About the vaccines

Vaccines are probably the most cost-effective tool in the prevention of disease. Most vaccines can be administered in the very early stages of life with protection lasting well into adulthood, with the requirement of probably a further boost in the teenage years. With some vaccines, multiple boosters may be required. In most countries, the widespread use of childhood vaccines has resulted in the dramatic decrease in the incidence of these childhood diseases. With the introduction of the Expanded Program of Immunisation (EPI), there has been an increase in the percentage of children who receive the six childhood vaccines, with some resource-poor countries reporting vaccine coverage of well over 80%. Most new vaccine candidates now target this programme to introduce childhood vaccines although there is a concern that the childhood immune system may be overloaded at such early ages with the added danger of negative interaction of vaccines.

Life Cycle of the Malaria Parasite

Vaccines and immunisation

Without vaccines the world’s population would be at constant risk of contracting numerous potentially lethal diseases and illnesses. Vaccines can be said to provide the most effective defense against infectious diseases. Vaccines have proved, and are still proving to be enormously successful in combating many types of diseases and illnesses. Smallpox has been eradicated, and polio is almost under control, and measles outbreaks and pertussis, have been greatly reduced. However, vaccines are not 100% safe or effective. Certain people can experience adverse events or are not protected from the disease. The safety of vaccines is monitored for each vaccine lot prior to it being released. Science is constantly trying to develop safer, more effective vaccines.

Testing of vaccines prior to licensure

Vaccines undergo rigorous testing prior to being licensed to ensure, as far as possible, that they are safe. Initially computer models are used to predict how vaccines will work. Vaccines are then tested on animals. If tests are successful, vaccines enter into “clinical trials” in humans. Volunteers participating in clinical trials are made fully aware of the risks involved, and are obliged to sign forms of consent. The clinical trial process can take several years, and ethical considerations are very important. Only when regulatory entities, responsible for issuing licenses, are absolute sure that the vaccine in question has been shown to be safe and effective, is a license granted for human use.

Monitoring vaccines for safety is becoming increasingly important. Science is investigating new ways of administering vaccines, by way of mouth as edible vaccines, and needle-free injections. Vaccines are and will remain the paramount tool for the prevention of disease. Vaccines will continue to be held to the highest standards of safety.

With thanks to Centres for Disease Control & Prevention, Vaccines and Immunizations