Relatively common adverse effects of immunization include high fever and fits. Other symptoms and death have also been linked to vaccinations. Often the symptoms are milder versions of the disease against which the vaccine is administered.
Overdoses of vaccines against the following diseases can cause medical complications: BCG, typhoid, paratyphoid, cholera, plague, tetanus, diphtheria, pertussis, smallpox, rabies, typhus, yellow fever, measles, poliomyelitis, and various viruses.
Research reported in 1994 into adverse reactions to MMR (measles, mumps, rubella) and DPT (diphtheria, whooping cough, tetanus) vaccinations by the Centers for Disease Control and Prevention (Atlanta, USA) has identified 34 major side effects, including asthma, blood disorders, infectious diseases, diabetes and neurological disorders (polio, meningitis, hearing loss and others). There have also been reports of cot deaths linked to the DPT shot and asthma, allergies and arthritis to the rubella injection. Reactions to DPT vaccination were immediate whilst the worst reactions to the MMR vaccine came between eight days and two weeks after the injection. The most significant finding was the increase in the rate of seizures, which rose to three times above the national norm within the first day of a child receiving either a DPT or MMR injection.
The measles-mumps-rubella (MMR) vaccine can cause a rare bleeding disorder called idiopathic thrombocytopenic purpura (ITP). The reaction, caused by the destruction of the platelets that help blood clot, seems to occur most often within the first 2 or 3 weeks of receipt of the vaccine. The resulting thrombocytopenia is described as transient and benign. In the UK, the absolute risk (of hospitalization for ITP) within six weeks of immunization was assessed as 1 in 22,300 doses. It is noted that ITP can also occur in children following a viral infection, such as measles, rubella or mumps. For instance, one case of ITP occurs for about every 3000 rubella infections.
In 2001, The US Food and Drug Administration were investigating more than 100 people whose arthritis or joint pain (symptoms of Lyme Disease) were possibly linked to their vaccination against the Lyme disease.