Recovering From COVID-19 Doesn’t Guarantee Antibodies or Confer Immunity to Re-Infection

Biological Anthropologist Thom McDade

Thomas McDade in his Northwestern University lab testing for SARS-CoV-2 (the virus that causes COVID-19) antibodies. Credit: Northwestern University

COVID-19 Antibody Study Shows Downside of Not Receiving Second Shot

A new study shows that two months after the second Pfizer/Moderna vaccination, antibody response decreases 20% in adults with prior cases of COVID-19. The study also tests how well current vaccines resist emerging variants.

The Northwestern University study underscores the importance of receiving a second dose of vaccine, not only because it is commonly known that immunity from vaccines wanes over time, but also because of the risk posed by emerging variants, including the highly contagious delta variant.

The study also showed that prior exposure to SARS-CoV-2 does not guarantee a high level of antibodies, nor does it guarantee a robust antibody response to the first vaccine dose. This directly contradicts the assumption that contracting COVID will naturally make someone immune to re-infection. The findings further support vaccination (and two doses), even for people who have contracted the virus previously.

A team of scientists, including biological anthropologist Thomas McDade and pharmacologist Alexis Demonbreun, tested blood samples from adults who had tested positive for SARS-CoV-2 to measure how long the immunity benefits of Pfizer and Moderna vaccines last and how well they protect from newer variants.

Study participants were selected from a racially and ethnically diverse community-based sample of Chicago-area adults recruited at the start of the pandemic. Using at-home antibody testing kits developed in the lab, participants submitted blood samples two to three weeks after their first and second dose of vaccination and two months after the second dose.

Antibody response after second shot

In the lab, the researchers tested for neutralizing antibodies by measuring whether the blood sample could inhibit the interaction between the virus’ spike protein and the ACE2 receptor – this interaction is how the virus causes an infection once it enters the body.

“When we tested blood samples from participants collected about three weeks after their second vaccine dose, the average level of inhibition was 98%, indicating a very high level of neutralizing antibodies,” said McDade, professor of anthropology in the Weinberg College of Arts and Sciences and a faculty fellow with the University’s Institute for Policy Research.

The scientists tested emerging variants B.1.1351 (South Africa), B.1.1.7 (UK) and P.1 (Brazil) and found the level of inhibition to viral variants was significantly lower, ranging from 67% to 92%.

Antibody response declined after two months

In testing samples collected two months after the second dose, they found antibody responses declined by about 20%.

The researchers found that the antibody response to vaccination varied based on history of prior infection.

Individuals with clinically confirmed cases of COVID-19 and multiple symptoms had a higher level of response than those who tested positive but had mild symptoms or were asymptomatic.

“Many people, and many doctors, are assuming that any prior exposure to SARS-CoV-2 will confer immunity to re-infection. Based on this logic, some people with prior exposure don’t think they need to get vaccinated. Or if they do get vaccinated, they think that they only need the first dose of the two-dose Pfizer/Moderna vaccines,” McDade said.

“Our study shows that prior exposure to SARS-CoV-2 does not guarantee a high level of antibodies, nor does it guarantee a robust antibody response to the first vaccine dose. For people who had mild or asymptomatic infections, their antibody response to vaccination is essentially the same as it is for people who have not been previously exposed.” 

McDade adds that although the research was conducted prior to the emergence of the delta virus, the conclusions are similar.  

“As far as protection goes after vaccination, the story is the same for all the variants, including delta — the vaccine provides good protection, but not as good protection as the original version of the virus for which the vaccine was designed. Combine that with the fact that immunity wanes over time, you get increased vulnerability to breakthrough infection. 

“So, it’s two strikes right now — delta plus waning immunity among the first wave of the vaccinated,” McDade said.

Reference: “Durability of antibody response to vaccination and surrogate neutralization of emerging variants based on SARS-CoV-2 exposure history” by Thomas W. McDade, Alexis R. Demonbreun, Amelia Sancilio, Brian Mustanski, Richard T. D’Aquila and Elizabeth M. McNally, 30 August 2021, Scientific Reports.
DOI: 10.1038/s41598-021-96879-3

28 Comments on "Recovering From COVID-19 Doesn’t Guarantee Antibodies or Confer Immunity to Re-Infection"

  1. oh no! Rand Paul’s School of Immunology fails again.

