Changing CDC Guidance, Communication, and Conspiracy

Science and insanity don't mix.

The evolving scientific understanding of a novel virus would be a major challenge in public health policy in normal times. We are not living in normal times.

LAT (“CDC shifts pandemic goals away from reaching herd immunity“):

Since the earliest days of the pandemic, there has been one collective goal for bringing it to an end: achieving herd immunity. That’s when so many people are immune to a virus that it runs out of potential hosts to infect, causing an outbreak to sputter out.

Many Americans embraced the novel farmyard phrase, and with it, the projection that once 70% to 80% or 85% of the population was vaccinated against COVID-19, the virus would go away and the pandemic would be over.

Now the herd is restless. And experts at the Centers for Disease Control and Prevention have set aside herd immunity as a national goal.

The prospects for meeting a clear herd-immunity target are “very complicated,” said Dr. Jefferson Jones, a medical officer on the CDC’s COVID-19 Epidemiology Task Force.

“Thinking that we’ll be able to achieve some kind of threshold where there’ll be no more transmission of infections may not be possible,” Jones acknowledged last week to members of a panel that advises the CDC on vaccines.

Vaccines have been quite effective at preventing cases of COVID-19 that lead to severe illness and death, but none has proved reliable at blocking transmission of the virus, Jones noted. Recent evidence has also made clear that the immunity provided by vaccines can wane in a matter of months.

The result is that even if vaccination were universal, the coronavirus would probably continue to spread.

“We would discourage” thinking in terms of “a strict goal,” he said.

Especially since, to actually be “universal,” we’d have to get the whole planet, not just the United States, to herd immunity. And that’s likely not going to happen anytime soon.

To Dr. Oliver Brooks, a member of the CDC’s Advisory Committee on Immunization Practices, it was a sobering new message, with potentially worrisome effects.

With just 58.5% of all Americans fully vaccinated, “we do need to increase” the uptake of COVID-19 shots, said Brooks, chief medical officer of Watts Healthcare in Los Angeles. Unfortunately, he said, Jones’ unexpected admission “almost makes you less motivated to get more people vaccinated.”

Brooks said he worries that as the CDC backs off a specific target for herd immunity, it will take the air out of efforts to run up vaccination levels.

And if public health officials stop talking about the “herd,” people may lose sight of the fact that vaccination is not just an act of personal protection but a way to protect the community.

This remains the problem with “the science” as it relates to public health. The lay public is likely to get very confused by the evolving understanding of what has always been a novel disease. And the messaging public health officials send is geared toward desired actions, not necessarily to convey the full, complex picture.

It seems perfectly reasonable to me to continue getting boosters (I got my first Wednesday) even though it may well not be the last. But I can understand why people would simply throw up their hands and say “What’s the use?!”

A public tack away from the promise of herd immunity may also further undermine the CDC’s credibility when it comes to fighting the coronavirus.

On issues ranging from the use of masks to how the virus spreads, the agency has made some dramatic about-faces over the course of the pandemic. Those reversals were prompted by new scientific discoveries about how the novel virus behaves, but they’ve also provided ample fuel for COVID-19 skeptics, especially those in conservative media.

“It’s a science-communications problem,” said Dr. John Brooks, chief medical officer for the CDC’s COVID-19 response.

It didn’t help—to say the least!—that the former President was actively downplaying the virus and pressuring the CDC to go along.

“We said, based on our experience with other diseases, that when you get up to 70% to 80%, you often get herd immunity,” he said.

But the SARS-CoV-2 virus didn’t get the memo.

“It has a lot of tricks up its sleeve, and it’s repeatedly challenged us,” he said. “It’s impossible to predict what herd immunity will be in a new pathogen until you reach herd immunity.”

Which, of course, is perfectly understandable. Making educated guesses based on known evidence and adjusting as more information comes in is what scientists do. But it’s frustrating to people looking to experts for advice and to constantly get changing, and seemingly contradictory, advice. And, again, the fact that Trump and the conservative media machine politicized all of this has exacerbated the problem geometrically.

The CDC’s new approach will reflect this uncertainty. Instead of specifying a vaccination target that promises an end to the pandemic, public health officials hope to redefine success in terms of new infections and deaths — and they’ll surmise that herd immunity has been achieved when both remain low for a sustained period.

