[{"data":1,"prerenderedAt":-1},["ShallowReactive",2],{"$fxLN3MUwXCdr5RPjwZYIDpOj8CHyjOmngWTgoKXPtZbg":3,"$fwXaYowc5Fz0PjBOQBv7SyBIywVydFH_D6BQyDWhlicU":32,"$f3Ft0rKFJHppdzE-vuveecxx1BUcg9iOlMLtyzf_MJDg":60},[4,8,12,16,20,24,28],{"title":5,"slug":6,"path":7},"About Microbeonline.com","about-microbeonline-com","\u002Fabout-microbeonline-com\u002F",{"title":9,"slug":10,"path":11},"About Me","about-me","\u002Fabout-microbeonline-com\u002Fabout-me\u002F",{"title":13,"slug":14,"path":15},"Advertise with Us","advertise-us","\u002Fadvertise-us\u002F",{"title":17,"slug":18,"path":19},"Privacy Policy","privacy-policy","\u002Fprivacy-policy\u002F",{"title":21,"slug":22,"path":23},"Abbreviations","abbreviations","\u002Fabbreviations\u002F",{"title":25,"slug":26,"path":27},"Microbes","microbes","\u002Fmicrobes\u002F",{"title":29,"slug":30,"path":31},"Books","recommended-books","\u002Frecommended-books\u002F",{"type":33,"data":34},"blog",{"slug":35,"title":36,"description":37,"seoTitle":38,"seoDescription":38,"author":39,"createdDate":40,"lastUpdatedDate":41,"draft":42,"category":43,"image":38,"body":44,"faq":45,"tags":58,"related":59},"why-is-common-cold-so-common","Why Is the Common Cold So Common? The Role of Serotypes and Immune Specificity","Over 160 rhinovirus serotypes plus five other virus families mean your immune memory is always one step behind the next cold.",null,"Acharya Tankeshwar","2013-07-06","2026-07-02",false,"general-microbiology","Most people get two to four colds per year. Some get more. And yet, after each one, the immune system does exactly what it is supposed to do; it makes antibodies, clears the infection, and holds onto the memory of that pathogen. So why does the next cold arrive anyway?\n\nThe common cold is not one disease. It is the collective name for upper respiratory infections caused by at least six different virus families: rhinoviruses account for roughly 25–30% of cases, followed by coronaviruses (common-cold strains, not SARS-CoV-2) at around 10%, with parainfluenza viruses, respiratory syncytial virus, adenoviruses, and influenza viruses making up most of the remainder. Each of these families contains multiple serotypes (distinct antigenic variants that the immune system treats as separate pathogens). Antibodies made against one serotype of rhinovirus provide little or no protection against a different serotype of the same virus, let alone against a completely different virus family.\n\nThis is the core reason the common cold recurs throughout a person's lifetime: there are simply more variants circulating than the immune system can accumulate memory for.\n\nYou must be aware of how common it is. Everyone has some understanding or experience of the common cold. You might be suffering from a common cold right now or might have suffered earlier. This is the evidence to prove that the common cold is so common; the question arises, why is the common cold so common?\n\nTo answer this question, you need some background knowledge **about host-pathogen interaction.**\n\n![common cold so common](https:\u002F\u002Fassets.microbeonline.com\u002Fblogs\u002Fcommon-cold-so-common.jpg)Figure: common cold so common\n\nEach infectious disease results from a long battle between your immune system and the virulence factor (disease-causing capacity of) pathogens. When those pathogens overwhelm your immune system, you suffer from a disease, but if your immune system controls the pathogens, you become immune, or the resolution of the disease occurs. To win this battle (host-pathogen interaction), your body uses various weapons known as [immune cells](\u002Fcells-of-the-immune-system\u002F) and their mediators, such as T Cells, B Cells, antibodies, natural killer cells, interferons, [cytokines](\u002Fshort-note-cytokines\u002F), macrophages, etc. Similarly, pathogens also employ various virulence factors that either destroy these weapons (e.g., [IgA](\u002Fimmunoglobulin-iga-structure-functions\u002F) protease), help them to hide from immune cells, or inactivate the effect of these cells.\n\nAs the common cold has multiple etiological agents, primary infection (an infection occurring for the first time) by each of these pathogens is possible. But [antibodies ](\u002Fimmunoglobulin-structure\u002F)and memory cells (formed after primary infection) are expected to protect us from these pathogens’ secondary infection. One of the immune system’s notable characteristics is that the antibodies and memory cells are type-specific; i.e., the antibodies or memory cells formed against X pathogen **may protect us from that X pathogen** but not **others.**\n\n![colds are viral](https:\u002F\u002Fassets.microbeonline.com\u002Fblogs\u002Fcolds-are-viral-300x300.png)Figure: colds are viral\n\nIn the case of a common cold caused by rhinovirus, our body synthesizes antibodies and neutralizes or inactivates that virus whenever we get infected. Some antibodies are stored in our body to kill\u002Fneutralize if the same rhinovirus attacks our body again. But if the new rhinovirus (with a changed antigenic structure) attacks our body, already synthesized antibodies and memory cells may not recognize and remove\u002Fneutralize this virus. So we again suffer from a common cold. Now, our body synthesizes new antibodies for this new type of rhinovirus, and the process continues.\n\nVirologists have identified more than **160 serotypes** of rhinovirus, classified across three species: rhinovirus A, B, and C. This property; multiple antigenically distinct variants of the same virus; is called **serotyping**, and rhinovirus's 160+ serotypes are a key reason the common cold cannot be prevented by a single vaccine.