Diphtheria is caused by bacteria. Affected persons may have fever, sore throat with patches of greyish membrane adhered to the throat and breathing difficulty. In serious cases, it can cause airway obstruction, heart failure, nerve damage or even death. The disease is spread by contact with patient or carrier. Less commonly, a person may get infected through contact with articles soiled with discharges from affected persons.
Tetanus is caused by bacteria, which gets into the body through a break in the skin and produce a toxin that attacks the nervous system. It can cause painful tightening of the body and locking of the jaws, so that the infected person cannot open his/her mouth or swallow. When tetanus affects muscles that help to breathe, the patient can die very quickly.
Pertussis, also known as “whooping cough”, is an acute respiratory illness caused by bacteria. The infected person may initially have non-specific symptoms like runny nose, sneezing, low grade fever and mild cough. The cough gradually becomes more severe and spells of violent coughing can interfere with eating, drinking and breathing. The symptoms can last for weeks. Complications include lung infection, seizures and brain damage. It is spread by direct contact with droplets from patients.
Poliomyelitis is caused by one of the 3 types of Poliovirus (1, 2 and 3). The virus enters the body through oral route and eventually invades the central nervous system. Symptoms include fever, severe muscle pain, stiffness in the neck and back, paralysis, or even breathing difficulty and death.
DTaP-IPV vaccine can effectively prevent the above 4 serious diseases. In Hong Kong, DTaP-IPV is included in the Hong Kong Childhood Immunisation Programme. In order to achieve good and lasting protection, a child should receive 3 doses of DTaP-IPV vaccine in the first year of life (at 2 months, 4 months and 6 months), and another booster dose at 18 months. Two other doses will be given to primary one students and primary six students*. DTaP-IPV can be given with other vaccines. Diphtheria, tetanus, acellular pertussis (reduced dose) & inactivated poliovirus vaccine is recommended for primary six students. Persons with serious allergic reaction to any of the vaccine components or following previous dose of DTaP-IPV vaccine, persons with encephalopathy or other neurological conditions within 7 days following previous dose of DTaP-IPV vaccine or a pertussis-containing vaccine, or persons with serious allergic reaction to certain antibiotics or preservatives should NOT receive DTaP-IPV vaccine. Minor side effects include local reactions (such as pain, redness or swelling). Moderate or severe systemic side effects occur less frequently which include temperature of 40.5°C (105°F) or higher, persistent crying lasting for 3 hours or longer, febrile seizures as well as hypotonic-hyporesponsive episodes. Parents can use anti-fever medication to relieve the symptoms. Infrequently, transient benign swelling of the entire upper arm or/and thigh after the 4th and 5th doses of DTaP vaccines has been reported. If the child develops breathing difficulty or coma (which are extremely rare) after vaccination, please bring him/her to the Accident & Emergency Department of hospitals immediately for management.
* The above information on Diphtheria, Tetanus, acellular Pertussis & Inactivated Poliovirus (DTaP-IPV/4-in-1) vaccine is provided by Centre for Health Protection (CHP) of the Department of Health on their website.