Throughout the COVID-19 pandemic, there has been much uncertainty about how long immunity lasts after an unvaccinated person is infected with SARS-CoV-2.
Now a team of scientists led by faculty at Yale School of Public Health and the University of North Carolina at Charlotte have an answer: Strong protection following natural infection is short-lived.
“Reinfection can reasonably happen in three months or less,” said Jeffrey Townsend, the Elihu Professor of Biostatistics at the Yale School of Public Health and the study’s lead author. “Therefore, those who have been naturally infected should get vaccinated. Previous infection alone can offer very little long-term protection against subsequent infections.”
The study, published in the journal The Lancet Microbe, is the first to determine the likelihood of reinfection following natural infection and without vaccination.
Townsend and his team analyzed known reinfection and immunological data from the close viral relatives of SARS-CoV-2 that cause “common colds,” along with immunological data from SARS-CoV-1 and Middle East Respiratory Syndrome. Leveraging evolutionary principles, the team was able to model the risk of COVID-19 reinfection over time.
Reinfections can, and have, happened even shortly after recovery, the researchers said. And they will become increasingly common as immunity wanes and new SARS-CoV-2 variants arise.
“We tend to think about immunity as being immune or not immune. Our study cautions that we instead should be more focused on the risk of reinfection through time,” said Alex Dornburg, assistant professor of bioinformatics and genomics at the University of North Carolina at Charlotte, who co-led the study. “As new variants arise, previous immune responses become less effective at combating the virus. Those who were naturally infected early in the pandemic are increasingly likely to become reinfected in the near future.”
The team’s data-driven model reveals striking similarities to the reinfection risks over time between SARS-CoV-2 and endemic coronaviruses.
“Just like common colds, from one year to the next you may get reinfected with the same virus,” Townsend said. “The difference is that, during its emergence in this pandemic, COVID-19 has proven to be much more deadly.”
A hallmark of the modern world is going to be the evolution of new threats to human health, Townsend added. Evolutionary biology — which provided the theoretical foundations for these analyses — is traditionally considered a historical discipline.
“However, our findings underscore its important role in informing decision-making, and provide a crucial steppingstone toward robust knowledge of our prospects of resistance to SARS-CoV-2 reinfection,” he said.
Reference: “The durability of immunity against reinfection by SARS-CoV-2: a comparative evolutionary study” by Prof Jeffrey P Townsend, PhD; Hayley B Hassler, MS; Zheng Wang, PhD; Sayaka Miura, PhD; Jaiveer Singh; Prof Sudhir Kumar, PhD; Prof Nancy H Ruddle, PhD; Prof Alison P Galvani, PhD and Alex Dornburg, PhD, 1 October 2021, The Lancet Microbe.
DOI: 10.1016/S2666-5247(21)00219-6
Co-authors include researchers from Temple University. Funding for the research was provided by the U.S. National Science Foundation.
6 Comments
MSM continues to push out misinformation that natural infection immunity doesn’t last longer than 6 months (says less in this article)
Its been 10 months since I was infected with Covid 19. Just got tested Friday October 1, 2021 and my antibody levels are still 67.2 U/ml
A “positive” antibody level is > 0.9 U/ml
My fully vaccinated colleague got infected with the delta variant in begin December 2021. End January 2022 same guy got infected with omicron and even managed to pass it on to me. Both times he had symptoms and got positive tests. Can someone explain this to me?
Moreover I got my first jab of pfizer. 1 month after first jab I had 4700u/ml antibodies, 4 months after the first jab I had only 360u/ml antibodies. That means that only 6 months after a vaccine I had no protection. If I am to add the 3 weeks of headache after the first jab, I truly believe that is a useless vaccine.
How much are you being paid by the pharmaceutical industry to lie? Funny how “spikes” of the Delta will come during normal Flu seasons for unvaccinated. Give me a break!
How do I unsubscibe? Complete garbage.
LOL… not going to pop a hemorrhoid over this one. The key WORD here is MODEL. Like the GERMAN term MODEL (RAYON) is like SILK. In your DREAMS… unless you’re talking about the “Silk” fibres found in CURRENCY. And there is certainly more that ENUF of that SILK, FLOATING around to buy an opinion… or twenty… 😵 Just the same, one should WATCH where/what one is breathing but even a MASK won’t spare one the SMELL. Like my personal physician advised: Stay TF out of hospitals, and away from VAC advocates and Politicians with an AGENDA. What they have might be CATCHING… 🤮 With or without your CONSENT.
These researchers are trying to understand future infections of Covid-19 by using a model from other coronaviruses, but there still doesn’t seem to be much interest in the virus itself, not its protein spikes.
All the coronaviruses and all their variants have different protein spikes, with Delta having one that’s more efficient at getting around the vaccines. But the real problem is in the virus itself, not its protein shell, and why the most dangerous (MERS, SARS, and Covid-19) are so infectious. My independent research has found multiple one-in-a-million nucleotide sequence matches between all the coronaviruses and the human genome. Those sequences are the same as some of the loops of human tRNA. Using those loops and their amino acid code matches, viruses may be able to fool the nucleus membrane in cells to allow the virus to enter and associate with the human DNA, creating more opportunities for further infection. Our immune system may be compromised and may no longer be able to stop the virus and other diseases from attacking organs throughout the body. Vaccines that attack the virus protein shells while ignoring their contents are doomed to failure from the Darwin effect, but recognizing these loops suggests a possible approach to successful coronavirus vaccines. Only the infection process is considered in my work, not the innate virulence of the virus. For more info, check out this YouTube, Coronavirus – Using Your DNA Against You. https://www.youtube.com/watch?v=8dOIzD6ch8s