Indications
Diphtheria toxoid is a vaccine component that protects against diphtheria, a serious bacterial infection of the throat and nose that can block breathing and damage the heart and nerves. It is not given alone but as part of combination vaccines, such as:
- Pentavalent and hexavalent vaccines for infants (with tetanus, whooping cough, hepatitis B, Haemophilus influenzae type b and sometimes polio)
- Td vaccine (tetanus and diphtheria) for older children, adults and pregnant women
How It Works
The toxoid is the diphtheria toxin that has been made harmless. It cannot cause disease, but it teaches the immune system to produce antibodies against the real toxin. If the person is later exposed to diphtheria, these antibodies neutralise the toxin before it can cause serious illness.
Dosage and Administration
It is given by a trained health worker as an injection into a muscle, usually the outer thigh in infants or the upper arm in older children and adults. The number of doses and timing follow the national immunisation schedule (in Bangladesh, the EPI schedule) or the doctor’s advice; infants usually receive a primary series in the first months of life, with boosters later. Td is given to women of childbearing age and during pregnancy according to the national schedule.
Interactions
It can usually be given on the same day as other routine vaccines, at different injection sites. People taking medicines that suppress the immune system (such as high-dose steroids or cancer treatment) may have a weaker response. People on blood thinners should tell the health worker, as bruising at the injection site is more likely.
Contraindications
Do not give to anyone who had a severe allergic reaction (anaphylaxis) to a previous dose or to any component of the vaccine. Vaccination is usually postponed during a moderate or severe illness with fever; a mild cold is not a reason to delay.
Side Effects
Common side effects include:
- Pain, redness and swelling at the injection site
- Mild fever
- Irritability, crying, drowsiness or reduced feeding in infants
- Tiredness, headache or body aches in older children and adults
These usually settle within 1 to 3 days. A small lump at the injection site may last a few weeks.
Seek urgent medical help if there is difficulty breathing, swelling of the face or throat, widespread hives, high fever above 40°C, a seizure, unusual floppiness or unresponsiveness in a baby, or crying that does not stop for 3 hours or more.
Pregnancy and Lactation
Td vaccine containing diphtheria toxoid is safe and routinely recommended during pregnancy in many countries, including Bangladesh, and it also helps protect the newborn against tetanus. It can be given while breastfeeding.
Precautions and Warnings
Tell the health worker about any previous reaction to a vaccine, bleeding disorders, or a weakened immune system. Wait at the vaccination centre for about 30 minutes after the injection so any allergic reaction can be treated. Too-frequent booster doses can increase local reactions, so follow the recommended schedule. Keep a record of each dose on the vaccination card.
Overdose
Overdose is unlikely because a health worker gives a single measured dose. An extra dose given by mistake may cause stronger soreness and swelling; report it to the health worker.
Therapeutic Class
Vaccine; bacterial toxoid (component of combination vaccines).
Storage
Store in a refrigerator at 2 to 8°C. Do not freeze; vaccine that has been frozen must be discarded. Protect from light. Handled and stored by health facilities as directed on the pack.
Prepared by the Oshud Alo team from standard drug references. For information only; always follow your doctor's advice.