Kermack and McKendrick created a series of mathematical models for the spread of an infectious disease through populations. Kermack and McKendrick's model is still used to study how diseases spread.
They first published a model in 1927. It divided a population into different groups: susceptible, infected, and recovered. The model also took into account the rate of contact between people and the probability that an infection would be transmitted during a contact.
In the 1930s, Kermack and McKendrick developed a more complex model that took into account the incubation period of a disease. This model could also be used to study how the spread of a disease was affected by factors such as vaccination and isolation.
Kermack and McKendrick's work has been used to study the spread of a wide range of infectious diseases, including influenza, measles, and smallpox. It has had a major impact on public health policy and the development of new strategies for preventing and controlling the spread of infectious diseases.