A vaccine contains an inactive organism, or part of an organism, such as a bacterium or virus that is responsible for causing disease. Sometimes, a vaccine contains a weakened live organism. As the organism is inactive or weakened, it will not cause your baby to develop the illness. Instead, the vaccine helps develop your baby’s immune system.

How Vaccines Work

When your baby receives a vaccine, their immune system ‘sees’ the inactive or weakened organism as a threat.  The immune system responds by learning which exact antibodies will kill the organism and develops them.  Once your baby develops the antibodies after a vaccination, they are immunised, or protected, against the live version of the organism.  Later, if your baby encounters the live organism, their immune system will already know what antibodies will fight the infection, and it will quickly make them.  The quick development of antibodies gives your baby’s immune system the upper hand over the disease-causing organism.  

 If your baby has not been vaccinated so is not immunised (protected), the live organism may cause your baby to become ill.  Your baby’s immune system will react to the threat by learning which antibodies will kill the organism and will develop them.  However, this process may be slower than the rate the organism replicates and grows.  This can let the organism get the upper hand over your baby’s immune system and may cause them to become ill.

Mom and Baby

Vaccinations help develop your baby's immune system

Vaccination Policy

In the neonatal unit (NNU) of Cork University Maternity Hospital there is a dedicated nurse available to talk to you about vaccinations.  Depending on the length of your baby’s stay in the NNU, you will have the opportunity to get your baby immunised against a number of serious illnesses during their stay. 

Before your baby has any vaccine, the nurse will discuss the vaccine with you, give you information about it, and ask for your signed consent.  If you have any questions regarding vaccinations, please talk to this immunisation nurse before your baby leaves the NNU.

Sometimes, a baby will not receive their vaccination.  Reasons for this include, they:

  • Previously had a severe local, or general, reaction to the vaccine.
  • Previously had a reaction to another vaccine that contains similar antigenic (antibody stimulating) parts as the vaccine in question. 
  • Have a known, or suspected, hypersensitivity to any of the vaccine’s ingredients.
  • Have an acute illness.
  • Have a fever or high temperature.
  • Have a neurological problem developing.
  • Are receiving steroid therapy.
  • Have thrombocytopenia, or other blood coagulation/clotting disorder.  These babies have an increased risk of bleeding following intramuscular (into the muscle) injections.
  • Are receiving medications/treatments that affects their immune system.

Side Effects

Like any medication, vaccines can have side effects.  Expected side effects include slight redness or swelling at the administration site and a slight increase in temperature.  These minor side effects occur within the first day or two after vaccination, and babies usually recover within the following one to two days. 

Very severe allergic reactions are extremely rare.  Signs of a serious allergic reaction include difficulty breathing, wheezing, hoarseness, weakness, paleness, and a very fast heartbeat.  If treated quickly, the baby will make a full recovery.  All doctors and nurses who give vaccines are able to deal with allergic reactions should they occur.

Some premature babies experience brief pauses in breathing, known as apnoeic episodes, after their first set of vaccinations.  These episodes usually occur within the first 24 hours following vaccination.  The NNU medical team will monitor your baby closely for signs of apnoeic episodes. 

If your premature baby experiences any severe and/or unusual reactions after vaccination, the medical team will review them and treat as appropriate.  The medical team will report the event to the Committee on Safety of Medicines.  For traceability purposes, the batch number of all vaccines is recorded when it is administered and consent forms sent to the Liaison Health Visitor.

Vaccination Schedule

All babies, both preterm and term, follow the same vaccination schedule.  Please see the table below for the vaccination schedule in Ireland.  However, if your baby is unwell with a high temperature at the time the vaccination is planned, it will be postponed.





Oral Drops

2 months

6-in-1, PCV,  MenB


4 months

6-in-1, MenB


6 months

6-in-1, PCV, MenC


12 months



13 months

PCV, Hib/MenC



*6-in-1 = diphtheria, tetanus, pertussis, polio, Haemophilus influenza B (Hib), and hepatitis B vaccine

*PCV = Pneumococcal conjugate vaccine 13 valent

*MenB = Meningococcal B vaccine

*MenC = Meningococcal C conjugate vaccine

*MMR = Measles, mumps and rubella vaccine

*Hib/MenC = Haemophilus influenza B (Hib) and meningococcal C conjugate vaccine

Playing with baby toes

Vaccines are a simple, safe and effective way of protecting babies against certain diseases

6-in-1 Vaccine

The combined 6-in-1 vaccine protects against infections caused by the following six organisms; diphtheria, tetanus, pertussis (whooping cough), polio, Haemophilus influenza B (Hib), and hepatitis B.  It gives very effective immunity (protection) against these disease-causing organisms.  

Pneumococcal Conjugate Vaccine (PCV)

Pneumococcal disease is a bacterial infection caused by Streptococcus pneumonia.   Pneumococcal infections may cause meningitis, pneumonia, ear infections, and respiratory tract infection.  Some people can carry these bacteria in their upper respiratory tract while remaining healthy.  These bacteria spread to others through close personal contact, coughing, and sneezing. 

The PCV vaccine is effective in providing protection against pneumococcal infections in 90 % of children.  The side effects of the PCV vaccine include redness at the site of injection, fussiness and irritability, poor appetite, symptoms of mild tummy upset including vomiting and diarrhoea, and low-grade fever/temperature (38 - 38.5 ° C).

MenC and MenB Vaccines

The meningococcal B (MenB) and Meningococcal C (MenC) vaccines protect against infection caused by meningococcal group B and meningococcal group C bacteria, respectively.  These bacteria can cause meningococcal disease such as meningitis (inflammation of the membranes that surround the brain) and septicaemia (blood poisoning/infection).  