“We want clean, easy answers, and sometimes they exist,” John Brooks said. “But on this one, we’re still learning.”

While it seems like it’s been a lot longer than that, we’re less than two years into this thing. (Technically, the first cases appear to have emerged in October 2019 but the infection cluster was not reported to the WHO, so that scientists could start working the problem, until December 31.) That we’re already at the point where we’ve vaccinated so many people is remarkable. That we haven’t fully figured out an evolving disease is not.

Beyond that, communicating complex concepts to non-experts is a challenge.

Herd immunity was never as simple as many Americans made it out to be, said Kathleen Hall Jamieson, director of the Annenberg Public Policy Center at the University of Pennsylvania and an expert on the challenges of communicating science to increasingly skeptical — and often conspiracy-minded — citizens.

It’s an idea that emerged about a century ago from the field of livestock medicine. Epidemiologists now calculate it with a standard equation. But like many tools that model a complex process with math, it makes some simplifying assumptions.

For instance, it assumes an unrealistic uniformity in the behavior of individuals and groups, and in the virus’ ability to spread from person to person.

So it doesn’t reflect the diversity of population density, living arrangements, transportation patterns and social interactions that makes Los Angeles County, for instance, so different from Boise County, Idaho. Nor does it account for the fact that Boise County, where less than 35% of adults are fully vaccinated, gets no protection from L.A. County’s 73% vaccination rate among adults.

“Humans are not a herd,” Jamieson said.

Public health leaders would have been better served by framing their vaccination campaigns around the need for “community immunity,” she said. That would have gotten people to think in more local terms — the ones that really matter when it comes to a person’s risk of infection, she added.

But, again, this assumes that the CDC and other public health officials were working in a normal world, where the only obstacles are evolving expert understanding and the difficulty of communicating with the general public. That Trump and company worked so hard to undermine the messaging simply can’t be overemphasized.

Interestingly, Jamieson recently published a report in Nature Human Behavior titled “How conspiracists exploited COVID-19 science.” Some representative excerpts:

Instead of envisioning an untidy world filled with randomness, unintended consequences, innocent action gone awry and new evidence, conspiracists envision one that is inhabited by powerful individuals who conceal malign activities and intent. The fluid nature of emergent science provides fuel for conspiracy theorists who offer certainty in place of the provisional, sometimes-updated statements of health experts. At the same time, conspiracy proponents question the trustworthiness and motives of those in the federal agencies, philanthropic institutions and pharmaceutical companies who fund basic research and develop, deliver and, in the case of some of the federal agencies, regulate public access to medical treatments, including vaccines.


Statements and updates by Dr Fauci about mask wearing and hydroxychloroquine were among those used by conspiracy theorists during the pandemic. As indications accumulated that individuals without symptoms can transmit SARS-CoV-2, the Centers for Disease Control and Prevention (CDC), the Surgeon General and Dr Fauci did an about-face on the advisability of routine mask wearing in public settings. When randomized, placebo-controlled clinical trials found that hydroxychloroquine was ineffective as a COVID-19 treatment, Dr Fauci’s agnosticism about its value shifted to opposition. He was not alone. The US Food and Drug Administration (FDA) also withdrew its Emergency Use Authorization of it. “Much of what Fauci said about this virus, the drugs that could treat it, and the measures that could be taken to slow the spread was untrue”, said Fox News’s Laura Ingraham on the 2 June 2021, “He knew it was untrue”. After listing “cruise ships, masks, lockdowns, the origins of COVID-19, [and] the models and projections” as topics on which Dr Fauci had been “wrong”, on 2 June 2021, Fox News’s Sean Hannity asked “What did Dr Fauci know and [w]hen did Dr Fauci know it, and was he engaged in some kind of scientific cover-up?”.

