A biological product given to healthy people to prevent life-threatening infectious diseases. Vaccines prevent infection while treatment (drugs) aims to cure people who are ill.

According to the WHO vaccines are the single most, life-saving and cost-effective medical intervention so far. They have eradicated smallpox, dramatically cut child mortality rates, and prevented lifelong disabilities. Their success has revolutionised global health and they have saved millions of lives.

How do Vaccines work?

Vaccines elicit an immune response against specific viruses or bacteria. The immune response stimulates what is known as lymphocytes in the body, to produce antibodies and other inflammatory responses to kill off, inactivate or neutralise the germ when a person is exposed or infected. The antibody response is generally specific to individual germs (pathogens) which is why different types of vaccines are needed to fight different types of viruses or bacteria.

Currently available vaccines protect against more than 25 debilitating or life-threatening diseases, including measles, polio, tetanus, diphtheria, meningitis, influenza, tetanus, typhoid, and cervical cancer. Each year, it is estimated that immunisation of children prevents at least 2.5 million deaths. However, there still remain approximately 1.5 million deaths that could be prevented each year if vaccines were more accessible and widely used.

There is no vaccine available that prevents COVID-19. However, the mRNA candidate vaccines for COVID-19 have shown great promise with manufacturers reporting between 90% and 95% efficacy after Phase III clinical trials. Pfizer will apply for Emergency Use Authorisation for its vaccine.

As of mid-November 2020, there were over 50 COVID-19 vaccine candidates in human clinical trials and over 80 in animal studies.

TIP: The progress of these global trials can be tracked on the WHO site or see the New York Times vaccine tracker at…


Infectious Disease Prevention Vaccines


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