New Delhi: As the globe shifts toward the endemic phase of COVID-19, fresh variants and sub-lineages of the Omicron variant keep arising (some of the prevalent variants in India: LF.7 series, XFG series, JN.1 series, and NB.1.8.1 series). Although the widespread effect of the virus has become less severe, clinicians and scientists are cautioning the public not to underestimate even low-grade symptoms, particularly low-grade fever, as harmless. On top of this changing landscape is increasing interest in the association of COVID-19 with gastrointestinal upset, as well as the growing role of RNA vaccines in the intestinal immune system.
In an interaction with News9Live, Dr. Debojyoti Dhar, Co-Founder and Director at Leucine Rich Bio (BugSpeaks), listed the forgotten symptoms of Omicron and how it has changed amid rising cases.
Low-Grade Fever: No Longer a Mere Minus Symptom
Throughout most of the initial pandemic, high-grade fever was regarded as a hallmark symptom of COVID-19. The Omicron variants have shifted the clinical picture entirely, however. Low-grade fever (99–100°F), sore throat, body aches, and fatigue are now the routine symptoms in the majority of cases, usually confused with mild flu or cold.
What is troubling is that individuals with low-grade fever might not quarantine or test themselves, thus hastening transmission. Even in immunocompromised persons or those with comorbid conditions, these milder manifestations can lead to complications. Healthcare providers now advise increased watchfulness for any recurring low-grade fever, particularly if associated with gastrointestinal symptoms, fatigue, or shortness of breath.
The Gut-COVID Connection: A New Focus
New studies are uncovering the gastrointestinal effects of COVID-19. Many Omicron patients increasingly and progressively complained about nausea, diarrhoea, abdominal cramps, and loss of appetite. It is not by coincidence. SARS-CoV-2 adheres to the ACE2 receptors, which are widespread in the gastrointestinal tract. Experiments and data show that the virus persists in the gut for weeks, disrupting the microbiome and causing inflammatory responses. It’s a broad-reaching implication, especially in long COVID, where there are ongoing belly complaints. It’s now clear the gut’s not a bystander—it’s the key battleground in the body fighting the virus.
RNA Vaccines and Gut Immunity – What Comes Next?
mRNA vaccines such as those developed for COVID-19 have been revolutionary. By causing cells to produce an innocuous spike protein, they stimulate the immune system to develop antibodies. While their initial impact is systemic, researchers are now learning how these vaccines might also affect mucosal and gut immunity.
Following vaccination, some have had brief gastrointestinal side effects—mild nausea, bloating, or a change in bowel movement. While generally transient, they suggest a possible interaction between vaccine-induced response and gut environment. Research has suggested that the gut microbiome changed as a result of receiving the Pfizer-BioNTech mRNA vaccine for COVID-19. The researchers also confirmed that study participants with high or low responses to the COVID-19 vaccine had unique gut microbiome signatures or profiles. A high vaccine response means that a person’s immune system is more likely to be able to protect them against COVID-19.
In the long run, knowing this gut-vaccine connection could lead to RNA-based treatments for gastrointestinal illness beyond COVID-19—consider Crohn’s disease, ulcerative colitis, or even colorectal cancer.
The Way Forward – Integrative Vigilance
We are moving into an era where COVID-19 might no longer be the story that grabs headlines, but its clinical transformation still deserves notice. Noticing subtle changes, such as the importance of low-grade fever or symptoms in the gut, can signal early infections and avoid complications. Meanwhile, pushing research on RNA vaccine technology and its effects on gut immunity promises a larger future in which vaccines can be designed not only to prevent disease, but also to promote general immune and gut health.
As public health narratives evolve, so too must our approach—less panic-driven, more informed, and integrative. In this new normal, the gut may be just as crucial a player in pandemic resilience as the lungs ever were.
mRNA vaccines such as those developed for COVID-19 have been revolutionary. By causing cells to produce an innocuous spike protein, they stimulate the immune system to develop antibodies. While their initial impact is systemic, researchers are now learning how these vaccines might also affect mucosal and gut immunity. Health News Health News: Latest News from Health Care, Mental Health, Weight Loss, Disease, Nutrition, Healthcare
