Herd immunity is often cited as the ultimate goal of widespread vaccination programs. It’s presented as the magic formula that protects everyone, including the most vulnerable. But what does herd immunity really mean, and is it as straightforward as public health officials make it sound? For parents making critical healthcare decisions, understanding herd immunity is essential.
What Is Herd Immunity?
Herd immunity occurs when a large portion of a community becomes immune to a disease, either through vaccination or natural infection, making it difficult for outbreaks to occur. This concept relies on the idea that immune individuals act as barriers, reducing the likelihood of disease transmission to the few who are not immune.
Shifting From the Disease-Centric to the Vaccine-Centric Narrative
Public health campaigns often frame herd immunity as achievable only through vaccines. While vaccines can contribute to immunity, this approach overlooks the role of natural immunity gained through prior infection. Prior to vaccines, diseases like measles and chickenpox were acquired by all children when the illness was best tolerated with the least difficulty. Everyone had lifelong immunity so they wouldn’t catch the infection when older and more susceptible to complications, and pregnant moms and their babies were also immune during these fragile stages.
Now that we vaccinate, children don’t acquire these illnesses. The downside is that no one has lifelong immunity. The herd become susceptible again when older and can become ill and suffer complications at an age when the infection is worse. Even more concerning, pregnant women and their babies are also at-risk of infection, with even worse complications. Shifting to this vaccine-centric model has had some nuanced consequences that deserve consideration.
Breakthrough Infections and Waning Immunity
One flaw in the vaccine-only herd immunity model is the occurrence of breakthrough infections—cases where vaccinated individuals still contract the disease because vaccines are not 100% effective. Additionally, vaccine-induced immunity wanes over time, requiring booster shots. However, some vaccines, like those for measles, rubella, chickenpox and whooping cough, aren’t well-tolerated by adults, so we can’t sustain herd immunity through these artificial means.
The Role of Natural Immunity
Unlike vaccine-induced immunity, natural immunity is broader and longer-lasting. Individuals who go through chickenpox and measles naturally typically gain stronger and longer-lasting immunity, contributing to community protection without the need for repeated boosters. Natural immunity is also how Covid has now become well tolerated worldwide—everyone eventually acquired the illness multiple times and are now immune from severe disease. Vaccine immunity played a negligible role in this.
Ethical and Practical Concerns
Relying solely on vaccines to achieve herd immunity raises ethical and practical questions. Should individuals with valid medical or personal objections be forced to vaccinate for the “greater good”? In cases where natural immunity is better, should parents be forced to vaccinate instead of allowing their children to go through natural infection?
Oddly, in California, even children who have had natural chickenpox are still mandated to also get vaccinated in order to go to school. And what about the risks associated with adverse reactions to vaccines? Parents should have the right to weigh these concerns when choosing, or not choosing, vaccination.
Conclusion
Herd immunity is a nuanced concept that cannot be reduced to a one-size-fits-all vaccination policy. While vaccines are a valuable tool, they are not the sole solution. Recognizing the contributions of natural immunity and addressing the limitations of vaccine-induced immunity are essential for fostering an honest and effective public health strategy.
Parents, your questions and concerns are valid. Stay informed, seek out reliable information, and make decisions that align with your family’s unique needs. Herd immunity is not just a community goal—it’s a personal journey that requires thoughtful consideration and informed choices.
Stay curious, stay strong, and always advocate for what’s best for your family.
