| Disease |
Effects of Disease |
Side Effects of Vaccine |
| Incidence Before Vaccination |
Incidence After Vaccination |
Polio
Spread by faeces and saliva. Incubation: 1-2 weeks.
Infection may lead to fever, headache, nausea and vomiting, muscle weakness and paralysis. |
1% of infections have clinical symptoms, but about 1 in 20 hospitalized patients dies and 50% of survivors remain paralysed. |
IPV used in Canada so vaccine associated polio, though very rare, is no longer a risk.
Local discomfort or inflammation in 5% of recipients.
– see side effects of DtaP vaccine below for combination use. |
Range 2.5-28.3 /100,000
Epidemic years had up to 20,000 cases of paralytic disease. |
Indigenous disease eradicated
from the Americas. Still endemic
in other parts of the world. |
Diphtheria
Spread by nasal droplets. Incubation: 2-5 days.
Infection leads to severe pharyngitis and cervical adenopathy.
Patient is infectious for up to 2 weeks. |
Case fatality rate 5-10%.
Toxin may lead to myocardial and neurological complications. |
DTaP vaccine – about 20% have local discomfort or inflammation, 5% have fever. A transient nodule may develop at the injection site, lasting a few weeks. Up to 70% at the 4-6yr booster develop redness and swelling. |
| Highest in 1924 with 9,000 cases that year. |
Now 2-5 reported cases per year, none reported in 1996. |
Tetanus
Bacteria present in soil and animal faeces. Incubation: 3-21 days.
Causes painful muscular contractions and convulsions. |
Case fatality about 10%. Risk is greatest for the very young or old. |
See above – side effects of DTaP vaccine. Local erythema and swelling not uncommon with adult boosters, and increasing with age. Peripheral neuropathies have been rarely reported. |
| Average 40-50 deaths per year. |
3-5 cases per year reported, only 5 deaths in the last 18 years and none since 1991. |
Pertussis
Spread by cough and nasal droplets. Incubation: 7-10 days.
Symptoms include runny nose and irritating cough, which may develop into whooping cough. |
About 1% case fatality in patients under 6 months, from pneumonia or fatal encephalopathy (usually hypoxic). Several deaths still occur every year, particularly in unimmunized infants. |
See above – side effects of DTaP vaccine.
Rate of reactions to acellular pertussis vaccine is less than with whole cell. |
| Average 153 /100,000 |
Average 10 /100,000 |
Hib
Spread by nasal droplets. Incubation: 2-4 days. Presents as an acute illness with fever, vomiting, and lethargy (symptoms of meningitis) in 55-65%. In the remainder, it can also cause epiglottitis, pneumonia, bacteremia and other complications |
Case fatality of meningitis is 5% (10-15% of survivors have permanent neurologic sequelae and 15-20% have deafness). |
5% have discomfort or local inflammation, 2% have fever. Usually given in combination with DT (see above – side effects of DTaP vaccine). |
| Leading cause of bacterial meningitis in infancy. About 2,000 cases per year |
Only anecdotal cases now being reported, less than 60 cases per year in the last few years. |
Measles
Spread by cough and nasal droplets. Incubation: 1-2 weeks.
Symptoms include fever, sore throat, cough, runny nose, itchy eyes and a red rash that starts on the face and spreads to the rest of the body. |
Complications such as bronchopneumonia and otitis media in about 10%.
1/1,000 encephalitis (case fatality 10%, permanent sequelae 25%).
1/25,000 develops SSPE. |
5-10% have discomfort, local inflammation or fever with or without a non-infectious rash.
1/1 million recipients develop encephalitis.
About 1/24,000 develop transient thrombocytopenia. |
Cyclic with increasing incidence every 2-3 years.
About 300,000 to 400,000 cases per year estimated. |
Recent outbreaks with 11,000 cases (1989) and 2,300 (1995). With 2 dose schedule, now fewer than 400 cases per year. |
Mumps
Spread by saliva. Incubation: 2-3 weeks. Symptoms include fever
and parotitis. |
1/ 200 children develops encephalitis. 20-30% of post-pubertal males develop orchitis, 5% of females develop oophoritis.
Occasionally, mumps causes infertility or deafness. |
Fever and a mild skin rash occasionally occurs.
1% of recipients may develop parotitis.
1 in 3 million recipients may develop aseptic meningitis. |
Highest in 1942 with 52,344 cases
Average incidence 136 /100,000 |
Average incidence 2.35 /100,000, or about 500 cases annually. |
Rubella
Spread by nasal droplets. Incubation: 2-3 weeks. Symptoms include fever, headache, itchy eyes, cervical adenopathy and rash. |
50% develop a rash and adenopathy; 50% of adolescents and adults have acute arthralgias or arthritis; 1/6,000 develops an encephalopathy. Infections in the first 10 weeks of pregnancy have a 85% risk of CRS. |
About 10% have discomfort, local inflammation or fever. About 5% have swollen glands, stiff neck or joint pains. About 1% develop a noninfectious rash. Transient arthralgias or arthritis may occur, more in post-pubertal females. |
Highest in 1936 with 69,401 cases
Average 149 /100,000 |
Average of 8.5 /100,000.
About 2,000 cases reported annually. |
