Despite the non-stop COVID-19 coverage on mainstream broadcast news during the last eight weeks, there’s at least one important COVID-related topic that the networks seem reluctant to cover: herd immunity.
Perhaps networks avoid the topic out of concern that their coverage could be interpreted by viewers as encouragement to go outside, to disregard the protection measures prescribed by the U.S. Centers for Disease Control (CDC) and to ignore draconian executive orders imposed by states and localities.
Perhaps the news networks don’t cover natural herd immunity because it would make people less fearful. After all, history has shown and continues to prove that network ratings are the highest when people are fearful and bound to their homes. CNN, for example, had record-high ratings for the first quarter of 2020, The Wall Street Journal reported on April 15:
CNN and other cable news outlets could scarcely imagine that anything could juice viewership like the 2016 U.S. presidential election and its aftermath; but ratings have soared during the pandemic, reaching levels well above those when “Russian interference” and “Mueller report” dominated the news.
CNN has averaged 2.2 million total viewers in prime time through the first week of April, more than double its viewership in the fourth quarter of 2019, and roughly 57% higher than its election-season peak, according to Nielsen data. Fox News is up nearly 50% since the end of last year to over four million viewers, increasing its lead over its two main rivals. MSNBC has seen the smallest lift. The three networks’ websites all saw big audience gains, too.
Or perhaps news broadcasters fail to educate viewers about natural herd immunity because it might harm network revenues. Television viewers are “cutting the cord” with their cable companies in increasing numbers. That means news networks are relying more and more on commercial advertising revenue for the lifeblood of their business.
Over time, drug advertisements by pharmaceutical companies have grown to represent a disturbingly disproportionate share of advertising revenue. At CNN, for example, 80 percent of its ad revenue in 2018 came from pharmaceutical companies, according to Adweek subsidiary TVNewser.
Pharmaceutical companies are currently competing to produce COVID-related testing, treatments and vaccines. Sudden natural herd immunity would render moot the need for a broad deployment of vaccines. However, there is still hope for big pharma in such a scenario. Even if the public does develop natural herd immunity, there could still be demand for pharma company products provided that the public remains unaware of their own immunity, the rate of immunity of those around them and its significance.
If the mainstream broadcast news networks educated the public about natural herd immunity and beat the drum every day for mass antibody testing the same way they did for ventilators, we would likely have greater deployment of antibody testing. With more antibody testing, we can better identify true risk and make intelligent decisions about how to move forward over time. But the media is disincentivized to do so.
To some, the very idea that news providers would conspire — either implicitly or explicitly — for the benefit of advertisers and to the detriment of the public may seem like a far-fetched theory. Some people would be dead wrong. It’s an issue that is studied at length in journalism ethics classes, using actual case studies. But I digress.
Understanding Herd Immunity
Immunity occurs when a person has antibodies to fend off a virus. These antibodies are the byproduct of exposure to the virus and recovery. Exposure can happen naturally, via human-to-human contact for example, or by vaccination with a weakened or dead virus.
Herd immunity occurs when a significant portion of a population has immunity, thereby reducing or eliminating risk to those who don’t. The percentage of the “herd” that is required to have immunity so those that don’t are protected will vary depending on the contagiousness of the virus, according to MIT Technology Review. The higher the rate of spread, the higher the rate of immunity required to protect the entire herd.
The point at which we reach herd immunity is mathematically related to the germ’s propensity to spread, expressed as its reproduction number, or R0. The R0 for the coronavirus is between 2 and 2.5, scientists estimate (pdf), meaning each infected person passes it to about two other people, absent measures to contain the contagion.
To imagine how herd immunity works, think of coronavirus cases multiplying in a susceptible population this way: 1, 2, 4, 8, 16, and so on. But if half the people are immune, half of those infections won’t ever happen, and so the spreading speed is effectively cut in two. Then, according to the Science Media Centre, the outbreak simmers along like this instead: 1, 1, 1, 1 … The outbreak is snuffed out once the infection rate is less than 1.
Herd immunity is how the human race has recovered from numerous viruses that have swept the planet. The 1918 novel influenza virus, for example, disappeared after about 50% of the affected population contracted it and recovered, Harvard University epidemiologist Marc Lipsitch told a gathering of experts on a video call.
Remember the Zika virus? Hardly anyone talks about it anymore. The mosquito-borne illness got a foothold in Brazil and created an epidemic panic in 2015 because of its link to birth abnormalities. Two years later, in 2017, there was no longer worry about it, MIT reports:
A Brazilian study found by checking blood samples that 63% of the population in the northeastern beach city of Salvador had already had exposure to Zika; the researchers speculated that herd immunity had broken that outbreak. …
Even then, vaccine makers can find themselves in a losing race with nature to see which protects the herd first. That’s in part what happened in 2017, when drug maker Sanofi quietly abandoned a Zika vaccine in development after funding dried up: there simply wasn’t much of a market any longer.
Protecting the Herd from COVID-19?
The rate of spread of COVID-19 is higher than the ordinary flu but similar to other novel influenzas, researchers say. Figures range from 50% to 80%. The simplest of models, MIT reports, gives the virus an R0 of 3, which means 66% of the population would have to be immune for the entire herd to have protection.
However, if we all remain in isolation, then younger, healthier people will not have the opportunity to develop immunity. This will put the entire population at greater risk, prolong the pandemic and make vaccinations an imperative.
“Suppressing transmission means that we won’t build up herd immunity,” Azra Ghani, the lead epidemiologist on the new model of the outbreak from Imperial College London, told MIT. The trade-off of success is “that we are driving it down to such a low level that we have to keep those [measures] in place.”
Clearly, the sound approach is to encourage younger, healthier groups to go back into their communities, back to school, back to sports and to enjoy life. This is especially true given that COVID-19 is mild for at least 96% of those infected. This number may higher as antibody testing becomes more widespread (if ever).
Until we reach herd immunity by whatever means, older and more vulnerable folks should be informed of risks, be encouraged to self-isolate, be provided with protective gear and assistance, and then be allowed to make their own choices.