For conspiracists of an ideologically conservative bent, some of conclusions of the science community did not reflect science but instead a desire to undercut Trump’s re-election prospects. “The partisan Democrats, the conjugal media, and the scientists, the deep state scientists want America sick through November”, alleged Michael Caputo, who was appointed by Trump as assistant health and human services secretary for public affairs. Among the decisions at issue were whether the whole population other than essential workers needed to be ‘locked down’ to ‘bend the curve’, the speed with which the economy should be re-opened after the ‘lockdown’ and when a vaccine would be available for distribution. The insistence of experts such as Dr Fauci that decisions about the use of proposed treatments such as hydroxychloroquine and convalescent plasma, and the authorization of a COVID-19 vaccine, should await high-quality clinical trial data was also interpreted as being anti-Trump in intent. “The deep state, or whoever, over at the FDA is making it very difficult for drug companies to get people in order to test the vaccines and therapeutics. Obviously, they are hoping to delay the answer until after November 3rd”, tweeted President Trump on 22 August 2020.


Into this brew, conspiracists add conjecture (“maybe [the COVID-19 vaccine] doesn’t work and they’re simply not telling you that”5) and insinuations that are intended to identify a conspirator’s motive (for example, that Dr Fauci is a registered Democrat6, a past CEO of Moderna7 and a vaccine shareholder8). Such factors are interlaced to warrant context-specific conspiracy theories (for example, that the FDA is covering up the fact that the mRNA vaccines cause serious side effects and death9; or that, in league with ‘Big Pharma’, Dr Fauci mandates vaccines from which he, Big Pharma, the Gates Foundation, Chan-Zuckerberg, WHO, CDC and the Chinese Communist Party benefit10).

Personal greed is one ascribed motive, and sociopathy or lust for power, glory and knowledge are others. Accordingly, one theory accuses Dr Fauci of opposing the approval of hydroxychloroquine — a drug that Trump cast as a possible “game changer”11 — because Dr Fauci wanted the virus to spread until a vaccine could be developed and named after him12. On another front, by terming the nation’s leading infectious disease specialist the ‘father of the virus’, conspiracists assumed the motive explored in Mary Shelley’s Frankenstein — an arrogant search for knowledge unmindful of the risks or consequences. The meme ‘Fauci Lied. Millions Died’13 capsulizes the conspiracy assertion that by denying that a US$600,000 National Institutes of Health (NIH) subaward from EcoHealth Alliance to the Wuhan Institute of Virology14 involved gain-of-function research, Dr Fauci and compatriots such as NIH director Dr Francis Collins are covering up (that is, ‘Fauci Lied’) the supposed reality that the resulting explorations created SARS-CoV-2 and with it the pandemic (that is, ‘Millions Died’).

And those aren’t even the craziest bits.

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James Joyner
About James Joyner
James Joyner is Professor and Department Head of Security Studies at Marine Corps University's Command and Staff College. He's a former Army officer and Desert Storm veteran. Views expressed here are his own. Follow James on Twitter @DrJJoyner.


  1. Scott says:

    Herd immunity is roughly represented by the equation 1-1/R0. The original R0 (reproduction number) for COVID-19 was estimated at 3 which gave a herd immunity target of .66 of the population which seems doable. The delta variant upped the R0 to 6 which raised the herd immunity target to about 84%. Given that the under 18 population was about 20-25%, herd immunity was not achievable without being able to vaccinate pretty much everyone. But, as indicated, the changing goalposts are hard to communicate.

    OTOH, measles has a R0 of 12 which implies herd target of 92%. And we pretty much have eliminated (and continue to eliminate measles).

  2. Modulo Myself says:

    But when it comes to health human beings are herd animals. There is nothing that makes you less of an individual and more of a universal human blob than feeling sick. We all basically feel sick the same way and we all feel better the same way.

    We just have a system where universal connections have been replaced by statistics, and we are so used to that form of communication, where everything is a thought experiment set up by experts, that we don’t realize what it has replaced.

    Honestly, if sharing were invented and rolled out in 2020 it would have been called a Marxist plot and parents would be screaming about how it’s being taught in schools.

  3. Kathy says:


    SARS-CoV-2 is a very inclusive type of pathogen. It’s been found in great proportion among white-tailed deer in the wild, and in minks in fur farms. This means the potential reservoirs for it, after it finally burns itself out among H. sapiens, is huge. Not unlike flu, which likes some of our domesticated animals.

    Expect variants to evolve without us as well as within us. We’re in for a long association with it.

    As to the main point of the post, two things of note:

    1) People suck at updating their internal information. they tend to stick with the first thing they hear, see, or read no matter how many corrections are provided and even when they have no inherent interest for retaining the first and erroneous info.

