Td vaccine contains of tetanus toxoid and diphtheria toxoid, but the concentration of diphtheria antigen is lower than that in DPT, DT or Pentavalent etc.
• Td vaccine is sensitive to both freezing and heat.
• It is WHO prequalified
• Open vial policy is applicable to Td vaccine.
• Shake test valid for testing for any damage by accidental freezing
• Td vaccine is safe even for use in the pregnant women
Ministry of Health and Family Welfare has recommended (2019) that any dose of TT in the national immunization schedule (NIS) has to be replaced by Td instead of tetanus alone. This includes the pregnant women too.
However, the existing TT stock should be used up before using Td under UIP schedule. The existing TT vaccines are not to be discarded.
Why the Replacement?
Surveillance data in India has shown that a majority of diphtheria cases in the country, now occur in the age group above 5 years of age.
Widespread coverage with TT has reduced mortality due to tetanus but that due to diphtheria has shown an uptrend. Some other countries have reported diphtheria outbreaks recently. Mortality due to diphtheria reduced after these countries changed over to Td from TT. Hence there is evidence of benefit from the changeover
Studies have shown that
• Immunity to diphtheria continues to decline after the primary doses given in the under 5 age and
• Booster doses are needed for continued protection against diphtheria.
Td is give under the NIS at:
• 10 years of age
• 16 years of age
• Two doses/booster dose for pregnant women
GOI, 2019. STRENGTHENING Td10 and Td16 Vaccine Implementation, Operational Guidelines and Strategic Plan. Immunization Division, MOHFW, New Delhi.