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| Science & Technology |
| Protection and waning of natural and hybrid COVID-19 immunity |
| 2021-12-13 |
| Authors: Yair Goldberg, Micha Mandel, Yinon M. Bar-On, Omri Bodenheimer, Laurence Freedman, Nachman Ash, Sharon Alroy-Preis, Amit Huppert, Ron Milo Abstract: [MEDRXIV] BACKGROUND Infection with SARS-CoV-2 provides substantial natural immunity against reinfection. Recent studies have shown strong waning of the immunity provided by the BNT162b2 vaccine. The time course of natural and hybrid immunity is unknown. METHODS Data on confirmed SARS-CoV-2 infections were extracted from the Israeli Ministry of Health database for the period August to September 2021 regarding all persons previously infected or vaccinated. We compared infection rates as a function of time since the last immunity-conferring event using Poisson regression, adjusting for possible confounding factors. RESULTS Confirmed infection rates increased according to time elapsed since the last immunity-conferring event in all cohorts. For unvaccinated previously infected individuals they increased from 10.5 per 100,000 risk-days for those previously infected 4-6 months ago to 30.2 for those previously infected over a year ago. For individuals receiving a single dose following prior infection they increased from 3.7 per 100,000 person days among those vaccinated in the past two months to 11.6 for those vaccinated over 6 months ago. For vaccinated previously uninfected individuals the rate per 100,000 person days increased from 21.1 for persons vaccinated within the first two months to 88.9 for those vaccinated more than 6 months ago. CONCLUSIONS Protection from reinfection decreases with time since previous infection, but is, nevertheless, higher than that conferred by vaccination with two doses at a similar time since the last immunity-conferring event. A single vaccine dose after infection helps to restore protection. |
| Posted by:Thing From Snowy Mountain |
| #11 Beautifully said, Chealing Chomotle4158. |
| Posted by: trailing wife 2021-12-13 23:49 |
| #10 Key phrase: died WITH, not FROM. Why was the person hospitalized to begin with? What age? What comorbid conditions? What was the proximate cause of death? Boris Johnson statement was disingenuous and misleading! Deliberately ambiguous phrasing, demand the whole truth. |
| Posted by: Greater the Anonymous5721 2021-12-13 23:36 |
| #9 Boris Johnson in the UK today stated one patient there has died with or of the Omicron variant. That is the first death published for the variant. Nothing yet heard from South Africa or the rest of Europe. |
| Posted by: Bubba Lover of the Faeries8843 2021-12-13 22:53 |
| #8 Hospitalization rates bottomed out in mid-summer, peaked around Labor Day, and fell non-stop until about Thanksgiving, when they started trending up again. Today, there are 15,001 "Serious/Critical" per Worldometers, about the same as mid-October. But we are well into what used to be "The Flu Season", but flu deaths have been practically zero since the end of the flu season (April) 2020. That's twenty months without a flu season. Draw your own conclusions - those are (some of) the facts! |
| Posted by: Bobby 2021-12-13 18:34 |
| #7 Hysterical Covidianism is the virulence |
| Posted by: Merrick Ferret 2021-12-13 18:28 |
| #6 At this point in time, infection is not the important thing, SEVERITY is. Are the natural, acquired, and hybrid immunity groups showing any differential in severity and hospitalization and fatality compared to each other and to the baseline? If the Omicron variety and the symptoms are no more than a mild cold and resulting in far fewer hospitalizations, as it is so far, then the infection rate does not matter - in fact, you want it higher, to out-compete the more severe version and eradicate it, whilst providing some degree of immunity, and achieving "herd immunity". Infection rates are a crap statistic when isolated from the full context. Evolution is Random, But Guaranteed. Most mutations are dead ends and produce non-viable results. But if it replicates and mutates quickly enough, the random nature means it will eventually hit on a viable mutation. Viruses are primed to evolve very rapidly. They reproduce rapidly many times in a host, leading quickly to many generations of viruses. In the case of Covid, it is a single strand, so it doesn't have any error checking or correction systems for repairing RNA/DNA damage, so mutations stick around and aren’t corrected. This is why we need a new flu shot every year, why it’s not worth the effort to create a vaccine for the “common cold” (which could be caused by any one of a number of different strains of virus). And thats why we are seeing many variants of COVID So now it comes down to 2 factors: transmissibility and virulence. Increased transmissibility is a favorable mutation, in that it allows the virus to spread to more hosts, and outcompete other variants, and evade any immunity developed to other forms. Higher transmissible viruses will become more common due to "competition of the fittest". So increased transmissibility is inevitable. As for virulence? It is rather simple. Killing the host too fast or making them too sick to interact with others may prevent the virus from getting a chance to spread. This is why virulent forms like Ebola tend to "burn themselves out" before they can evolve to a milder form, and use an animal population for their "reservoir". So virulence is not an advantage when competing with other forms of the virus, especially since the asymptomatic or mildly symptomatic will carry it and not be likely to treat it. There is evidence that the coronavirus that causes most of the “common cold” today came from a virus called OC43, which might have been responsible for an 1890 pandemic that killed over a million people. That virus grew less virulent over time, becoming little more than a nuisance. So "waiting it out" can be a valid strategy, although the death and damage while waiting for a less virulent form to dominate mark it as an unsustainable strategy, as well as an inhumane one. Omicron is a natural development that most viruses tend toward - more contagious but milder symptoms and less virulent. Like the flu and the common cold (also a coronavirus). This is a mutant that we can take advantage of. The panic over Omicron is not only stupid, but it is also counterproductive if, in fact, Omicron is a very much less virulent form. All the countries instituting severe measures like extreme lockdowns (Israel, Australia) are doing their populations far more harm than good. The same goes for mandates for the mRNA for children who have a minuscule risk for fatality or hospitalization absent other comorbid factors. So context - how is this affecting HOSPITALIZATION rates? Infection rates are meaningless without that context. Transmissibility is only half the equation. Whats the virulence? |
| Posted by: Chealing Chomotle4158 2021-12-13 16:33 |
| #5 Uh, no. It's about immunity. I posted the abstract; you can also read the whole paper if you click the link. Unless I screwed that up too. |
| Posted by: Thing From Snowy Mountain 2021-12-13 16:01 |
| #4 Is this the same Israeli study that concluded masks were useless but they decided to require them anyway? |
| Posted by: Vespasian Ebboting9735 2021-12-13 14:42 |
| #3 Well, thanks, again. |
| Posted by: Thing From Snowy Mountain 2021-12-13 14:07 |
| #2 Page 3 is right, Snowy Thing. WoT is the default setting for article submission — you hit Submit a moment too soon. |
| Posted by: trailing wife 2021-12-13 13:15 |
| #1 I think I meant to put this on page 3. I probably shouldn't have been doing two things at once. Anyway, that previous Israeli study on vaccine and natural immunity now has a followup, here it is. |
| Posted by: Thing From Snowy Mountain 2021-12-13 13:06 |