Common and Serious Side Effects of Vaccines !

Vaccines are for preventing disease but any vaccine can cause side effects. The risks of use of immunization are adjudged to be acceptable in relation to the benefits and safety during the life. Majority of the vaccines have minor side effects like low grade fever, pain at the site of administration and sore arm, but sometimes there can be severe and life threatening anaphylactic reactions. Almost half of the persons experience fever after the administration of vaccines. The fever may be around 100^oF. Pain, redness, swelling and itching around the site of administration are common with injectable-vaccines. Muscle pain and tiredness are also commonly seen. The minor and common side effects usually subside within a few days and respond well to common antipyretics and analgesics. Cooling the injection site and topical application of lignocaine emulsion is generally recommended for decreasing pain. Some less common side effects like headache, nausea, vomiting and mild rash are also seen with most of the vaccines. The rota virus vaccine may cause self limiting diarrhoea.

Rare and serious side effects of vaccines:

Vaccines like MMR, MMRV, Hib and HPV can cause high grade fever (>100^oF) in some cases. The fever has to be controlled quickly and effectively by antipyretics and cold sponging to prevent febrile seizures. In some adolescents, fainting episodes have been reported after administration of HPV, H1N1-inactivated influenza vaccine and MCV_4 (meningococcal vaccine). Arthralgia and Arthritis have been reported in young women after administration of MMR vaccine. Rabies vaccine may also cause arthralgia and arthritis in around 6% cases. Thrombocytopenia (low count of platelets in blood) has also been reported with MMR, varicella vaccine and Yellow fever vaccine. The most serous side effect of Yellow fever vaccine is multi-organ failure or viscerotropic reaction. The varicella vaccine may also cause pneumonia. The BCG vaccine has been reported to cause disseminated tuberculosis and regional adenitis in immnocompromised people. Oral Polio Vaccine (OPV) can cause paralytic polio if administered to already ailing infant/child. The BCG vaccine has also been reported to be associated with the development of Type-1 and Type-2 diabetes mellitus with metabolic syndrome. Life threatening, anaphylactic reactions have been reported with anti-viral vaccines probably due to egg protein of embryonated eggs used to grow various viruses.

Important tips:

• Live vaccines should not be given to pregnant women as there are chances of risk of active disease to the fetus.


• Live vaccines are also contraindicated in patients on immunosuppressive therapy as the risk of developing active disease is there.


• Breast feeding mothers should also not be administered live vaccines and small pox vaccine.


• General health status of infants and children should be assessed before administration of a vaccine.