Tag Archives: Breakthrough Infections

Vagaries of Vaccine Efficacy

23 Sunday Jan 2022

Posted by in Coronavirus, Vaccinations

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There should never have been any doubt that vaccines would not stop you from “catching” the coronavirus. Vaccines cannot stop virus particles from lodging in your nose or your eyeballs. The vaccines act to prime the immune system against the virus, but no immune response is instantaneous. In other words, if you aren’t first “infected”, antibodies don’t do anything! A virus may replicate for at least a brief time, and it is therefore possible for a vaccinated individual to carry the virus and even pass it along to others. The Omicron variant has proven that beyond a shadow of a doubt, though the wave appears to be peaking in most of the U.S. and has peaked already in a few states, mostly in the northeast.

I grant that the confusion over “catching” the virus stems from an imprecision in our way of speaking about contracting “bugs”. Usually we don’t say we “caught” one unless it actually makes us feel a bit off. We come into intimate contact with many more bugs than that. The effects are often so mild that we either don’t notice or brush it off without mention. But when it comes to pathogens like Covid and discussions of vaccine efficacy (VE), it’s obviously useful to remember the distinction between infections, on the one hand, and symptomatic infections on the other.

Cases Are the Wrong Focus

Unless calibrated by seroprevalence data, these studies are not based on proper estimates of infections in the population. Asymptomatic people are much less likely to get tested, and vaccinated individuals who are infected are either much more likely to be asymptomatic or the test might not detect the weak presence of a virus at all. VE based on detected infections is essentially meaningless unless testing is universal.

We are bombarded by studies (and analyses like the one here) alleging that VE should be judged on the reduction in infections among the vaccinated. The likelihood of a detected infection by vaccination status is simply the wrong way to measure of VE. It’s not so much the direction of bias in measured VE, however. The mere presence of cases among the vaccinated has been sufficient to inflame anti-vax sentiment, especially cases detected in mandatory tests at hospitals, where the infections are often incidental to the primary cause of admission.

The typical evolution of a novel virus is further reason to dismiss case numbers as a basis for measuring VE. Mutations create new variants in ways that usually promote the continuing survival of the lineage. Subsequent variants tend to be more transmissible and less deadly to their hosts. Thus, given a certain “true” degree of VE, so-called breakthrough infections among the vaccinated are even more likely to be asymptomatic and less likely to be tested and/or detected.

There is the matter of immune escape or evasion, however, which means that sometimes a virus mutates in ways that get around natural or vaccine-induced immune responses. While such a variant is likely to be less dangerous to unvaccinated hosts, more cases among the vaccinated will turn up. That should not be interpreted as a deterioration in VE, however, because detected infections are still the wrong measure. Instead, the fundamental meaning of VE is a lower virulence or severity of a variant in vaccinated individuals than in unvaccinated individuals.

Interestingly, to digress briefly, while immune escape has been discussed in connection with Omicron, that variant’s viral ancestors may have predated even the original Covid strain released from the Wuhan lab! It is a fascinating mystery.

Virulence

In fact, vaccines have reduced the virulence of Covid infections, and the evidence is overwhelming. See here for a CDC report. The chart below is Swiss data, followed by a “handy” report from Wisconsin:

From the standpoint of virulence, there are other kinds of misguided comparisons to watch out for: these involve vaxed and unvaxed patients with specific outcomes, like the left side of the graphic at the top of this post (credit to Twitter poster aparachick). This thread has an excellent discussion of the misconception inherent in the claim that vaccines haven’t reduced severity: the focus is on the wrong conditional probability (again, like the left side of the graphic). Getting that wrong can lead to highly inaccurate conclusions when the sizes of the two key groups, hospitalizations and vaccinated individuals in this case, are greatly different.

Bumbled Messaging

The misunderstandings about VE are just one of many terrible failures of public health authorities over the course of the pandemic. There seems to have been fundamental miscommunication by the vaccine manufacturers and many others in the epidemiological community about what vaccines can and cannot do.

Another example is the apparent effort to downplay the importance of natural immunity, which is far more protective than vaccines. This looks suspiciously like a willful effort to push the narrative that universal vaccination as the only valid course for ending the pandemic. Even worse, the omission was helpful to those attempting to justify the tyranny of vaccine mandates.