  2. more fake news propaganda to enforce the jab. scientifically speaking screwing with our immune system and attempting to re-engineer it frivolously is both dangerous and stupid.

  3. Unfortunately, this headline is false. If you read the actual research article it indicates, “In an IRB-approved community-based serological study, we compared vaccine response in 27 study participants (mean age 39.7 years, 51.9% female, 59.3% Pfizer, 40.7% Moderna). Research is fine – headline is not. If Editor is really interested in natural immunity they should look at the “Comparing SARS-CoV-2 natural immunity to vaccine-induced immunity: reinfections versus breakthrough infections” study which looked at tens of thousands of records.

  4. An immune response is so much more than antibodies.

  5. The “study” was done “at the start of the pandemic” and had to do with counting antibodies. Anyone talking about antibody counts and immunity is feeding you a load of nonsense, since antibodies are a transitory part of the body’s fight against a virus and are discarded once the virus is defeated. They are not part of the body’s immune system, per se, they are a tool that the immune system creates as needed to fight the virus when the virus is present.

  6. Lmfao fake headline this is talking about the first jab v second jab cause the Israeli study proves immune system is far superior to jab

    • funny since Israel is stepping up their boosters

      • The two are not mutually exclusive. You can know natural immunity is superior but still use a vaccine. Boosters are for those already vaccinated, not those with a natural immunity.

  7. Still learning | August 30, 2021 at 7:53 am | Reply

    My friend has been infected twice. I did the math with her. 110 days apart. Very weird. The median time frame for those reinfected is 110. Not so weird when you think about what median is by definition. My friend sent me a video of what the vaccine does purportedly. I did not have the heart to tell my friend what the virus does to your heart,lungs or vascular. Lately I have come to believe that the best physical outcome is no vaccine with no infection. Next best outcome is a breakthrough infection with the vaccine. And the least desirable is an infection without the vaccine. The three outcomes do not take into account the moral obligation to not be a vector in another human’s passing or probably worse the diminishing of the quality of their life by persistent symptoms. Researchers say the vaccines have a limited time frame of disruptive behavior to our bodies. Sort of like a firework called a sparkler. You hold it and it burns out before it gets close to burning the hand holding it. By design the vaccines only have so much material that can be processed. The vaccines are administered in the arm and create a reaction locally there and the closest component of our lymphatic system. Probably the lymph nodes underneath the arm pit. In contrast breathing in an overdose of virus particles is not going to be a good outcome. The size of that sparkler is really big and going to burn a really long time and do a lot of damage before it burns out. Life is full of choices. Sometimes we pick the thing which is going to result in the least damage when damage is inevitable. Damage to our self and damage to the common good. There is certainly a risk involved here. There are unknowns. One must look deep into their own heart and contemplate the issues.I love you. Yes you reading this.

  8. Many huge studies contradict this study including 20,000 people in Israel!

  9. This is a misleading article. Persons who are asymptomatic but test positive dont have the natural immunity because they are mostly false positives. I agree with the above post that says this is just propaganda to convince people to get the jab. Natural immunity is far superior to the vax. I’m not anti-vax by any means, but why bend the stats with lies?

    • Great point! Testing positive could be false positive, especially if the positive people the article is discussed are from a year ago.

  10. I agree with Spike. The engineers of the covid 19 virus also engineered the vaccine. Welcome to the New World Order. George Bush would be proud. Let’s get that global population down to less than 500,000,000!Then we can enjoy OUR planet without all these serfs taking up space and competing with our resources. Their numbers are simply not sustainable at current levels.

  11. Spike is not speaking scientifically. Spike should move to Montana with the rest of the anti vaccine crowd.

  12. Fake news. Here is the real deal with natural immunity.

    • That’s really helpful! It explains a lot, too. I’ve been looking for a study or something like this! The way the immune system is being talked about makes no sense, and this explains it a bit. Thank you!

  13. Going with Manufacturer parts obtained thru infection.
    No after market vaccine to throw everything out of balance.
    Man is so smart though, oh they will get back to you on the cure for the common cold I believe is part of the corona virus family.

