Natural Immunity lasts longer than BioNTech vaccination immunity of less than 5 months

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nerd

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This has been asked in other posts because users were uncertain whether and when to get vaccinated after a natural infection. The newest data from Israel shows good and long protection from natural immunity, and also when the third shot will be necessary for the BioNTech vaccine, i.e. after 4-5 months.

Preprint: Elapsed time since BNT162b2 vaccine and risk of SARS-CoV-2 infection in a large cohort
Ariel Israel, Eugene Merzon, Alejandro A. Schäffer, Yotam Shenhar, Ilan Green, Avivit Golan-Cohen, Eytan Ruppin, Eli Magen, Shlomo Vinker

medRxiv 2021.08.03.21261496; doi: 10.1101/2021.08.03.21261496
Importance Israel was among the first countries to launch a large-scale COVID-19 vaccination campaign, and quickly vaccinated its population, achieving early control over the spread of the virus. However, the number of COVID-19 cases is now rapidly increasing, which may indicate that vaccine protection decreases over time.
Objective To determine whether time elapsed since the second BNT162b2 messenger RNA (mRNA) vaccine (Pfizer-BioNTech) injection is significantly associated with the risk of post-vaccination COVID-19 infection.
Design This is a retrospective cohort study performed in a large state-mandated health care organization in Israel.
Participants All fully vaccinated adults who have received a RT-PCR test between May 15, 2021 and July 26, 2021, at least two weeks after their second vaccine injection were included. Patients with a history of past COVID-19 infection were excluded.
Main Outcome and Measure Positive result for the RT-PCR test.
Results The cohort included 33,993 fully vaccinated adults, 49% women, with a mean age of 47 years (SD, 17 years), who received an RT-PCR test for SARS-CoV-2 during the study period. The median time between the second dose of the vaccine and the RT-PCR test was 146 days, interquartile range [121-167] days. 608 (1.8%) patients had positive test results. There was a significantly higher rate of positive results among patients who received their second vaccine dose at least 146 days before the RT-PCR test compared to patients who have received their vaccine less than 146 days before: odds ratio for infection was 3.00 for patients aged over 60 (95% CI 1.86-5.11); 2.29 for patients aged between 40 and 59 (95% CI 1.67-3.17); and 1.74 for patients aged between 18 and 39 (95% CI 1.27-2.37); P<0.001 in each age group.
Conclusions and Relevance In this large population study of patients tested for SARS-CoV-2 by RT-PCR following two doses of mRNA BNT162b2 vaccine, we observe a significant increase of the risk of infection in individuals who received their last vaccine dose since at least 146 days ago, particularly among patients older than 60.

Preprint: Large-scale study of antibody titer decay following BNT162b2 mRNA vaccine or SARS-CoV-2 infection
Ariel Israel, Yotam Shenhar, Ilan Green, Eugene Merzon, Avivit Golan-Cohen, Alejandro A Schäffer, Eytan Ruppin, Shlomo Vinker, Eli Magen

medRxiv 2021.08.19.21262111; doi: 10.1101/2021.08.19.21262111
Background Immune protection following either vaccination or infection with SARS-CoV-2 decreases over time.
Objective To determine the kinetics of SARS-CoV-2 IgG antibodies following administration of two doses of BNT162b2 vaccine, or SARS-CoV-2 infection in unvaccinated individuals.
Methods Antibody titers were measured between January 31, 2021, and July 31, 2021 in two mutually exclusive groups: i) vaccinated individuals who received two doses of BNT162b2 vaccine and had no history of previous infection with COVID-19 and ii) SARS-CoV-2 convalescents who had not received the vaccine.
Results A total of 2,653 individuals fully vaccinated by two doses of vaccine during the study period and 4,361 convalescent patients were included. Higher SARS-CoV-2 IgG antibody titers were observed in vaccinated individuals (median 1581 AU/mL IQR [533.8-5644.6]) after the second vaccination, than in convalescent individuals (median 355.3 AU/mL IQR [141.2-998.7]; p<0.001). In vaccinated subjects, antibody titers decreased by up to 40% each subsequent month while in convalescents they decreased by less than 5% per month. Six months after BNT162b2 vaccination 16.1% subjects had antibody levels below the seropositivity threshold of <50 AU/mL, while only 10.8% of convalescent patients were below <50 AU/mL threshold after 9 months from SARS-CoV-2 infection.
Conclusions This study demonstrates individuals who received the Pfizer-BioNTech mRNA vaccine have different kinetics of antibody levels compared to patients who had been infected with the SARS-CoV-2 virus, with higher initial levels but a much faster exponential decrease in the first group.
 

TiredBill

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Nothing in this suggests that so-called "natural immunity" lasts longer or is as protective as a vaccine.

It does appear that the Delta wave is making a third shot of vaccine at about the 5 month mark necessarily to give full protection against infection, but two doses is still highly effective at keeping people out of hospitals and/or dying of Covid.