Waning Efficacy

It should be noted that the efficacy of vaccines will wane over time. This phenomenon has been measured by the presence of antibodies, which is a valid measure of one aspect of VE over time. However, immune responses are more deeply embedded in the human body: so-called T-cells carry messages alerting so-called B-cells to the presence of viral “invaders”. The B-cells then produce new antibodies specific to characteristics of the interloping pathogen. Thus, these cells can function as a kind of “memory” allowing the immune system to mount a fresh antibody defense to a repeat or similar infection. The reports on waning antibodies primarily in vaccinated but uninfected individuals do not and cannot account for this deeper process.

Conclusion

Vaccines don’t necessarily reduce the likelihood of infection or even the spread of the virus, but they absolutely limit virulence. That’s why Jay Bhattacharya, one of the authors of The Great Barrington Declaration, says the vaccines provide a private benefit, but only a limited public benefit. Yet too often we see VE measured by the number of infections detected, and vaccine mandates are still motivated in part by the idea that vaccines offer protection to others. They might do that only to the extent that infections are less severe and clear-up more quickly.

In Praise of Voluntary Vaccination

31 Tuesday Aug 2021

Posted by in Coronavirus, Vaccinations

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I was vaccinated in March and early April and I’m damn glad to have done it. I have certain co-morbidities, and I’m of an age at which contracting COVID seems like a very bad idea, I felt a little run-down on the day after my second jab, but that was my only side effect, notwithstanding the unending litany of antivax hysterics to which we’ve all been subjected (even on certain sites to which I contribute).

Freedom Without Misinformation

In the context of the pandemic, it’s important to take a stand for liberty. In that spirit, I oppose the imposition of mandates requiring face masks and vaccinations against COVID. Furthermore, vaccination is at best unnecessary for those having acquired immunity from infection and for those at low risk, especially children. In fact, the younger, healthier, and fitter you are, the less important it is to be vaccinated.

It’s disappointing, however, to see completely innumerate people cite statistics purporting to show that COVID-19 vaccines are deadly or even particularly dangerous to those lacking contra-indications. Far worse, and far more idiotic, is to suggest that a conspiracy is afoot to kill large numbers of people via vaccination! I’m truly embarrassed to hear individuals who otherwise share my libertarian ideals say such irresponsible bullshit.

While the COVID vaccines seem to have more frequent side effects than earlier vaccines, they are not particularly risky. I’ll discuss the safety of the COVID vaccines in what follows. Even minuscule risks are unacceptable to some individuals, which of course is their right. However, others find these risks acceptable considering the far greater dangers posed by the early strains of COVID and even the more recent but less deadly Delta variant.

Unverified Adverse Events

The vaccine scaremongers often quote statistics from the CDC’s Vaccine Adverse Reporting Events System (VAERS). Here’s a disclaimer about the system from the CDC’s web site:

“Healthcare providers, vaccine manufacturers, and the public can submit reports to VAERS. While very important in monitoring vaccine safety, VAERS reports alone cannot be used to determine if a vaccine caused or contributed to an adverse event or illness. The reports may contain information that is incomplete, inaccurate, coincidental, or unverifiable.”

All kinds of reports are submitted alleging adverse events. For example, one observer cites the following reports from the system:

The link above refers to the following report as “Hulk Syndrome”, which was alleged to have been a side effect of the MMR vaccine:

Finally, we have this report related to the Pfizer COVID vaccine:

In case that’s hard to read, it claims that a COVID vaccine caused a third arm to grow from the reporting individual’s forehead, which constantly slaps him or her while trying to sleep. This report is a case of wonderful sarcasm, but it was submitted to VAERS! The real lesson is that the VAERS system collects many unverified accounts of side effects, so the aggregate counts of adverse events are not reliable, even by the CDC’s admission.

A More Sober Risk Assessment

Therefore, the VAERS system has obvious limitations. But even stipulating the use of VAERS reports, the risks of the COVID vaccines are vanishingly low. For example, roughly 198 million people in the U.S. have received at least one dose of a vaccine. As of last week, there had been about 13,600 reports of post-vaccination death in VAERS. The raw number is very high, and I don’t wish to minimize the seriousness of those losses. Nevertheless, if those deaths were all attributable to vaccination, and that is a BIG “if”, the risk of death from vaccination to-date is just 0.007%. That is seven thousandth of 1%. 

To put those VAERS deaths into perspective, I should first add the caveat that I am highly skeptical of the COVID case and death statistics. Nevertheless, let’s take the official U.S. COVID death toll of 646,000 at face value. I’m also treating reported vaccine deaths from VAERS at face value, which is a huge stretch. So, we have COVID mortality of 0.2% of the U.S. population, which is more than 28 times the risk of death from vaccination. I grant you the risk posed by COVID is lower going forward than in the past, which is due both to vaccinations and the declining virulence of the virus itself.