  14. More of their bull crap trying to push their vaccine and make their big bucks in the process give you all kinds of heart problems blood problems cancer anything that these vaccines want to mess with your body. It’s all about scare tactics. I already know a lot of people that took the vaccine early on got the first virus the covid-19 and now they’ve got the other virus also so that’s how we’re well these vaccines work. One thing we are not guinea pigs we are humans.

  15. Um I wish people would stop calling it a study when the sampling size is so minuscule that I can do better observational studies of my neighbors and friends. While I appreciate the attempt this is just not a big enough study to produce sound advice. We always knew that natural infection may or may not result in immunity therefore it is risky to only get 1 jab. In fact testing IS the BEST way to prevent the spread of COVID but the government has really lost its mind (and lets be real no one trust WHO or the CDC) thinking the world should TRUST hypothesis when we all know the research is NOT THERE YET is what is causing distrust! This mess with Biden is sending even more signals that people do NOT trust the government when they blatantly lie to us. The truth is no one knows and also to this person who is “Still Learning” you are a viral vector with or without vaccination. Haven’t you heard vaccinated people can infect others? That is the whole ignored point of all of this, getting vaccinated doesn’t stop the spread and doesn’t stop the mutation of the virus. Therefore vaccination is about personal protection, and PERSONAL CHOICE. It is NOT about stopping COVID its not going anywhere anytime soon unless we start testing more. That is how you address this virus and by all means yes recommemd vaccinating high risk population’s (30 or 40+ and people with health problems, pregnant women) but you can’t force people. If we get to the point where our US healthcare system cannot manage their patients hosptials have a choice to deny care to high risk/elderly populations who refused vaccination. Let that be their problem and their choice. Shame on Fauci for recommending mandates for young people who are at very little risk, .00001 of positive tested patients (not including people who didn’t get tested or were asymoptomatic 50 to 80%) which makea the risk of death in young people 1 in 500,000 to 1 in a million is NOT a reason to mandate vaccine in young people.I once stood by Fauci now I think under this administration him and his people have turned into tyrants. Do you all remmeber not long ago it wqs promised they wouldn’t force vaccine mandates, now they changed their mind? People are going to avoid vaccination so long as it’s mandated. People are willing to die for their individual freedoms. If you force people to vaccinate they are going to perceive it as a war on their individual freedoms and rights and they will avoid vaccination because you are impending on their human rights (defined by UNESCO themselves). The reality is it IS against their basic human rights forget the constitution this is bigger than the constituition. Unless vaccines STOP COVID the mandates and push to vaccinate those who are at little to no risk needs to stop!

  16. Neither does the vaccine. So many of my friends who have had the vaccine are either now or were infected.

  17. Adaptive immunity is strong and protective… If you are a spike protein manufacturer and part of your innate immune system has been turned off… Then you will get sick.

  18. I don’t see how this information proves a loss of immunity over time. (Which means a loss of the body’s memory of the pathogen, which normally would stick around.)

    Antibodies in the body will wane over time. That’s normal, and the testing of antibodies in people two months out from illness shows a reduction, according to this article. This doesn’t prove the body has reduced immunity. It only proves the body has fewer antibodies. Later, if the body is infected by covid, the body should recognize and remember it, then respond quickly to it, just like with other viruses.

  19. No unvaccinated control

  20. We are fearfully and Wonderfully made .Yes you will have the deceivers to tell u a lie.How can a synthetic jab be better than your natural immunity?Don’t let them fool you.

  21. These People who are calling the Scientific Study “Fake News”, why are they reading the Science Daily… Go to Fox so called news website

  22. This is so obviously a grotesque interpretation and purposeful muddying of science to persuade people unethically. Immediate virus fighting antibodies naturally wane after any virus you have contracted, or vaccine you’ve taken. It’s about antibodies and the b and t cells that you produce which create antibodies that allows long term strong immunity. Not to mention natural immunity creates memory cells for every protein in the virus:nucleo, envelope, spike, and membrane. Vaccine causes your body to create only spike protein antibodies and memory cells. Recently a report from Cell medical journal showed that natural immunity actually boosts immune response even for sars-1 as well as variants of sars-2.
    Quit spreading misinformation. You’re just as bad as the far right misinformation.

Leave a comment

Email address is optional. If provided, your email will not be published or shared.