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Long covid after breakthrough infection

Discussion in 'Long Covid news' started by Wyva, Jul 28, 2021.

  1. Wyva

    Wyva Senior Member (Voting Rights)

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    Preprint: Breakthrough Symptomatic COVID-19 Infections Leading to Long Covid: Report from Long Covid Facebook Group Poll, 2021, Massey et al

    Abstract

    Vaccines have been shown to be extremely effective in preventing COVID-19 hospitalizations and deaths. However, a question remains whether vaccine breakthrough cases can still lead to Post-Acute Sequelae of SARS-CoV-2 (PASC), also known as Long Covid. To address this question, the Survivor Corps group, a grassroots COVID-19 organization focused on patient support and research, posted a poll to its 169,900 members that asked about breakthrough cases, Long Covid, and hospitalizations.

    1,949 people who self-report being fully vaccinated have responded to date. While robust data are needed in a larger, unbiased sample to extrapolate rates to the population, we analyzed the results of this public poll to determine what people were reporting regarding Long Covid after breakthrough infection and to prompt discussion of how breakthrough cases are measured.

    The poll was posted in the Survivor Corps Facebook group (~169,900 members). Of the 1,949 participants who responded to the poll, 44 reported a symptomatic breakthrough case and 24 of those reported that the case led to symptoms of Long Covid. 1 of these 24 cases was reported to have led to hospitalization in addition to Long Covid.

    Open access (in PDF): https://www.medrxiv.org/content/10.1101/2021.07.23.21261030v1
     
    Last edited by a moderator: Oct 3, 2021
  2. ME/CFS Skeptic

    ME/CFS Skeptic Senior Member (Voting Rights)

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    Merged thread

    Covid-19 Breakthrough Infections in Vaccinated Health Care Workers


    Abstract


    BACKGROUND
    Despite the high efficacy of the BNT162b2 messenger RNA vaccine against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), rare breakthrough infections have been reported, including infections among health care workers. Data are needed to characterize these infections and define correlates of breakthrough and infectivity.

    METHODS
    At the largest medical center in Israel, we identified breakthrough infections by performing extensive evaluations of health care workers who were symptomatic (including mild symptoms) or had known infection exposure. These evaluations included epidemiologic investigations, repeat reverse-transcriptase–polymerase-chain-reaction (RT-PCR) assays, antigen-detecting rapid diagnostic testing (Ag-RDT), serologic assays, and genomic sequencing. Correlates of breakthrough infection were assessed in a case–control analysis. We matched patients with breakthrough infection who had antibody titers obtained within a week before SARS-CoV-2 detection (peri-infection period) with four to five uninfected controls and used generalized estimating equations to predict the geometric mean titers among cases and controls and the ratio between the titers in the two groups. We also assessed the correlation between neutralizing antibody titers and N gene cycle threshold (Ct) values with respect to infectivity.

    RESULTS
    Among 1497 fully vaccinated health care workers for whom RT-PCR data were available, 39 SARS-CoV-2 breakthrough infections were documented. Neutralizing antibody titers in case patients during the peri-infection period were lower than those in matched uninfected controls (case-to-control ratio, 0.361; 95% confidence interval, 0.165 to 0.787). Higher peri-infection neutralizing antibody titers were associated with lower infectivity (higher Ct values). Most breakthrough cases were mild or asymptomatic, although 19% had persistent symptoms (>6 weeks). The B.1.1.7 (alpha) variant was found in 85% of samples tested. A total of 74% of case patients had a high viral load (Ct value, <30) at some point during their infection; however, of these patients, only 17 (59%) had a positive result on concurrent Ag-RDT. No secondary infections were documented.

    CONCLUSIONS
    Among fully vaccinated health care workers, the occurrence of breakthrough infections with SARS-CoV-2 was correlated with neutralizing antibody titers during the peri-infection period. Most breakthrough infections were mild or asymptomatic, although persistent symptoms did occur.

    Full text: https://www.nejm.org/doi/full/10.1056/NEJMoa2109072
     
    Last edited by a moderator: Nov 15, 2021
  3. ME/CFS Skeptic

    ME/CFS Skeptic Senior Member (Voting Rights)

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    An Israelian study in New England suggesting that some people who are vaccinated may still go on to have persistent symptoms after 6 weeks. The sample size was relatively small. Vaccines protect people really well from severe infection, but I really hope they will be equally effective at preventing long covid.
     
  4. ME/CFS Skeptic

    ME/CFS Skeptic Senior Member (Voting Rights)

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  5. perchance dreamer

    perchance dreamer Senior Member (Voting Rights)

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    My husband and I had a trip to Orlando next week to visit family. We're both vaccinated and always wear masks inside, so I figured it would be okay.

