, and effective vaccines are available for both. The global success in eradicating smallpox underscores the potential for measles eradication.
Current measles resurgence
The recent measles outbreak in the United States, a nation with advanced healthcare infrastructure, underscores the consequences of vaccine hesitancy. This resurgence is not due to a lack of access or socioeconomic disparities but arises from wilful ignorance and misinformation. It highlights a critical need for robust public health education and reinforcing vaccine trust. The seriousness of the measles resurgence is evident, as even prominent anti-vaccine figures like Robert F. Kennedy Jr. reversed their stance. Similarly, countries like the United Kingdom have experienced measles outbreaks linked to declining vaccination rates in the mid-2000s. It is ironic that the USA, once a pioneer in vaccine development, now succumbs to a manufactured disaster, where wilful ignorance revives a disease that science had long conquered, proving knowledge alone is not enough.
Published – March 24, 2025 05:29 pm IST