What Makes mRNA Vaccines So Effective Against Severe COVID-19?

COVID Vaccine Effective Response Success

COVID-19 Vaccine

Shots trigger exceptional antibody response by activating key helper immune cells.

The first two vaccines created with mRNA vaccine technology — the Pfizer/BioNTech and Moderna COVID-19 vaccines — are arguably two of the most effective COVID vaccines developed to date. In clinical trials, both were more than 90% effective at preventing symptomatic infection, easily surpassing the 50% threshold the Food and Drug Administration had set for COVID-19 vaccines to be considered for emergency use authorization.

While breakthrough infections have increased with the emergence of the delta and omicron variants, the vaccines remain quite effective at preventing hospitalizations and deaths. The success of the new technology has led scientists to try to figure out why mRNA vaccines are so effective and whether the protection they provide is likely to endure as new variants arise.

A new study from researchers at Washington University School of Medicine in St. Louis and St. Jude Children’s Research Hospital shines light on the quality of the immune response triggered by mRNA vaccines. The study shows that the Pfizer vaccine strongly and persistently activates a kind of helper immune cell that assists antibody-producing cells in creating large amounts of increasingly powerful antibodies, and also drives the development of some kinds of immune memory. Known as T follicular helper cells, these cells last for up to six months after vaccination, helping the body crank out better and better antibodies. Once the helper cells decline, long-lived antibody-producing cells and memory B cells help to provide protection against severe disease and death, the researchers said.

Further, many of the T follicular helper cells are activated by a part of the virus that doesn’t seem to pick up mutations, even in the highly mutated omicron variant. The findings, published online December 22, 2021, in the journal Cell, help explain why the Pfizer vaccine elicits such high levels of neutralizing antibodies and suggest that vaccination may help many people continue producing potent antibodies even as the virus changes.

“The longer the T follicular helper cells provide help, the better the antibodies are and the more likely you are to have a good memory response,” said co-corresponding author Philip Mudd, MD, PhD, an assistant professor of emergency medicine at Washington University. “In this study, we found that these T follicular helper cell responses just keep going and going. And what’s more, some of them are responding to one part of the virus’s spike protein that has very little variation in it. With the variants, especially delta and now omicron, we’ve been seeing some breakthrough infections, but the vaccines have held up very nicely in terms of preventing severe disease and death. I think this strong T follicular helper response is part of the reason why the mRNA vaccines continue to be so protective.”

The first antibodies produced in response to an infection or vaccination tend not to be very good. B cells need to go through a kind of boot camp in so-called germinal centers in the lymph nodes before they can produce really powerful antibodies. T follicular helper cells are the drill sergeants of these boot camps. The helper cells provide instruction to the antibody-producing cells on making ever more potent antibodies and encourage those with the best antibodies to multiply and, in some cases, turn into long-lived antibody-producing cells or memory B cells. The longer the germinal centers last, the better and stronger the antibody response.

Earlier this year, Ali Ellebedy, PhD, an associate professor of pathology & immunology, of medicine and of molecular microbiology at Washington University, reported that, nearly four months after people had received the first dose of the Pfizer vaccine, they still had germinal centers in their lymph nodes that were churning out immune cells directed against SARS-CoV-2, the virus that causes COVID-19.

In this latest study, Mudd and co-corresponding authors Ellebedy and Paul Thomas, PhD, of St. Jude, aimed to understand the role of T follicular helper cells in producing such a strong germinal center response. The research team also included co-first authors Anastasia Minervina, PhD, and Mikhail Pogorelyy, PhD, postdoctoral researchers who work with Thomas at St. Jude, and others.

The researchers recruited 15 volunteers who each received two doses of the Pfizer vaccine three weeks apart. The volunteers underwent a procedure to extract germinal centers from their lymph nodes 21 days after the first dose, just before the second dose; then at days 28, 35, 60, 110, and 200 after the initial dose. None of the volunteers had been infected with SARS-CoV-2 at the start of the study. The researchers obtained T follicular helper cells from the lymph nodes and analyzed them.

The researchers now are studying what happens after a booster dose and whether changes to T follicular helper cells could explain why people with compromised immune systems, such as those with HIV infection, do not mount a strong antibody response.

Reference: “SARS-CoV-2 mRNA vaccination elicits a robust and persistent T follicular helper cell response in humans” by Philip A. Mudd, Anastasia A. Minervina, Mikhail V. Pogorelyy, Jackson S. Turner, Wooseob Kim, Elizaveta Kalaidina, Jan Petersen, Aaron J. Schmitz, Tingting Lei, Alem Haile, Allison M. Kirk, Robert C. Mettelman, Jeremy Chase Crawford, Thi H. O. Nguyen, Louise C. Rowntree, Elisa Rosati, Katherine A. Richards, Andrea J. Sant, Michael K. Klebert, Teresa Suessen, William D. Middleton, the SJTRC Study Team, Joshua Wolf, Sharlene A. Teefey, Jane A. O’Halloran, Rachel M. Presti, Katherine Kedzierska, Jamie Rossjohn, Paul G. Thomas and Ali H. Ellebedy, 23 December 2021, Cell.
DOI: 10.1016/j.cell.2021.12.026

5 Comments on "What Makes mRNA Vaccines So Effective Against Severe COVID-19?"

  1. hahahahahahahahaha
    The most waxinated people in the World, Israel, vactinated its citizens with fourth dose and now they change its strategy and going to a model of mass infection because vactination dont working…

  2. Howard Jeffrey Bender, Ph.D. | December 30, 2021 at 5:39 am | Reply

    All the coronaviruses and all their variants have different protein spikes, with Delta and Omicron having spikes that are 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

  3. Wow someone is desperate for their funding from big pharma or The Gates Foundation. What absolute garbage. So forget the record cases, forget the injuries in teens and horrible effects of the gene therapy. To call this a vaccine is either incompetant, corrupt or misinformation

  4. Our healthcare system is about to experience a tsunami! Potential side effects of jabs include chronic inflammation, because the vaccine continuously stimulates the immune system to produce antibodies. Other concerns include the possible integration of plasmid DNA into the body’s host genome, resulting in mutations, problems with DNA replication, triggering of autoimmune responses, and activation of cancer-causing genes. Alternative COVID cures exist. Ivermectin is one of them. While Ivermectin is very effective curing COVID symptoms, it has also been shown to eliminate certain cancers. Do not get the poison jab. Get Ivermectin while you still can https://medicalfreedom.wiki

  5. From 3 coments after mine, 2 of them wrote someone who think with its own head, not Faucis or Bill Gates head. Bravo!
    Best link for Ivermectin: https://covid19criticalcare.com/ivermectin-in-covid-19/

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