    But I found out yesterday that it's even worse in Orlando than we thought. The city is in a state of emergency with covid cases, and hospitals are putting cots outside to deal with the overflow. I keep reading about breakthrough cases that can happen with the fully vaccinated, especially now with the more contagious Delta variant. I decided to cancel the trip because I don't feel comfortable with both DH and me going to Orlando under these conditions. It's so disappointing and frustrating.
     
  6. rvallee

    rvallee Senior Member (Voting Rights)

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    So the risk of infection is massively reduced, about 2.6% in this sample, while the risk of LC hovers at about 1%, which is consistent with the recent Survivor Corps study. And just as the Body Politic study showed, clearly it has stood the test of time, as long as it's well-done there is no specific reason why a formal study by health care professionals is significantly better than a patient-led community study, as long as it remains based on questionnaires. This isn't exactly rocket surgery here, let's be frank.

    Roughly about half of long haulers at 6 weeks appear to be significantly impaired, so a real absolute long-term risk of about 0.5%. Which mixed with herd immunity would still be quite disastrous as it would largely affect the youngish adult working age population, especially putting some professions like medical professionals and teachers at increased risk.

    And of course that doesn't consider the possibility of a later variant having worst odds. Still the problem here could be that the numbers are just low enough to not care. It's been found that it takes about 3% of a population to force social and political change. That's too low, still possible to bury if those numbers hold up.

    The risk for most insurance-covered disasters, whether accidents, house fires, flooding, are significantly lower than this and the average person spends hundreds per year on those.
     
  7. Graham

    Graham Senior Member (Voting Rights)

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    Interesting. My wife took 3 weeks to recover from her first AZ jab.
     
  8. Leila

    Leila Senior Member (Voting Rights)

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    Do the vaccines contribute to the mutation of new variants like Delta?

    If we didn't have the vaccines, would we still only have Alpha? Or do these mutations happen anyway?

    I'm wondering if without the vaccines we'd have a lot more severely affected and a high death rate but with the vaccine a lot more LC cases due to more transmissable variants.

    The breakthrough infections do worry me.

    Seems like community transmissions need to be kept low until everybody is vaccinated.

    But restrictions are being lifted everywhere and so the virus can happily pingpong between the vaccinated and unvaccinated.
     
    Last edited: Jul 30, 2021
  9. Snow Leopard

    Snow Leopard Senior Member (Voting Rights)

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    Mutations are a stochastic process, so more vaccinations means less mutations due to reduction in cases!

    Vaccines can apply 'selection pressures' that can lead to vaccine escape mutations, but the virus seems to be becoming more virulent just fine without the help of vaccines.
     
    Hutan, alktipping, Louie41 and 9 others like this.
  10. Leila

    Leila Senior Member (Voting Rights)

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    Thanks for the clarification! That's reassuring. Do you think booster jabs will be necessary later?
     
  11. Snow Leopard

    Snow Leopard Senior Member (Voting Rights)

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    I think vaccinations against variants will be necessary in the future. It might not be annually, but biennially (every two years).
     
    alktipping, Louie41, FMMM1 and 5 others like this.
  12. Peter Trewhitt

    Peter Trewhitt Senior Member (Voting Rights)

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    Boosters may be needed for two reasons, one to boost the effect of the initial vaccination which wears off over time, and the other to modify the the resultant immunity to include new variants.

    The length of time the vaccine induced immunity lasts varies between different vaccines/viruses, from a life time to a matter of months. Obviously we are only still learning about how long the Covid 19 vaccine induced immunity will last, but current signs are that it declines relatively rapidly meaning annual or biannual boosters are likely be needed to maintain the initial effect.

    As a virus mutates the the immunity conferred by a vaccine may no longer work with new variants. The seasonal Influenza virus mutates fairly rapidly and we have no vaccine that covers the full range of current forms, so with the annual flue jabs an educated guess is made as to which is likely to be the most common variant this season and people are vaccinated against that form, meaning they have little or no vaccine induced immunity for other forms of the virus. So far the new variants of Covid 19 are not so different that they totally escape current vaccine induced immunity, so it is likely that tweaked booster shots will in the immediate future be up to meeting the challenge of new variants. We have no idea if Covid 19 will mutate such that in the future we would need different vaccines against different strains.
     
  13. Leila

    Leila Senior Member (Voting Rights)

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    Appearently Israel is already promoting a third jab for people >60. That's only a couple of months after that population has had their 2nd jab...