    2) The vaccines were designed based on the original strain of the trump virus, and tested largely on that and the Alpha variant. It proved very effective against them, though we had to wait months afterwards to find out about waning immunity.

    Had they been tested against Delta, the results would have been different. Even so, the vaccines remain very effective against Delta, especially as regards protection against severe disease requiring hospitalization, not to mention death. they get even better with boosters.

    I expect a variant-specific vaccine next year, or a polyvalent vaccine.

  4. Gustopher says:


    SARS-CoV-2 is a very inclusive type of pathogen. It’s been found in great proportion among white-tailed deer in the wild, and in minks in fur farms.

    The deer in the wild is something that surprised me when I heard (herd?) about it, as it brings up the question of how it spread. Deer tend to be outside, where there’s lots of ventilation, and while they may not keep socially distant from each other, they do keep socially distant from people.

    The only conclusion that I can make is a scene out of The Far Side, where there is a deer in a living room, standing on his/her hind legs, having tea with a person.

    Keep in mind that this is not a request for someone to explain any other method of transmission to deer. Let’s all just agree that this is the most likely scenario, and that anything involving, fleas, ticks, hunters being really close, deer licking doorknobs, etc, just won’t be as charming.

  5. Mikey says:

    vaccination is not just an act of personal protection but a way to protect the community

    I’ll submit that roughly half of Americans don’t give a frog’s fat ass about protecting the community.

  6. Joe says:

    @barbintheboonies: No, actually this is just a conspiracy theory. Two instances of post hoc, propter hoc turned into “obvious causation.”

  7. Erik says:

    I’ve been using a sports analogy when I try to explain this to some people: while it might make sense to script the first series of plays for a football game [pre-planned epidemic planning], after that you have to adjust your play calls on a regular bases to respond to and take advantage of the way the other team [virus] is playing. I’ve had some success with it

  8. Kathy says:

    OMG, it’s the zombie apocalypse. the brain-dead are rising and posting at OTB!

  9. gVOR08 says:

    Especially since, to actually be “universal,” we’d have to get the whole planet, not just the United States, to herd immunity.

    I see Kathy beat me to adding, “including White-Tailed Deer.” In any case “herd immunity” is a matter of degree, not a fixed number. If all the hesitant GOPs got vaccinated, we’d be a lot closer to it.

    I thought it was John Stuart Mill who said,

    When the facts change, I change my mind. What do you do sir?

    but apparently it’s attributed to various people. It’s a valid question anyway. People crave the certainty and apparent simplicity of religion, which exists only because religion never offers falsifiable statements. Science has to deal with the real world and the real world is messy.

  10. CSK says:

    This is going to be stretched to the point that if an 80-year-old dies one year after receiving the vaccine, anti-vaxxers will be saying that the death was caused by the vaccine.

    An irony: Last year, the anti-vaxxers were tellimg us that people who died of Covid had really died of strokes or heart attacks or some other ailment, and were being listed as Covid deaths to fraudulently up the total of Covid fatalities. This year we’re hearing from the anti-vaxxers that people who died of heart attacks or strokes actually died from the vaccine.

    Which is it?

  11. Mikey says:


    This comment tells us a lot about you, but nothing good.

  12. Kathy says:


    Keep in mind that this is not a request for someone to explain any other method of transmission to deer.

    And this is not an explanation of transmission among deer.

    It is a reminder that transmission outdoors is less likely, not impossible. Likewise transmission indoors with good ventilation. Or in airplanes, which have excellent ventilation and HEPA filters, in addition with mask requirements.

  13. steve says:

    “Today I hear of a healthy young man, an athlete, who got his shots and soon after his heart rate went from 30-70 range to sustained 180.”

    I ran a shot clinic as a corpsman and as a doc I am very hands on. I volunteered and gave thousands of vaccine shots. This sounds like the guy got vagal after his first shot, happens a lot with young men especially very fit/very macho guys. Saw it happen lots with special forces guys. In lay persons terms it means they drop their heart rate. We usually treat by ignoring until it goes away or by giving an anti-cholinergic to increase heart rate (atropine, glycol). In response it is not unusual to see them get pretty tachy and then you have to also treat that. All of this is in response to the needle, not what is injected.


