Chickenpox: India's hidden immunity gap revealed

Many young Indians, including teenagers and young adults, lack immunity to chickenpox, contradicting the view that it is solely a childhood disease. Studies across major Indian cities indicate a substantial portion of these age groups are unprotected. Similarly, a significant number of pregnant women in specific states were found to be unvaccinated and unaware of the vaccine.

Pediatricians are observing an increase in chickenpox cases among older children and adults who have not previously contracted the illness. This trend has prompted public health responses, such as increased surveillance and vaccination encouragement in affected regions like Tamil Nadu and during outbreaks in Kerala.

Innovations in vaccine formulation are crucial for ensuring protection, especially given the fragility of live vaccines and challenges in maintaining the cold chain across India. Newer technologies utilize stabilizers inspired by the resurrection plant, a sugar that allows the plant to survive dry conditions. This approach aims to enhance vaccine resilience and reduce reliance on the cold chain.

Nexipox, a varicella vaccine available in India for nearly a decade, has seen an upgraded version, Nexipox Plus. This enhanced formulation is specifically designed for India's climate, replacing gelatin with a trehalose-based stabilizer for improved potency through storage and handling. Clinical trials show Nexipox Plus has a 98% seroconversion rate after two doses.

To improve vaccination rates, experts suggest scheduling the second dose at the time of the first and increasing transparency regarding vaccine data. The focus is shifting towards ensuring the vaccine administered is as potent as when it left the factory, providing parents with greater assurance.