The onset of meningococcal disease can occur quickly, and symptoms include fever, stiff neck, headache, joint pains, and a rash.  Some people can carry these bacteria at the back of the throat or in the nose while remaining healthy.  These bacteria spread to others through coughing, sneezing, or kissing.  

Measles, Mumps and Rubella Vaccine (MMR)

The measles and mumps viruses cause the measles and mumps. Both viruses are from the paramyxovirus family.  The rubella virus, from the Togaviridae family, causes rubella also known as the ‘German Measles’.  The measles, mumps, and rubella viruses spread easily through close personal contact, coughing, and sneezing.  

The measles virus can cause cold-like symptoms, fever, red rash, cough, runny nose, watery eyes, ear infection, diarrhoea, pneumonia, inflammation of the brain (encephalitis), and death.  The mumps virus can cause fever, headaches, muscle aches, tiredness, loss of appetite, swollen salivary glands, deafness, encephalitis, infertility in men, and death.  The rubella virus can cause fever, sore throat, red rash, headache, and red, itchy eyes.  If a woman gets rubella while she is pregnant, she could have a miscarriage or her baby could be born with serious birth defects known as congenital rubella syndrome.

The MMR vaccine is a safe and effective vaccine against these viruses.  This vaccine contains weakened live strains of the viruses.  The MMR vaccine is offered twice, at 12 months and a booster jab at 4-5 years old.  The MMR vaccine can have side effects, such as local soreness at the injection site and surrounding area, fever, a slight rash, and joint stiffness.  On very rare occasions, it can cause a temporary low platelet count.  Any person with a known allergy to the antibiotic neomycin, or other component of the MMR vaccine, should avoid it.


Father holding baby

All babies follow the same vaccination schedule

Haemophilus influenza B (Hib) Vaccine

Haemophilus influenzae type b (Hib) disease is a serious illness caused by Haemophilus influenza group B bacteria.  This bacterium can stay in the back of the nose and throat without causing illness.  However, if the bacterium spreads to the lungs, bloodstream, brain, or bone, it can lead to Hib disease, which may lead to meningitis, pneumonia, a severe swelling of the throat (epiglottitis), septicaemia/blood poisoning, as well as infection of the joints, bones, and the covering of the heart. 

The Hib vaccine protects against Hib disease.  In Ireland, babies are given the Hib vaccine as part of the 6-in-1 vaccine when they are 2, 4, and 6 months old.  A ‘booster’ jab is given at 13 months old, however, at this age the Hib vaccine is combined with the MenC vaccine. 


There are many stains/types of Rotavirus of which Rotavirus A is the most likely to cause illness in humans. Rotavirus A spreads easily through the faecal-oral route through contact with contaminated hands, surfaces, and objects.  Rotavirus infection causes severe inflammation of the stomach and intestines (gastroenteritis), diarrhoea, fever, and vomiting.  Treatment involves management of the symptoms, most importantly, dehydration.  Diarrhoea can cause severe dehydration in babies, which, if left untreated, can lead to death. 

Most children will develop the disease before the age of 3 years if not vaccinated.  In Ireland, the vaccine is given in the form of oral liquid drops.  This oral vaccine is 82 - 94 % effective at protecting against rotavirus infection.  This oral vaccine has some side effects, which include mild diarrhoea, vomiting, blood in their nappy, tummy pain, inflamed skin, and, on rare occasions, a blockage in the gut (intussusception).  If your baby experiences diarrhoea and vomiting, give them plenty of extra fluids (milk and water) to ensure they stay hydrated.

Bacillus Calmette-Guerin Vaccine 

Mycobacterium tuberculosis is a bacterium that causes the disease tuberculosis, or TB.  Mycobacterium tuberculosis can infect any part of the body; it most commonly effects the lungs, causing pulmonary tuberculosis.  This bacterium spreads easily through the air when people with active tuberculosis sneeze, cough, spit, and speak.  Symptoms of tuberculosis include fever, chills, night sweats, loss of appetite, weight loss, fatigue, and meningitis. 

The Bacillus Calmette-Guerin (BCG) vaccine protects against tuberculosis.  It is 70 – 80 % effective against the most severe forms of tuberculosis such as meningitis tuberculosis, but is less effective at preventing pulmonary tuberculosis.  The BCG vaccine is not part of the vaccination schedule in Ireland.  However, there is a low risk of developing tuberculosis due to past vaccination regimens and better living conditions.

Respiratory Syncytial Virus

Respiratory Syncytial Virus (RSV) is a very common respiratory virus.  RSV spreads easily by sneezing, coughing, kissing, close personal contact, and touching surfaces contaminated with RSV such as a worktops or toys. 

Symptoms of RSV infections include a runny nose, decreased appetite, coughing, sneezing, fever, wheezing.  However, in very young babies signs of RSV infection may only show as decreased activity, irritability, and breathing difficulties.  RSV infection can lead to bronchiolitis and pneumonia; both involve inflammation in the lungs. 

In Ireland, ‘the RSV season’ starts in October and continues until Spring.  Babies ‘at risk’ or the most vulnerable to RSV infection include:

  • Babies born less than 32 weeks’ gestation
  • Babies less than 6 months old at the start of RSV season.
  • Babies with chronic lung disease.
  • Babies with severe congenital heart disease.

Babies identified as ‘at risk’ of RSV infection are offered the RSV injection during their first RSV season.  This injection contains antibodies to fight against RSV.  This injection is not a vaccine because it contains antibodies instead of inactivated, or weakened, organisms that stimulate the immune system to produce its own antibodies. 

This RSV injection, called ‘Synergis® Palivizumab, is given monthly from mid-October until mid-February.  If your baby is discharged from hospital during the RSV season, they will receive their first dose before leaving the hospital.  Once discharged you must collect the prescription for ‘Synergis® Palivizumab’ from your pharmacy.