There are a range of vaccine side effects reported in VAERS, from pain near the injection site to such alarming conditions as anaphylaxis, Bell’s Palsy, and myocarditis/pericarditis. VAERS would attribute over 54,000 hospitalizations to the vaccines, a rate of 3 hundredths of one percent of those receiving at least one dose. Like COVID deaths, the number of COVID hospitalizations is likely inflated. Still, at 1.9% of the U.S. population, the risk of hospitalization from COVID is 68 times that of hospitalization from vaccine side effects reported in VAERS.

A large share of VAERS reports, covering all adverse events, are from middle aged individuals. It’s unclear how concentrated that reporting is among those with co-morbidities, including obesity, but I suspect they are heavily represented.

Coincidental Events

Perhaps less obvious is that many sincere reports to VAERS from both the public and health care providers represent coincidental events. A number of states have given heavy vaccine priority to the elderly and those with co-morbidities, and demand from those groups has been disproportionate in any case. Most of the VAERS-reported deaths also happen to be among the elderly and co-morbids.

For example, more than 38% of VAERS death reports come from the 80+ age cohort, accounting for roughly 5,200 deaths. That’s four hundredths of one percent of the 12.9 million people of ages 80+ in the U.S., most of whom have been vaccinated. Well over 1.2 million 80+ year-olds can be expected to die each year under normal circumstances. That a few would occur within days, weeks, or months of a vaccination should be expected. Furthermore, it would not be surprising, given the controversy surrounding vaccines and the suggestive power of antivax propaganda, for families or some caregivers to imagine a connection between vaccination and subsequent death. File a report! Who knows? Perhaps a class action award might be in it someday.

This is not to deny that a small number of individuals could be in such weakened states, or perhaps have unknown vulnerabilities, that the vaccines have catastrophic consequences. No doubt there are a few deaths precipitated by COVID vaccines in combination with other conditions. However, a large share of the deaths reported to VAERS are likely to have been coincidental. Likewise, people develop conditions all the time… sore joints, rashes, coughs, and headaches. It runs the gamut. Some of the VAERS reports of a less serious nature are undoubtedly coincidental, and perhaps some are due to the vivid imaginations of a subset of those having consented to the vaccine with great reluctance.

What Kills and What Doesn’t

Everything comes with a risk, and tradeoffs between risks must be balanced. The COVID pandemic was deadly, and I’ll be the first to admit that I underestimated its potential to kill. However, its deadliness was magnified by the non-pharmaceutical interventions imposed in many jurisdictions. Lockdowns and closures took a massive toll on the health of the population, cutting short many lives due to economic and personal despair as well as deferred and cancelled health care. While those interventions were deadly, I do not believe that kind of harm was intended. I do suspect the concomitant assault on liberty was welcomed in certain circles.

There are certainly downsides to the COVID vaccines. There have been more side effects and deaths than have ever been reported relative to earlier vaccines. It’s also a shame that public health authorities refuse to recognize the superior effects of natural immunity and the heightened risk of vaccinations to those with prior infections. And it’s a travesty that “vaccine passports” are now being demanded for various forms of travel, entertainment, and entry to some places of business. Despite these issues, it’s blatantly false to assert that the vaccines are generally harmful. Many more of the remaining vaccine-hesitant can benefit from vaccination. Let’s advocate for better assessments of risk by age and co-morbidity, and simply avoid the vaccines if that is your preference.

Addendum: I just came across this nice piece entitled “A Statistical Analysis of COVID-19 Breakthrough Infections and Deaths“. I thought I should share the link in case anyone supposes that so-called breakthrough infections somehow invalidate some of the comparisons I made above. This chart is particularly revealing:

Herd Immunity To Public Health Bullshitters and To COVID

16 Monday Aug 2021

Posted by in Coronavirus, Herd Immunity, Uncategorized

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My last post had a simple message about the meaning of immunity: you won’t get very sick or die from an infection to which you are immune, including COVID-19. Like any other airborne virus, that does NOT mean you won’t get it lodged in your eyeballs, sinuses, throat, or lungs. If you do, you are likely to test positive, though your immunity means the “case” is likely to be inconsequential.

