Measles, mumps, and polio are infectious diseases that once caused public health crises in the U.S. With the development of vaccines, herd immunity, or “community immunity,” as it is commonly referred to, helped to nearly eradicate these diseases. Today, as the COVID-19 pandemic continues, questions about what herd immunity is and how it can be achieved are at the forefront of many peoples’ minds.
The World Health Organization (WHO) defines herd immunity as “the indirect protection from an infectious disease that happens when a population is immune either through vaccination or immunity developed through previous infection.” One of the biggest benefits of achieving herd immunity is protecting those who are immunocompromised or who cannot receive a vaccine for a preventable disease. Children, as well as adults of any age who have been diagnosed with conditions such as dementia or other neurological conditions, Down Syndrome, and substance abuse disorders, are considered to be immunocompromised and at an increased risk of becoming seriously ill from COVID-19.
COVID-19 Pandemic – The Importance of Community Immunizations
Herd immunity is the best defense to protect our loved ones, especially those who may be more vulnerable to aggressive illnesses and viruses such as COVID-19. There are two ways herd immunity from COVID-19, or SARS-CoV-2, can be achieved: through natural infection or protective vaccines.
Herd immunity achieved through natural infection requires an estimated 70 percent of the U.S. population to contract COVID-19 and recover from the virus. Individuals infected would develop natural antibodies against COVID-19, protecting them from contracting the virus again and spreading it to others. However, community immunity achieved by way of natural infection can have serious consequences. For example, those who contract the virus naturally are at risk of death or long-term health implications, which could be devastating for the population as a whole. There is also the question of reinfection, or how long the natural antibodies will protect the individual from contracting the disease again or spreading it to others.
The second way to achieve herd immunity is through vaccination. Vaccines provide individuals with protective antibodies without causing illness or resulting complications. Herd immunity has been successfully achieved through vaccinations for contagious diseases such as smallpox, polio, diphtheria, and rubella. However, vaccines for COVID-19 are still relatively new, and it is not clear how long individual vaccinations can provide protection against the virus.
For vaccines to be effective, all populations and geographical demographics worldwide must reach herd immunity to prevent the virus from spreading through international travelers. Otherwise, as infection rates continue to rise, so does the increased risk of the virus mutating. This can create new variants that may not be protected by the existing vaccines. In addition, skepticism about the benefits or perceived risks of vaccines can hinder the development of herd immunity.
Advocating for Our Loved Ones – Protecting the Immunocompromised Through Herd Immunity
Vaccine rollouts across the U.S. have made multiple vaccines available to all eligible adults and children over the age of 12. At the time of writing, 57 percent of the total U.S. population have received at least one dose of the COVID-19 vaccine, and 49 percent are fully vaccinated according to the CDC. However, until the vaccination rate reaches 70 percent, herd immunity cannot be achieved. It is imperative that those who are eligible receive their vaccination to protect those who cannot.