The COVID-19 pandemic might have faded from the news headlines, but for most scientists and international health officials, the debate is not yet through. One of the key questions still keeps cropping up in 2025: How much time do COVID-19 vaccines actually confer immunity, and should we expect to need regular booster doses like the flu?New evidence indicates the immunity we gain from COVID-19 vaccines—particularly the mRNA varieties—may not be as long-lasting as we had envisioned. Why? Because a so-called long-lived plasma cell has proven to be surprisingly evasive.Vaccines like the tetanus shot offer robust protection for up to a decade. That’s because they trigger the formation of long-lived plasma cells in the bone marrow—cells that "remember" the pathogen and generate antibodies rapidly if you’re exposed again.Conversely, COVID-19 vaccines, even though they have been successful in lowering severe disease and hospitalization, appear to come up short in reaching this gold standard of immune memory. A recently published study in Nature Medicine (September 2024) by Dr. F. Eun-Hyung Lee of Emory University explains why protection wanes months after vaccination, even in individuals who received multiple doses and have had prior infections.The Emory research included 19 healthy adults between the ages of 20 and 65 who had been given two to five doses of mRNA COVID-19 vaccinations. Their bone marrow samples were studied by researchers up to 33 months after the first vaccination using a method known as flow cytometry to identify and examine various forms of antibody-making cells.What they found was revealing: while the bone marrow had an abundance of short-lived antibody-secreting cells specific to the SARS-CoV-2 virus, the long-lived plasma cells—those responsible for sustained immunity—were nearly absent. Even in individuals who had recently recovered from COVID-19 or received updated booster shots, these long-lived immune defenders remained scarce.Conversely, the same bone marrow samples had a strong presence of long-lived plasma cells for tetanus and influenza—vaccines with longer-lasting protection. The disparity could be one reason why breakthrough infections still appear relatively soon after COVID-19 vaccination.How Effective Is The COVID Vaccine?The Emory results accompany a wider meta-analysis appearing in JAMA Network Open (May 2024), which compared 40 worldwide studies to determine real-world vaccine effectiveness over time. The analysis spanned different waves, such as Delta and Omicron.Effectiveness against symptomatic COVID-19 was approximately 53% one month following full vaccination.The highest effectiveness was reported by Moderna's vaccine at 62%, followed by Sinovac's lowest at 32%.Six months after that, effectiveness fell to 14%, and at nine months, it fell another step to only 9%.Booster shots restored protection to 60% for a brief time, but that too fell to 13% in nine months.Those are the numbers that make it plain: both primary series and booster shots provide temporary barriers, but their protection wanes—particularly with the newer, more immune-evading variants of the virus, such as Omicron.Should You Get a Booster Shot?The answer is complicated. If you're in a vulnerable group—older people, those with compromised immune systems, or frontline healthcare workers—then yes, booster shots are still a critical line of defense against severe illness and hospitalization. But even for the general population, boosters provide added protection for a limited but important time frame.What is also important is that which strain the booster aims against. Similar to the flu vaccine, efficacy greatly relies on how closely the vaccine and the prevailing strain align. The FDA is currently collaborating with researchers to define the predominant strain for the next COVID-19 vaccine season—potentially marking the beginning of an annual, strain-specific booster approach.The holy grail for SARS-CoV-2 vaccine scientists today is how to trigger long-lived plasma cells. Dr. Lee's research implies that existing mRNA platforms might not be the ideal vehicle for it—at least, not yet. But research is exploring new delivery modes, different schedules, and even combination vaccines that could eventually solve the secret to durable COVID-19 immunity."Long-lived plasma cells are the secret to enduring protection," according to Dr. Lee. "What our findings indicate is that the existing mRNA vaccines fail to produce them well for COVID-19. More studies are necessary to alter that."Ways to Build Immunity NaturallyBoosting your immune system naturally can make your body fight off infections and diseases more efficiently. These are easy, evidence-based methods to support immune health:Consume a well-balanced diet with leafy vegetables, citrus fruits, berries, garlic, and turmeric.Drink lots of water and herbal teas to stay hydrated.Exercise frequently with a minimum of 30 minutes of moderate physical activity every day.Sleep well (7–8 hours) to enable your body to repair and recharge.Reduce stress through meditation, yoga, or conscious breathing.Avoid alcohol and smoking, which can compromise immunity.