  14. Mu Yixiao says:


    I got my second shot in April. Then in June, I was in pain from a congenital deformity of the glenoid, a torn labrum, and osteo-arthritic degradation of the humoral head!

    The vaccine damaged my shoulder!!

  15. Scott says:


    post hoc, propter hoc

    Actually, I learned that in High School… Public High School… You know…Where the common people go.

    us common people

    I just want people to use a little bit of common sense.

    It is hard to go through life shouldering festering grievance where you think you didn’t get a fair shake and life didn’t turn out the way you think it should. And then blame everyone else for where you ended up.

  16. Erik says:

    @barbintheboonies: honestly asking: for starters, what have you done to validate that this story of the athlete is true?

  17. CSK says:

    @Mu Yixiao:
    Don’t laugh. A 43-year-old chef, Gurpareet Bains, died of a heart attack, and all the the crazies at want to know is: “When did he get vaccinated?”

  18. wr says:

    @barbintheboonies: “I have not a clue what you just said, but I am sure it is liberal double talk, to show you went to some school to say things that us common people don’t understand or care to.”

    What you call “liberal double talk” the rest of the western world calls “Latin.” And there are plenty of common people who actually know something about language. It’s stupid people who don’t understand or care to.

  19. just nutha says:

    @Scott: Not a doctor, so account for that in my question, too, but isn’t part of the trick with measles that the vaccine stops you from getting measles rather than simply keeping you from getting really sick from them? One of the no sells with Covid-19 jabs has been (or at least claimed) that if you can still get sick from Covid-19, there’s less point in getting jabbed. (And yes, I understand that’s a stupid argument, nevertheless…)

  20. just nutha says:

    @barbintheboonies: ” If you believe you are safe why do you GAD what others do or don’t do?”

    For some of us, G(ing)AD is about the quaint–albeit socialist/Marxist/Anarchist/Fascist–notion that when others are not safe, our relative safety declines also. But thank you all the same for reinforcing Mikey’s thought:

    I’ll submit that roughly half of Americans don’t give a frog’s fat ass about protecting the community.

    And take whatever comfort there is in knowing that, at least, you represent the majority. (I’m less generous in my opinions of society than Mikey. 🙁 )

  21. Scott says:

    @just nutha:

    From the CDC:

    Very few people—about three out of 100—who get two doses of measles vaccine will still get measles if exposed to the virus. Experts aren’t sure why. It could be that their immune systems didn’t respond as well as they should have to the vaccine. But the good news is, fully vaccinated people who get measles seem more likely to have a milder illness. And fully vaccinated people seem also less likely to spread the disease to other people, including people who can’t get vaccinated because they are too young or have weakened immune systems.

  22. just nutha says:

    @Scott: I learned it in high school, too, but I have to admit that I went to a big city high school, so my experience may be unique (as in one-of-a-kind).

  23. Mikey says:

    @just nutha:

    (I’m less generous in my opinions of society than Mikey. )

    I’m nothing if not an optimist.

  24. dazedandconfused says:

    Well, I agree with James, but will opine that honest expressions of uncertainty (which I prefer) will also prove excellent fodder for those who love panic. They will instinctively realize they can assert their “facts” just as well in that environment. Perhaps even better initially, as strong assertions with even less contradictions to counter them. They will be less well positioned for the long-game though.

    White’s Law

  25. Kathy says:

    @just nutha:

    The immune system is a complicated adaptation, mixed with the complicated adaptations the pathogens bring along.

    What seems to happen with SARS-CoV-2 and vaccines, is that the virus has scant chance to successfully establish itself in a person who still has the high levels of antibodies produced in response to the vaccine.

    As these levels drop off, it has a better chance. Ergo, breakthrough infections are more likely months after the second dose, absent boosters. This is especially so with the Delta variant, which transmits more easily and apparently reproduces more effectively.

    Immunity is not only a matter of antibodies. There are also T-cells* in various rolls. Some aid B-cells in producing antibodies, others kill infected cells, and there’s more. Best of all, the vaccines produce memory T-cells and memory B-cells. This means even after your antibody levels drop to nothing, the immune system will recognize the SARS-CoV-2 spike protein and make more B-cells to make more antibodies, plus more types of T-cells to aid in the fight. Perhaps this response won’t keep you from getting infected, but it is your best defense against getting severely ill.

