Vaccination is a medical procedure that helps to protect people from contracting diseases. It involves injecting a person with a “dead” or “modified live” form of the virus, bacteria, or other microorganism that causes the disease. As the person’s immune system fights off the weakened form of the pathogen, they develop immunity to that disease. Vaccines are typically given through an injection into the muscle (intramuscular) or under the skin (subcutaneous).
The history of vaccination dates back to 1796 when English physician Edward Jenner observed that milkmaids who had contracted cowpox were immune to smallpox. He went on to develop a vaccine using material from cowpox lesions and showed that it could be used to protect people from smallpox. This was a major breakthrough in medicine as smallpox was a highly contagious and often deadly disease. The success of Jenner’s work led to further research on vaccines and eventually led to the development of vaccines for many other diseases such as polio, measles, mumps, rubella, diphtheria, pertussis (whooping cough), and tetanus.
Today, vaccination is considered one of the most effective public health interventions available. It is estimated that vaccinations will prevent 2-3 million deaths each year worldwide. Immunization programs have led to the eradication of smallpox and elimination of poliomyelitis (polio) in many parts of the world. Measles mortality has also been reduced by more than 99% since 2000 due largely due to increased vaccination coverage.
Despite these successes, there are still many challenges when it comes to vaccinating populations around the world. One challenge is ensuring that enough people are vaccinated in order to achieve “herd immunity” which protects even those individuals who cannot be vaccinated for medical reasons such as cancer patients or those receiving radiation therapy. Another challenge is overcoming cultural barriers and misinformation about vaccines which can lead some people to refuse vaccination for themselves or their children despite its well-documented effectiveness at saving lives.