As noted in that last post, we’ve seen increasing COVID case counts with the so-called Delta variant, which is more highly transmissible than earlier variants. (This has been abetted by an uncontrolled southern border as well.) However, as we’d expect with a higher level of immunity in the population, the average severity of these cases is low relative to last year’s COVID waves. But then I saw this article in ScienceAlert quoting Sir Andrew Pollard, a scientist affiliated AstraZeneca and the University of Oxford. He says with Delta, herd immunity “is not a possibility” — everyone will get it.

Maybe everyone will, but that doesn’t mean everyone will get sick. His statement raises an obvious question about the meaning of herd immunity. If our working definition of the term is that the virus simply disappears, then Pollard is correct: we know that COVID is endemic. But the only virus that we’ve ever completely eradicated is polio. Would Pollard say we’ve failed to achieve herd immunity against all other viruses? I doubt it. Endemicity and herd immunity are not mutually exclusive. The key to herd immunity is whether a virus does or does not remain a threat to the health of the population generally.

Active COVID infections will be relatively short-lived in individuals with “immunity”. Moreover, viral loads tend to be lower in immune individuals who happen to get infected. Therefore, the “infected immune” have less time and less virus with which to infect others. That creates resistance to further contagion and contributes to what we know as herd immunity. While immune individuals can “catch” the virus, they won’t get sick. Likewise, a large proportion of the herd can be immune and still catch the virus without getting sick. That is herd immunity.

One open and controversial question is whether uninfected individuals will require frequent revaccination to maintain their immunity. A further qualification has to do with asymptomatic breakthrough infections. Those individuals won’t see any reason to quarantine, and they may unwittingly transmit the virus.

I also acknowledge that the concept of herd immunity is often discussed strictly in terms of transmission, or rather its failure. The more contagious a new virus, like the Delta variant, the more difficult it is to achieve herd immunity. Models predicting low herd immunity thresholds due to heterogeneity in the population are predicated on a given level of transmissibility. Those thresholds would be correspondingly higher given greater transmissibility.

A prominent scientist quoted in this article is Paul Hunter of the University of East Anglia. After backing-up Pollard’s dubious take on herd immunity, Hunter drops this bit of real wisdom:

“We need to move away from reporting infections to actually reporting the number of people who are ill. Otherwise we are going to be frightening ourselves with very high numbers that don’t translate into disease burden.”

Here, here! Ultimately, immunity has to do with the ability of our immune systems to fight infections. Vaccinations, acquired immunity from infections, and pre-existing immunity all reduce the severity of later infections. They are associated with reductions in transmission, but those immune responses are more basic to herd immunity than transmissability alone. Herd immunity does not mean that severe cases will never occur. In fact, more muted seasonal waves will come and go, inflicting illness on a limited number of vulnerables, but most people can live their lives normally while viral reproduction is contained. Herd immunity!

Sadly, we’re getting accustomed to hearing misstatements and bad information from public health officials on everything from mask mandates, lockdowns, and school closings to hospital capacity and vaccine hesitancy. Dr. Pollard’s latest musing is not unique in that respect. It’s almost as if these “experts” have become victims of their own flawed risk assessments insofar as their waning appeal to “the herd” is concerned. Professor Hunter’s follow-up is refreshing, however. Public health agencies should quit reporting case counts and instead report only patients who present serious symptoms, COVID ER visits, or hospitalizations.

Effective Immunity Means IF YOU CATCH IT, You Won’t Get Sick

12 Thursday Aug 2021

Posted by in Coronavirus, Uncategorized, Vaccinations

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Listen very carefully: immunity does NOT mean you won’t get COVID, though an infection is less likely. Immunity simply means your immune system will be capable of dealing with an infection successfully. This is true whether the immunity is a product of vaccination or a prior infection. Immunity means you are unlikely to have worse than mild symptoms, and you are very unlikely to be hospitalized. (My disclaimer: I am opposed to vaccine mandates, but vaccination is a good idea if you’ve never been infected.)

I emphasize this because the recent growth in case numbers has prompted all sorts of nonsensical reactions. People say, “See? The vaccines don’t work!” That is a brazenly stupid response to the facts. Even more dimwitted are claims that the vaccines are killing everyone! Yes, there are usually side effects, and the jabs carry a risk of serious complications, but it is minuscule.

Vaccine Efficacy

Right out of the gate, we must recognize that our PCR testing protocol is far too sensitive to viral remnants, so the current surge in cases is probably exaggerated by false positives, as was true last year. Second, if a large share of the population is vaccinated, then vaccinated individuals will almost certainly account for a large share of infected individuals even if they have a lower likelihood of being infected. It’s simple math, as this explanation of base rate bias shows. In fact, according to the article at the link:

“… vaccination confers an eightfold reduction in the risk of getting infected in the first place; a 25-fold reduction in risk of getting hospitalized; and a 25-fold reduction in the risk for death.”

