Three Historical Images That Say a Lot About How Vaccines Work

Even breakthrough infections tell us that vaccines are working. Here are three photographs that tell us how and why.

The Omicron variant surge being observed in different parts of the world at the end of 2021 and beginning of 2022 is confusing the public because so many of those who are being diagnosed as infected were partially or fully vaccinated. Vaccines are not a magical forcefield that prevents a virus from landing on a person and beginning an infection. What vaccines do is give the body’s immune system advanced warning of what a virus (or bacteria) looks like. Armed with that information, the immune system is ready to clear out the virus as soon as possible, often preventing infection. And, if the infection is underway, the infection can be halted ahead of any significant symptoms.

This is why those who are vaccinated are exhibiting less serious symptoms than those who are not when it comes to the novel coronavirus infection, COVID-19. Of course, no vaccine is 100% effective, so there will be those who do not mount a significant immune response and can still be severely affected by an infection. At a population level, well-vaccinated people are less likely to be infected, or to show symptoms if they are infected. This is why the novel coronavirus is forecast to become endemic, a nuisance virus like all the other viruses that cause cold and flu-like symptoms. From a public health perspective, it would be better for everyone to achieve that immunity artificially through vaccination because the risk of a vaccine adverse event is significantly lower than the risk of complications from a natural infection.

This concept of infection-with-immunity is not new. Ever since Edward Jenner developed the smallpox vaccine back in the late 1700s, observant clinicians and scientists have noticed a stark difference in the presentation of vaccine-preventable diseases between the vaccinated and the unvaccinated. They noticed that unvaccinated and non-immune (from previous infection) people have a much higher risk of severe disease. On the other hand, vaccinated and/or immune people can still show some signs of the disease, but they are not as severe as the full-blown disease would be on average. Even with…