A staggering number of the current Covid deaths (is it 99%?) are among the unvaccinated.

The only way to acquire so-called natural immunity is to contract Covid. Not an optimal path.

Getting Covid not only puts one at great risk, but one risks exposing others to an illness that is proving to cause ME/CFS like disease.

If my actions caused another to develop ME/CFS, when I had the opportunity to act and stop the chain by getting a safe and effective vaccine, I don't think I could live with myself.

Bill
 

hapl808

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I believe in Los Angeles during Delta, approximately 85% of deaths are in unvaccinated people according to a recent study. The 99% number thrown around is a bit hyperbolic and without any reliable data.

But the 85% deaths in unvaccinated patients is in a city where the large majority of at-risk people are vaccinated (verging on 90%), so this is showing the vaccines have a very high real world effectiveness in reducing deaths and hospitalizations. When 90% of at-risk people are vaccinated, it is normal to see an increase of deaths and hospitalizations in vaccinated people. A vaccinated 90 year old will still be at higher risk than an unvaccinated 20 year old.

The study I saw did not look at previously infected individuals I believe, so no data was available on that.

However, vaccination or previous infection may both be helpful, but they are very far from perfect and people should continue to take additional precautions either way.
 

TiredBill

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Vaccines may not be "perfect," but they are highly excellent (and especially so with a third dose).

In contrast, getting Covid to acquire some measure of natural immunity risks one's life and the lives of others.

Bill
 

hapl808

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Vaccines may not be "perfect," but they are highly excellent (and especially so with a third dose).
Which is what I was saying - vaccines are showing to be very high effectiveness in real world scenarios. They are not showing 99% protection against serious illness and death and 99% of people in hospitals are not unvaccinated, so people should not assume their risks go to zero for serious illness or death after vaccination.

Ideally people should be fully vaccinated (and possibly with a booster) AND continue to take the precautions to the degree they are able.

I don't see any disagreement here.
 

TiredBill

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Which is what I was saying - vaccines are showing to be very high effectiveness in real world scenarios. They are not showing 99% protection against serious illness and death and 99% of people in hospitals are not unvaccinated, so people should not assume their risks go to zero for serious illness or death after vaccination.

Ideally people should be fully vaccinated (and possibly with a booster) AND continue to take the precautions to the degree they are able.

I don't see any disagreement here.
No disagreement, especially on the the bolded portion that people who are vaccinated should not assume their risk is zero and therefore it is important to take other measures (like masking) to layer protections.

As you correctly pointed out, the most highly vulnerable populations are heavily vaccinated, and the vaccines are reducing their death rates in a spectacular fashion. Miraculously good, in fact.

Bill
 

nerd

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Nothing in this suggests that so-called "natural immunity" lasts longer or is as protective as a vaccine.
Please read carefully before making such conclusive statements. 40% decline vs. less than 5% decline in Abs. Moreover over 15% lost seropositivity after six months while ca. 10% naturally immune patients had lost it after 9 months. This suggests that naturally immune patients can contribute to the necessary herd immunity threshold for at least 9 months without vaccination.

In vaccinated subjects, antibody titers decreased by up to 40% each subsequent month while in convalescents they decreased by less than 5% per month. Six months after BNT162b2 vaccination 16.1% subjects had antibody levels below the seropositivity threshold of <50 AU/mL, while only 10.8% of convalescent patients were below <50 AU/mL threshold after 9 months from SARS-CoV-2 infection.

The only way to acquire so-called natural immunity is to contract Covid. Not an optimal path.
Of course not. Nobody suggests intentionally getting infected. But some patients still get infected and have the question of how long their immunity will last. Speaking of adaptive immunity only because protection against hospitalizations lasts much longer but isn't of any use for herd immunity.

but two doses is still highly effective at keeping people out of hospitals and/or dying of Covid.
If ME patients want to avoid a third shot, I completely respect that. But it's naive to think that we just have to keep the general population out of hospitals. We need herd immunity at all costs. Otherwise, SARS-CoV-2 is just a ticking bio weapon, waiting for a major mutation that involves ADE, possibly making all vaccination technologies useless as they are useless for other viruses. The general population should get boosters after 5 months if they had the BioNTech vaccine.

However, vaccination or previous infection may both be helpful, but they are very far from perfect and people should continue to take additional precautions either way.
Definitely. They might even combine multiple therapies. I'm going to continue Ivermectin even after my Novavax shots. And I also appreciate the mask mandate since it keeps other pathogens away as well. The last thing you want to achieve with vaccinations is to outweigh the social distancing efforts because it gives a false sense of safety. With the masks, at least the officials always repeated that it doesn't protect completely and that you still have to be careful. Unfortunately, I don't see the same narrative with vaccinations. Their new narrative is kind of "if you're vaccinated, you can have your old life back".
 
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