New Delhi, – India has transitioned from the tetanus toxoid (TT) vaccine to the tetanus and adult diphtheria (Td) vaccine as part of its Universal Immunization Program (UIP). The change, launched today by Union Minister for Health and Family Welfare, JP Nadda, at the Central Research Institute (CRI) in Kasauli, Himachal Pradesh, aims to provide broader protection against two potentially life-threatening bacterial infections.
For decades, the TT vaccine has been a cornerstone of injury-associated prophylaxis and maternal care in India, successfully eliminating maternal and neonatal tetanus. However, the TT vaccine offers no protection against diphtheria. Diphtheria, caused by Corynebacterium diphtheriae, is a serious respiratory infection that can lead to breathing difficulties, heart complications, paralysis, and even death.
“Extensive scientific evidence indicates that widespread childhood immunization with DPT group of vaccines has significantly reduced the incidence of diphtheria and tetanus in many countries,” a release from the Ministry of Health and Family Welfare stated. However, immunity to diphtheria can wane over time, necessitating booster doses, particularly in adults.
The World Health Organization (WHO) initially recommended the transition from TT to Td vaccines in 2006, a recommendation reaffirmed in 2017 and through subsequent deliberations of the Strategic Advisory Group of Experts (SAGE) in 2002 and 2016. India’s National Technical Advisory Group on Immunization (NTAGI) subsequently endorsed the switch to Td for all age groups, including pregnant women.
The Td vaccine, formally known as Tetanus and adult Diphtheria Vaccine – Adsorbed, Reduced D-Antigen Content, combines purified diphtheria and tetanus toxoids. These inactivated toxins stimulate the body’s immune system to produce antibodies, providing protection against both diseases. The vaccine contains aluminum phosphate as an adjuvant to enhance the immune response and trace amounts of thimerosal as a preservative.
The CRI, a unit of the Department of Health & Family Welfare, has been instrumental in this transition. The institute successfully completed the development research, obtained necessary testing permits, and secured marketing and manufacturing licenses to begin commercial production of the Td vaccine. The CRI is expected to supply 5.5 million doses to the UIP by April 2026, with production scaling up in subsequent years to meet national demand.
The move to Td is particularly important given the observed decline in diphtheria immunity among adolescents and adults. Public health experts have noted a shift in the age profile of diphtheria cases, highlighting the need for continued protection beyond childhood vaccinations. Diphtheria spreads through respiratory droplets, making vaccination a critical public health intervention.
Tetanus, the other target of the Td vaccine, remains a significant concern, causing painful muscle stiffness and spasms that can be fatal. While tetanus is often associated with contaminated wounds, vaccination is crucial for maintaining immunity.
The launch of the indigenous Td vaccine represents a significant step towards self-reliance in healthcare for India. By domestically producing the vaccine, the country can ensure a consistent and affordable supply, strengthening its immunization program and protecting its population from these preventable diseases. This initiative underscores India’s commitment to national health security and its growing capabilities in vaccine manufacturing.
The transition to Td is expected to extend and strengthen protection against diphtheria, while sustaining the gains made in eliminating maternal and neonatal tetanus and maintaining the effectiveness of routine immunization activities. Health officials emphasize the importance of continued vaccination efforts to ensure widespread immunity and prevent outbreaks of these potentially serious infections.