\n\nAnother virus with a related but even more dramatic strategy is the [influenza virus.](https:\u002F\u002Fmicrobeonline.com\u002Finfluenza-flu-virus-structure-classification\u002F)",[46,49,52,55],{"question":47,"answer":48},"Why can't scientists make a vaccine against the common cold?","Rhinoviruses alone have over 160 antigenically distinct serotypes, and several other virus families also cause cold symptoms. A vaccine would need to confer protection against all of them — a practically impossible target given how many variants exist and how quickly some of them change.",{"question":50,"answer":51},"Why do children get more colds than adults?","Children have had fewer cold infections in their lifetime, meaning fewer serotype-specific immune memories have accumulated. Each new cold encounter is a genuinely first encounter for more serotypes. Adults have built up partial immunity to a greater range of variants over years of exposure, though they still get colds because the pool of variants is larger than what any one person can accumulate immunity to.",{"question":53,"answer":54},"If the cold is viral, why do doctors sometimes prescribe antibiotics for it?","This is a prescribing error driven by patient expectations and diagnostic uncertainty — not evidence-based practice. Antibiotics have no activity against the viruses that cause the common cold. Their use in this context contributes to antimicrobial resistance without benefiting the patient.",{"question":56,"answer":57},"Is the \"cold weather causes colds\" belief true?","Partially, indirectly. Cold viruses are not more active in cold weather per se, but rhinoviruses replicate best at around 33°C — the temperature of the nasal passages — making the upper respiratory tract an ideal niche. Additionally, people spending more time indoors in close contact during cold months increases transmission opportunities, contributing to seasonal cold patterns.",[],[],[61,67,74,79,83,87,92,97,101,105],{"slug":62,"name":39,"description":63,"image":64,"body":65,"postCount":66},"acharya-tankeshwar","Editor-in-chief","https:\u002F\u002Fassets.microbeonline.com\u002Fauthors\u002Ftankeshwar-acharya-author-microbeonline.jpg","***Tankeshwar Acharya, MSc (Medical Microbiology)***\n\n*Tankeshwar Acharya is an Assistant Professor in the Department of Microbiology at Patan Academy of Health Sciences (PAHS), Nepal, where he has been teaching and practicing clinical microbiology for over 14 years. He is the founder of Microbe Online, one of the leading free microbiology education resources on the web, covering bacteriology, mycology, parasitology, immunology, and clinical laboratory diagnostics written from direct experience in both the classroom and the diagnostic laboratory.*",433,{"slug":68,"name":69,"description":70,"image":71,"body":72,"postCount":73},"ashma-shrestha","Ashma Shrestha","SEO Copywriter and Science Communicator\nKathmandu, Nepal","https:\u002F\u002Fassets.microbeonline.com\u002Fauthors\u002Fashma-shrestha.png","Ashma Shrestha holds a Master of Science in Medical Microbiology from the Institute of Science and Technology (IOST), Tribhuvan University, Nepal, where she developed a strong foundation in virology, molecular biology, and diagnostic microbiology.\n\nShe now works as an SEO Copywriter at Resolution Digital, where she combines her scientific training with research-driven content strategy. She is certified in Google Analytics and Google Business Profile (GBP), and brings a data-informed approach to science communication writing content that is not only accurate but structured to reach and serve the students who need it most.\n\nAt microbeonline, Ashma contributes articles primarily in virology and molecular biology, areas she finds most compelling for their mechanistic depth and their growing clinical relevance. Her writing reflects the same standard the site is built on: factual rigor, clear explanation of the *why* behind microbiology concepts, and content that helps students move from memorization to genuine understanding.\n\nShe is passionate about making complex microbiological concepts accessible without sacrificing accuracy; a skill that sits at the intersection of her scientific training and her professional work in content and SEO.",81,{"slug":75,"name":76,"description":77,"image":38,"body":38,"postCount":78},"sushmita-baniya","Sushmita Baniya","Author \u002F Contributor",32,{"slug":80,"name":81,"description":77,"image":38,"body":38,"postCount":82},"samikshya-acharya","Samikshya Acharya",20,{"slug":84,"name":85,"description":77,"image":38,"body":38,"postCount":86},"alisha-tripathi","Alisha Tripathi",6,{"slug":88,"name":89,"description":90,"image":38,"body":38,"postCount":91},"aastha-shrestha","Aastha Shrestha"," Author \u002F Contributor",10,{"slug":93,"name":94,"description":95,"image":38,"body":38,"postCount":96},"guest-author","Guest Author","Guest Author \u002F Contributor",2,{"slug":98,"name":99,"description":77,"image":38,"body":38,"postCount":100},"srijana-khanal","Srijana Khanal",18,{"slug":102,"name":103,"description":95,"image":38,"body":38,"postCount":104},"dr-poonam-acharya","Dr. Poonam Acharya",1,{"slug":106,"name":107,"description":77,"image":38,"body":108,"postCount":109},"nisha-rijal","Nisha Rijal","**Nisha Rijal** is a microbiologist and quality assurance specialist. She served for nearly 12 years as a microbiologist at the National Public Health Laboratory (NPHL), Nepal's national reference laboratory, and continues to work as a consultant microbiologist in international public health organization. ",51]