    Boosters get the immune system process re-started, thus producing more fresh antibodies, thus giving you a better chance to avoid infection.

    BTW, if you do get ill or test positive after being vaccinated, ask about monoclonal antibodies or the Merck COVID pill. Ask loudly and insist on such treatment.Apparently many physicians and hospitals are not up to speed about these. The Pfizer pill, I think, isn’t out in circulation yet.

    * T-cells get their name because they are produced in the thymus. B-cells are produced in the bone marrow, but get their name from an organ birds use to produce them, because they were first discovered there. This is the bursa of Fabricius.

  26. Mimai says:

    Public health leaders would have been better served by framing their vaccination campaigns around the need for “community immunity,” she said. That would have gotten people to think in more local terms — the ones that really matter when it comes to a person’s risk of infection, she added.

    This is a strange contention. The public doesn’t do nuance, which makes public health communication especially difficult. And substituting “herd” for “community” is supposed to have an effect?

    If I were being uncharitable (which I’m trying not to be, though this parenthetical suggests otherwise), I might say that Jamieson is too interested in communicating her cleverness.

  27. Mimai says:

    @Mimai: ugh… that should read substituting “community” for “herd”

  28. Jax says:

    @Mimai: It may or may not be a “focus group” that leads back to it. Are you, yourself, more inclined to show up to a herd cleanup or a community cleanup? Going back generations, we’re inclined to understand “herd immunity”, but now that it’s been made anathema, what other words can we use, from a “public health” standpoint?

    The times are definitely changing.

  29. Mimai says:

    @Jax: Oh, I’m definitely more likely to go to a community cleanup. But that’s because a herd cleanup sounds like grunt work on a farm/ranch.

    It’s also important to note that I am not the median resident who is the target of such messaging.

    I agree that the times (and language) are changing. My skepticism is focused on whether a subtle change from “herd” to “community” is going to have any measurable effect on public health behavior.

  30. Jax says:

    @Mimai: It might. I see a lot more people willing to do things for their community than for what they call “the herd”. It’s the same damn thing, but whatever kind of linguistics we gotta use to spread the love and keep them alive, even when they wouldn’t do the same for us…..

    Hearing somebody wish they’d never gotten vaccinated, for instance…..dang. Maybe we shouldn’t have wasted a shot on her. There’s plenty of people elsewhere happy to take hers.

  31. Jax says:

    @Mimai: de Stijl’s not usually around on Friday’s, so I’ll post this for you. What do you think? I think they should’ve lain off the cartoon stuff and focused more on Danny rockin that cello for the drums! But sure, it’s a new take on one of my favorite classics.

  32. de stijl says:


    Modern day Americans are utterly incapable of surviving outside of the community.

    Wanna survive off the grid? You gotta buy a crap ton of store bought stuff to do it.

    We are community. We fall and rise by it. Rise is preferred.

  33. de stijl says:


    I’m here. Just late.

  34. Mimai says:

    @Jax: I missed this last night. Had just returned from some live music myself. As for the link, I’m hard pressed to take issue with a banjo centric tune (and invasion). Fun cover. Might have benefitted from a tenor guitar. But these dudes are pros, so who am I to nitpick.

    ps, speaking of herds, I’ll be working some dairies in a couple weeks. Vacation!

  35. James Joyner says:

    @Jax: @Mimai: I’m barely familiar with the band with “In Hell I’ll be in Good Company” the only other tune of theirs I’m familiar with. But I’m a fan of the “bluegrass takes on popular music” genre.

  36. Matt Bernius says:

    @James Joyner: Have you heard the good news of Hayseed Dixie?

  37. Neil Hudelson says:

    @James Joyner:

    I started a playlist of bluegrass covers on Spotify. I’ll find it, clean it up a bit, and post it when I’m not at the airport, and in an open thread so as not to hijack.

    I’m on the way back after 5 days with two toddlers doing that parental right of passage, ̶F̶u̶l̶a̶n̶i̶ ̶W̶h̶i̶p̶ ̶B̶a̶t̶t̶l̶e̶s̶ ̶ visiting the Most Magical Place on Earth.

    The good news is I’m only mostly dead. There’s a big difference between all the way dead and mostly dead.