Types of Vaccines

• Dead Inactivated: Killed by heat or chemical treatment (e.g. Polio), it can be given to immunocompromised patients, but several doses needed and expensive
• Live, Weakened (attenuated): Mimics a true infection (e.g. BCG) , needs only one dose given, is inexpensive but cannot be given to immunocompromised patients or during pregnancy and takes considerable time and testing
• Subunits or bits of pathogen (e.g. hepatitis and meningitis) and purified toxins/toxoids; inactivated bacterial toxins (e.g. diphtheria, tetanus)
• Viral Vector: Contains unrelated/harmless virus, modified to deliver disease’s (e.g. Ebola) genetic material, our cells use it and make its protein, which triggers an immune response, it needs to be stored at cold temperatures
• Genetic (nucleic acid vaccine): Contains a segment of the diseases’ (e.g. Covid-19) genetic material (DNA or RNA), triggers a response; it is low cost, fast development, but may need low temperature storage
• Protein: From pathogen (e.g. Hepatitis B), it has a good safety record and is usually injected with adjuvant to boost the immune response