When is getting an infection actually a good or a bad thing? Let’s start by talking about herd immunity. What exactly is it, and why have we been hearing about it so much during the Covid-19 pandemic?
Herd immunity, as described by the CDC, is a situation in which a sufficient proportion of a population is immune to an infectious disease (through vaccination and/or prior illness) to make its spread from person to person unlikely. When a group has a high enough percentage of immunity in its population, transmission becomes increasingly difficult for a disease to spread to even the more immunocompromised members of the community.
Although, herd immunity is obtained at different levels of community immunity depending on the disease. Some highly infectious diseases, such as measles, require about 94% herd immunity to stop community spread. According to the Mayo Clinic, about 70% of the US population would need to have immunity from Covid to stop our current pandemic.
So how do we even get herd immunity? Well, we can achieve herd immunity through two different methods. The first method is infection. Herd immunity can be achieved by having a large amount of the population getting the virus naturally. The downside of this method is that the population has to get sick and recover. Depending on the disease, short or long-term side effects or mortality rate can be very detrimental to the population.
Germs have most likely existed for around 3.5 billion years (the age of the oldest living organisms, bacteria). Modern humans have only been around for about 130,000 years. Humans have only been around for a fraction of the time diseases have, but they are both a part of nature. However, in response to their presence, humans have developed immune systems that have been a part of a back and forth protecting us from harmful germs. Terrestrial vertebrates such as humans have complex immune systems that have evolved to protect them from new immunological dangers. Getting sick is a part of life. Diseases have always been a part of nature, and that is especially true of the current time period, the Anthropocene. The Anthropocene is the current geologic age where humans have a substantial effect on their environment. During this time period, the way we interact with nature through contributing to climate change, deforestation, and urbanized lifestyles has increased the likelihood of pandemic-like illnesses to sweep over our communities. Deforestation causes loss of habitat; and with loss of habitat animals will be forced to come into contact with animals they originally wouldn’t have, including humans. This increases the chance for germs to spread to new hosts. Climate change and urbanization are also causing organisms to live closer together, allowing for diseases to spread more easily through communities. So, while diseases are a part of life and nature, occasionally there is one germ that can come around and have a profound effect on society.
I remember the news stories when NYC was first getting taken over by Covid. Medical personnel lacking PPE, hospitals overflowing, using ice trucks to store the deceased, and exhausted nurses and doctors. All of that resulted in just 22% herd immunity. At 22% herd immunity most of the population of NYC is still susceptible to Covid. If natural infection was the only way forward, so many more of NYC’s citizens would die or become severely ill. However, because this happened NYC was quick to understand the importance of instituting mitigating measures to slow the spread of the disease. Andrew Cuomo, the governor of New York, is similar to Rand Paul in that he is in a position that he can implement policies. When Andrew Cuomo, governor of New York, saw what was happening in his state, he used his ability to implement policies to follow scientific guidance surrounding closures, social distancing, masks, etc. As a result, the rates in NYC decreased. Not because of herd immunity, but because of serious measures against Covid. If we look at a different state, such as Florida, that did not take measures against Covid seriously, there were consecutive days in the state where they were having 10,000 to 15,000 new cases a day. This lacking approach to Covid caused thousands of preventable deaths. Even after months of lockdown the US is not close to herd immunity. All of the preventable deaths and long-term health complications that I’m seeing in people are going to continue with the natural spread. This is why the global race for a vaccine is so important.
The second method of reaching herd immunity is through vaccinations. By developing a vaccine for an infectious disease, we are able to reach herd immunity without having to subject our population, community, and families to the side effects and overall awful experience of falling ill. By using widespread vaccinations, we can also protect our most vulnerable members of society, like our loved ones in an older or younger age range, immunocompromised individuals, or those with allergic reactions making them unable to receive vaccines. Herd immunity is a good thing. When we have a disease like Covid, however, natural infection will cause crippling long-term effects in what were healthy people, and hundreds of thousands of preventable deaths. This is why herd immunity is good, but it depends on the method used to obtain it.
Immunity is an important part of preventing diseases in my home. Herd immunity helps me protect my family, friends, and people I come across every day. When paired with vaccines, I am able to protect more people in my community. I have a small child in my home, and older family members who I come into regular contact with. My family (my herd) and I get our vaccines and flu shots every year to help protect those more immunologically vulnerable members of our family. By doing this, my herd is creating a mutually benefiting environment where our personal actions protect those around us. The actions that we take to protect our family also protect the members of our communities and your herd too.
Humans are a part of nature, and so are diseases. Individual actions have a larger inter-connected effect on surrounding environments and society. The same thing could be said about the Covid virus spreading through the country. Society as a whole needs to develop a larger scope of thinking about how the actions of individuals affect the environment and planet. The factors I mentioned earlier, climate change, deforestation, and urbanization, are keeping steady and increasing. If these continue as they are currently, we can expect more pandemic-like diseases in our future. And when it happens, society will have to come together again to figure out the best way of adopting herd immunity to combat the disease.
As for my advice for the rest of this year, think critically, look at scientific data, vaccinations work, and in the words of Mr. Rogers, “Real strength has to do with helping others.”
Hannah Smith is an intern in the Section of Anthropocene Studies. Museum employees are encouraged to blog about their unique experiences and knowledge gained from working at the museum.
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