It is easy to assume that premature babies cannot cope with vaccination because their bodies are undeveloped. In fact, even premature babies are born with a functioning immune system. This enables them to survive the transition from the womb (which is largely sterile) to the world, where the baby immediately comes into contact with millions of bacteria and viruses. Much of the immune system is in place by fourteen weeks after conception.
Premature babies can cope perfectly well with vaccines and their immune system will respond to them. However, because premature babies are undeveloped, they are particularly vulnerable to infectious diseases. This makes it even more important that they receive all their routine vaccines at the recommended time. It is not a good idea to delay vaccines or miss them altogether.
It is common for premature babies to have apnoea (temporary stopping of breathing) following vaccination. Very premature babies born before 28 weeks should have their breathing monitored for 48-72 hours after their first set of immunisations.