    "Thursday's announcement follows a strong recommendation from the government-appointed team of experts on the pandemic to offer older adults a third dose.

    The experts' advice, which came overnight on Wednesday, was based on data suggesting significant waning immunity from infection over time."
     
    alktipping, Louie41, Helene and 4 others like this.
  14. Mij

    Mij Senior Member (Voting Rights)

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    The CDC report said Delta is highly contagious, likely more severe than other variants and breakthrough infections may be as transmissible as unvaccinated cases. The Delta variant spreads like Chicken Pox, so instead of one infection infecting 3, it infects 8 people.
     
  15. Snow Leopard

    Snow Leopard Senior Member (Voting Rights)

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    I hope that isn't true!

    Most of the models governments have been using have been based on (this is a random transmission model which works on the large scale, but not so accurate on the small scale):

    R effective = Rz (reduction in transmission of breakthrough cases * proportion vaccinated + proportion unvaccinated)*(proportion vaccinated (1-Vaccine efficacy against symptoms) + proportion unvaccinated)

    Rz is the effective R for various social restrictions other than vaccination - if there are no restrictions, then Rz=R0, which is often quoted to be 5 for delta)

    The goal is R effective < 1 means the outbreak will be self-limited.

    This sort of model also assumes that transmission from true asymptomatic cases is very rare, which is empirically justified.

    Many models have been assuming a 40-50% reduction in transmissibility of breakthrough cases.

    If there is no reduction in transmission of breakthrough cases, then the only way to obtain R eff<1 is with long-term restrictions (masks, lockdowns) or by vaccinating over 90% of the total population with a 90% effective vaccine. 85% is not good enough - AZ is not good enough even with 100% vaccinated. I'm not sure if boosters would even help enough, unless vaccination rates are very high (95%).
     
    alktipping, Louie41, FMMM1 and 4 others like this.
  16. Wyva

    Wyva Senior Member (Voting Rights)

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    Hungary too: you can already apply for your third vaccine four months after your second jab. Anyone, not just old people, but people in risk groups are probably prioritized again. However, now your vaccine has to be a different type from your previous ones (so no mRNA for the third time, etc), unless there are medical reasons against a different type.

    However, here this probably happened because of the Sinopharm controversy: a lot of people, especially over 60 had negative antibody test results after that vaccine. So this is probably mostly to calm those people down and to get rid of all those remaining Sinopharm vaccines at the same time. (Not sure the latter will work now.)
     
  17. Mij

    Mij Senior Member (Voting Rights)

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    @Snow Leopard

    It cites a combination of recently obtained, still unpublished data from outbreak investigations and outside studies showing that vaccinated individuals infected with delta may be able to transmit the virus as easily as those who are unvaccinated. Vaccinated people infected with delta have measurable viral loads similar to those who are unvaccinated and infected with the variant.
     
  18. Snow Leopard

    Snow Leopard Senior Member (Voting Rights)

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    Viral loads at the start of an infection is not a sufficient proxy for transmissibility, given that those viral loads may diminish much faster since the immune system has already been primed, and hence be infectious for a shorter period of time. Only a community based (whole population) contact tracing study with sufficient sample size can reasonably compare transmissibility.
     
    alktipping, Helene, FMMM1 and 4 others like this.
  19. Mij

    Mij Senior Member (Voting Rights)

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    @Snow Leopard

    What they're saying now is that infections with Delta lead to higher viral loads and persist for longer than was seen with previous strains, meaning an infected person is likely contagious for longer.

    Virus levels can be as high in breakthrough cases as in unvaccinated people, even if vaccinated people don’t get nearly as sick.
     
  20. rvallee

    rvallee Senior Member (Voting Rights)

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    Accounting for the fact that breakthrough infections are less likely to occur after immunization and are less severe, the risk of Long Covid appears relatively the same. Which could tell us something about the process that kickstarts it.

    https://twitter.com/user/status/1453299718432374784


    Six-month sequelae of post-vaccination SARS-CoV-2 infection: a retrospective cohort study of 10,024 breakthrough infections
    https://www.medrxiv.org/content/10.1101/2021.10.26.21265508v1

    Receiving at least one COVID-19 vaccine dose was associated with a significantly lower risk of respiratory failure, ICU admission, intubation/ventilation, hypoxaemia, oxygen requirement, hypercoagulopathy/venous thromboembolism, seizures, psychotic disorder, and hair loss (each as composite endpoints with death to account for competing risks; HR 0.70-0.83, Bonferroni-corrected p<.05), but not other outcomes, including long-COVID features, renal disease, mood, anxiety, and sleep disorders.

     
    Last edited by a moderator: Nov 15, 2021

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