The upshot is that if you are vaccinated, or if you have acquired immunity from previous exposure, or if you have pre-existing immunity from contact with an earlier COVID strain, you can still “catch” the virus AND you can still spread it. Both are less likely, and you don’t have as much to worry about for your own health as those having no immunity.

As for overall vaccine efficacy in preventing death, here are numbers from the UK, courtesy of Phil Kerpen:

The vertical axis is a log scale, so each successive gridline is a fatality rate 100x as large as the one below it. Obviously, as the chart title asserts, the “vaccines have made COVID-19 far less lethal.” Also, at the bottom, see the information on fatality among children under age 18: it is almost zero! This reveals the absurdity of claims that children must be masked for schools to reopen! In any case, masks offer little protection to anyone against a virus that spreads via fine aerosols. Nevertheless, many school officials are pushing unnecessary but politically expedient masking policies

Delta

Ah, but we have the so-called Delta variant, which is now dominant and said to be far more transmissible than earlier variants. Yet the Delta variant is not as dangerous as earlier strains, as this UK report demonstrates. Delta had a case fatality rate among unvaccinated individuals that was at least 40% less than the so-called Alpha variant. This is a typical pattern of virus mutation: the virus becomes less dangerous because it wants to survive, and it can only survive in the long run by NOT killing its hosts! The decline in lethality is roughly demonstrated by Kelly Brown with data on in-hospital fatality rates from Toronto, Canada:

The case numbers in the U.S. have been climbing over the past few weeks, but as epidemiologist Larry Brilliant of WHO said recently, Delta spreads so fast it essentially “runs out of candidates.” In other words, the current surge is likely to end quickly. This article in Issues & Insights shows the more benign nature of recent infections. I think a few of their charts contain biases, but the one below on all-cause mortality by age group is convincing:

The next chart from Our World In Data shows the infection fatality rate continuing its decline in the U.S. The great majority of recent infections have been of the Delta variant, which also was much less virulent in the UK than earlier variants.

Furthermore, it turns out that the vaccines are roughly as effective against Delta and other new variants as against earlier strains. And the newest “scary” variants, Kappa and Lambda, do not appear to be making strong inroads in the U.S. 

Fading Efficacy?

There have been questions about whether the effectiveness of the vaccines is waning, which is behind much of the hand-wringing about booster shots. For example, Israeli health officials are insisting that the effectiveness of vaccines is “fading”, though I’ll be surprised if there isn’t some sort of confounding influence on the data they’ve cited, such as age and co-morbidities. 

Here is a new Mayo Clinic study of so-called “breakthrough” cases in the vaccinated population in Minnesota. It essentially shows that the rate of case diagnosis among the vaccinated rose between February and July of this year (first table below, courtesy of Phil Kerpen). However, the vaccines appear only marginally less effective against hospitalization than in March (second table below).

The bulk of the vaccinated population in the U.S. received their jabs three to six months ago, and according to this report, evidence of antibodies remains strong after seven months. In addition, T-cell immunity may continue for years, as it does for those having acquired immunity from an earlier infection. 

Breakthroughs

It’s common to hear misleading reports of high numbers of “breakthrough” cases. Not only will these cases be less menacing, but the reports often exaggerate their prevalence by taking the numbers out of context. Relative to the size of the vaccinated population, breakthrough cases are about where we’d expect based on the original estimates of vaccine efficacy. This report on Massachusetts breakthrough hospitalizations and deaths confirms that the most vulnerable among the vaxed population are the same as those most vulnerable in the unvaxed population: elderly individuals with comorbidities. But even that subset is at lower risk post-vaccination. It just so happens that the elderly are more likely to have been vaccinated in the first place, which implies that the vaccinated should be over-represented in the case population.

Conclusion

The COVID-19 vaccines do what they are supposed to do: reduce the dangers associated with infection. The vaccines remain very effective in reducing the severity of infection. However, they cannot and were not engineered to prevent infection. They also pose risks, but individuals should be able to rationally assess the tradeoffs without coercion. Poor messaging from public health authorities and the crazy distortions promoted in some circles does nothing to promote public health. Furthermore, there is every reason to believe that the current case surge in Delta infections will be short-lived and have less deadly consequences than earlier variants.