Immune Systems Advisor

Evidence Review • Oral Health • Microbiome Mouthwash can reduce plaque, gingivitis, bad breath and tooth decay—but some antimicrobial formulations also alter the oral microbiome. What does the evidence really tell us about chlorhexidine, nitric oxide, blood pressure, diabetes and long-term health? Quick Answer Mouthwash is neither universally harmful nor universally necessary. Therapeutic mouthrinses can provide meaningful dental benefits, particularly for people with gingivitis, plaque, elevated cavity risk or specific dental conditions. However, antimicrobial rinses can also alter the oral microbial ecosystem. The important distinction is between demonstrated dental benefits and hypotheses about long-term systemic effects . Current evidence does not establish that routine mouthwash use causes hypertension, diabetes, cardiovascular disease or Alzheimer's disease. Evidence status: ...

Medically reviewed by: OneDayMD Editorial Team | Last updated: August 2026 Introduction The rapid development and deployment of COVID-19 vaccines have been monumental in combating the global pandemic, saving countless lives and enabling societies to regain a sense of normalcy. Central to the efficacy of many of these vaccines, particularly mRNA and viral vector-based ones, is the spike protein—a key component of the SARS-CoV-2 virus that facilitates its entry into human cells. By instructing the body to produce a version of this protein, vaccines train the immune system to recognize and neutralize the virus without causing illness. However, as vaccination campaigns expanded, so did public curiosity and concern about the spike protein's role, fueled by a mix of scientific complexity, misinformation, and distrust. For years, the public was told that COVID-19 mRNA vaccine components degraded rapidly—within days to weeks. Hulscher, McCullough, and colleagues' ...

Written by Dr. Frank Yap, MD · Immune Systems Advisor · Last medically updated September 2026 Quick Answer Alpha-gal syndrome (AGS) is a delayed allergy to red meat and other mammal-derived products, triggered by a tick bite — most often from the lone star tick ( Amblyomma americanum ) in the United States. Unlike most food allergies, symptoms such as hives, stomach cramping, or full anaphylaxis usually appear 2 to 8 hours after eating beef, pork, lamb, or other mammalian products, which makes AGS notoriously easy to miss. A 2026 CDC study found that up to 31% of adults in the highest-risk states carry alpha-gal antibodies, though the agency's official estimate for people with the full clinical allergy remains around 450,000 nationwide . There is no cure, but strict avoidance of alpha-gal-containing products and preventing further tick bites lead to meaningful improvement for many patients over time. In This Guide What Is Al...