How are vaccines actually made

In 1900, infectious diseases like pneumonia, flu, and tuberculosis were the leading causes of death in the US, with a life expectancy of just over 47 years. By 2010, chronic diseases like cancer and heart disease became the leading causes of death, with life expectancy extending to nearly 79 years, thanks to improved sanitation and medical advances like vaccines.

Bacteria and viruses are both microorganisms that can cause diseases in humans. Bacteria are hardy organisms that can reproduce on their own and can be treated with antibiotics. Viruses need a host to survive and reproduce, making them difficult to kill once inside the body. Vaccines contain a killed or weakened version of a pathogen and stimulate an immune response to prevent infection. The immune system's innate and adaptive responses work together to fight off pathogens and create memory cells for future protection.

Vaccines have been instrumental in eradicating diseases like smallpox and nearly eliminating polio. They can be live attenuated, inactivated, subunit, conjugate, toxoid, or provide passive immunity. Herd immunity, achieved through widespread vaccination, protects vulnerable populations who cannot be vaccinated. Creating vaccines is costly and complex, but they remain one of the most important medical advances in history.