Disease	Risk of contracting	Risk of death
Diphtheria	2 cases since 1967	Pre vaccine (1930s): approx 1 in 11,000 (0.009%) for all ages. Last death 1967

What is diphtheria?

Diphtheria has all but disappeared in countries such as Ireland that have clean water and sanitation. It is a contagious, bacterial disease of the upper respiratory system. It is mainly spread by the coughing and sneezing of infected persons. The first symptoms appear two to five days after infection. They include a sore throat, headache, coughing, fever and swollen lymph nodes in the neck. As the disease progresses, a thick membrane forms on the surface of the tonsils and throat and may extend into the windpipe and lungs. This membrane may interfere with breathing and swallowing. Diphtheria can lead to breathing problems, airway obstruction, paralysis, heart failure, coma and even death if not treated promptly.

What is the risk of getting diphtheria in Ireland?

Since 1967 there have been just two cases of diphtheria in 2015 and 2016.

What is the risk of death from diphtheria in Ireland?

The last death from diphtheria in Ireland was in 1967. The risk of dying from diphtheria in Ireland in the decade before the vaccine was introduced in the 1930s was approximately 1 in 11,000 (0.009%).

What vaccines are recommended on the pregnancy/childhood schedule for diphtheria in Ireland?

• Infanrix-Hexa (recommended at 2,4,6 and 13 months)
• Tetravac (recommended in Junior Infants)
• Boostrix (recommended for whooping cough but includes diphtheria vaccine)

Do vaccines guarantee protection from diphtheria?

No – you may still get diphtheria even after vaccination.

Are the diphtheria vaccines safe?

All vaccines come with risks, some very serious. Below is a summary of the potential side effects as listed on the patient information leaflets.

Infanrix-Hexa summary of risks. Click here to see full details on this vaccine.

Risks from each dose of 6 in 1 vaccine Infanrix-Hexa (6-in-1)

4 doses recommended at 2,4,6 and 13 months (as per Infanrix Hexa Patient information leaflet Aug 2024)

Observed side effects post administration of Infanrix (post marketing)
Paralysis, numbness or weakness of the arms and legs (neuropathy) Inflammation of some nerves, possibly with pins and needles or loss of feeling or normal movement (Guillain-Barré syndrome) Swelling or infection of the brain (encephalopathy, encephalitis) Infection around the brain (meningitis) Bleeding or bruising more easily than normal (thrombocytopenia)

Risk Category	Observed Side Effects
Up to 1 in 10,000 (0.01%)	Dermatitis
Up to 1 in 1,000 (0.1%)	Bronchitis Rash Swollen glands in the neck, armpit or groin (lymphadenopathy) Bleeding or bruising more easily than normal (thrombocytopenia) In babies born very prematurely (at or before 28 weeks of gestation) longer gaps than normal between breaths may occur for 2-3 days after vaccination Temporarily stopping breathing (apnoea) Swelling of the face, lips, mouth, tongue or throat which may cause difficulty in swallowing or breathing (angioedema) Swelling of the whole injected limb Blisters
Up to 1 in 100 (1%)	Upper respiratory tract infection, tiredness, cough, large swelling at the injected limb
Up to 1 in 10 (1% to 10%)	Sleepiness Loss of appetite High temperature of 38°C or higher Swelling, pain, redness where the injection was given Unusual crying Feeling irritable or restless
More than 1 in 10 (10%)	Diarrhoea Vomiting High temperature of more than 39.5°C Swelling or hard lump where the injection was given Feeling nervous

Other special warnings and precautions
Avoid if child is allergic to formaldehyde, neomycin and polymyxin (antibiotics). Contains para-aminobenzoic acid which can cause allergic reactions. Phenylalanine may be harmful if you have phenylketonuria (PKU), a rare genetic disorder in which phenylalanine builds up because the body cannot remove it properly.

Adverse Events on WHO Vigiaccess Reporting System As of August 2024, 73,005 adverse events have been reported for 6-in-1 vaccines.

Tetravac summary of risks. Click here to see full details on this vaccine.

Risks from each dose of 4 in 1 vaccine Tetravac (4-in-1)
1 dose recommended in junior infants (As per Patient information leaflet Jan 2024)

Observed side effects post administration of Tetravac (post marketing)

Fits (convulsions), with or without fever Fainting Rash, redness and itchiness of the skin (erythema, urticaria) Large reactions at the injection site (larger than 5 cm), including extensive limb swelling from the injection site beyond one or both joints These reactions start within 24-72 hours after vaccination, may be associated with redness, warmth, tenderness or pain at the injection site, and get better within 3-5 days without the need for treatment Swelling of the glands in the neck, armpit or groin (lymphadenopathy) Other reactions seen with vaccines containing the same active substances as this vaccine include: Temporary loss of movement or feeling (Guillain-Barré syndrome) and loss of movement, pain and numbness (brachial neuritis) of the arm and the shoulder Episodes when your child goes into a shock-like state or is pale, floppy and unresponsive for a period of time (hypotonic hyporesponsive episodes)

Risk Category	Observed Side Effects
Up to 1 in 10,000 (0.01%)	High fever over 40°C
Up to 1 in 1,000 (0.1%)	Prolonged inconsolable crying, redness and swelling of 5 cm or more at the site of the injection, fever of 39°C or more
Up to 1 in 10 (1% to 10%)	Diarrhoea, sleep disturbances, hardening of skin at injection site
More than 1 in 10 (10%)	Vomiting Appetite loss Drowsiness Headache Nervousness or irritability Abnormal crying Myalgia (muscle pain) Redness / pain / swelling at injection site Fever of 38°C or more Malaise

Other special warnings and precautions – avoid if:
Allergic (hypersensitive) to glutaraldehyde, neomycin, streptomycin and polymyxin B (antibiotics) Loss of movement and feeling following a previous tetanus vaccine Fever, collapse or shock-like state, persistent inconsolable crying following previous pertussis vaccine

WHO Vigaccess Adverse Events Reporting System As of August 2024, 79,256 adverse events have been reported for 4-in-1 vaccines including Tetravac

Boostrix summary of risks. Click here to see full details on this vaccine.

Risks from each dose of 6 in 1 vaccine Boostrix (3-in-1)
1 dose recommended during pregnancy (As per patient information leaflet Feb 2023)

Observed side effects post administration of Boostrix (post marketing)
Swelling of the face, lips, mouth, tongue or throat which may cause difficulty in swallowing or breathing (angioedema) Collapse or periods of unconsciousness or lack of awareness Seizures or fits (with or without fever) Hives (urticaria) Unusual weakness (asthenia)

Risk Category	Observed Side Effects
Up to 1 in 100 (1%)	Fever greater than 39°C Pain Joint and muscle stiffness Vomiting Diarrhoea Joint stiffness, joint pain, muscle ache Itching Excessive sweating (hyperhidrosis) Skin rash Swollen glands in the neck, armpit or groin (lymphadenopathy) Sore throat and discomfort when swallowing (pharyngitis) Upper respiratory tract infection Cough Fainting (syncope) Flu-like symptoms, such as fever, sore throat, runny nose, cough and chills
Up to 1 in 10 (1% to 10%)	Fever equal to or greater than 37.5°C Dizziness Nausea Hard lump and abscess at the injection site
More than 1 in 10 (10%)	Pain, redness and swelling at the injection site Headache Tiredness Generally feeling unwell