{"id":176062,"date":"2025-11-15T15:00:00","date_gmt":"2025-11-15T12:00:00","guid":{"rendered":"https:\/\/bukvaved.top\/v-chjom-raznica-mezhdu-virusami-grippa-a-i-v\/"},"modified":"2026-10-28T15:35:58","modified_gmt":"2026-10-28T12:35:58","slug":"v-chjom-raznika-mezhduzhduvirusami-grippa-aiv","status":"publish","type":"post","link":"https:\/\/bukvaved.top\/en\/v-chjom-raznica-mezhdu-virusami-grippa-a-i-v\/","title":{"rendered":"What is the difference between influenza A and B viruses?"},"content":{"rendered":"<p><strong>Influenza A and influenza B are infections caused by two different types of influenza virus: type A is found in humans and many animals, is divided into subtypes (e.g. H1N1, H3N2), mutates more rapidly and is the only type that causes pandemics, while type B circulates almost exclusively among humans and mutates more slowly.<\/strong> The symptoms of both types are very similar and cannot be distinguished based on the course of the infection itself\u2014only testing can determine the difference. Treatment and vaccination cover both types.<\/p>\n<p> To sum it up<\/p>\n<ul>\n<li> <strong>Carrier viruses:<\/strong> Influenza A virus infects humans, birds, pigs, and other animals; influenza B virus infects mainly humans.<\/li>\n<li> <strong>Separation:<\/strong> Type A has subtypes designated by the letters H and N, type B has no subtypes, only lines (Victoria and Yamagata).<\/li>\n<li> <strong>Variability:<\/strong> Viruses mutate faster and are the only ones that have caused influenza pandemics.<\/li>\n<li> <strong>Symptoms and treatment:<\/strong> They are practically the same \u2013 the type is determined by analysis, and the decision on drug treatment is made by the doctor.<\/li>\n<\/ul>\n<h2> Influenza A and B viruses \u2013 what\u2019s the difference?<\/h2>\n<p> There are four known types of influenza virus: A, B, C and D. Seasonal epidemics among people are caused by <strong>only types A and B.<\/strong> Type C usually causes mild infections and does not lead to epidemics, while type D mainly affects cattle.<\/p>\n<p> Viruses <strong>influenza A<\/strong> Influenza viruses are classified by two proteins on their surface: hemagglutinin (H) and neuraminidase (N). According to the U.S. Centers for Disease Control and Prevention (CDC), there are 18 known H and 11 N subtypes, and combinations of these are found predominantly in wild birds. Subtypes A(H1N1) and A(H3N2) currently circulate regularly among people. Other subtypes, such as those from birds, can occasionally be transmitted to humans.<\/p>\n<p> Viruses <strong>influenza B<\/strong> have no subtypes; they are divided into two lines: <strong>B\/Victoria and B\/Yamagata<\/strong> . According to the CDC and WHO, Yamagata lineage viruses have not been detected in circulation since March 2020.<\/p>\n<h2> Viral variability and pandemics<\/h2>\n<p> Influenza viruses are constantly changing through small mutations (called <strong>antigenic drift<\/strong> ). This is why the vaccine is updated every season, and a previous flu infection does not provide lifelong protection. According to the CDC, group B viruses change more slowly than group A viruses, especially compared to A(H3N2).<\/p>\n<p> Influenza A viruses can also undergo rapid change when genes from viruses originating from different hosts, such as birds, pigs, and humans, are mixed ( <strong>antigenic shift<\/strong> ). This creates a virus to which the majority of the population has no immunity. Only influenza A viruses have caused pandemics\u2014an example is the 2009 influenza A(H1N1) pandemic. Influenza B viruses, which circulate almost exclusively among humans, do not have such an animal reservoir.<\/p>\n<h2> Symptoms of influenza A and B \u2013 can they be distinguished?<\/h2>\n<p> No. Both forms usually begin suddenly and can lead to:<\/p>\n<ul>\n<li> fever and chills,<\/li>\n<li> muscle and joint pain, headache,<\/li>\n<li> dry cough, sore throat, runny nose,<\/li>\n<li> severe fatigue and weakness.<\/li>\n<li> Children are also more likely to experience vomiting or diarrhea.<\/li>\n<\/ul>\n<p> The common belief that influenza B always presents a &quot;mild&quot; course is an oversimplification. Both types of the virus can cause severe illness and complications, such as pneumonia. The course of the disease depends more on a person&#039;s age and health than on the virus itself. Those at risk include young children, the elderly, pregnant women, and people with chronic illnesses and weakened immune systems.<\/p>\n<table>\n<tbody>\n<thead>\n<tr>\n<th> Characteristic<\/th>\n<th> Influenza A<\/th>\n<th> Influenza B<\/th>\n<\/tr>\n<\/thead>\n<\/tbody>\n<tbody>\n<tr>\n<td> <strong>Who does this infect?<\/strong><\/td>\n<td> People and birds, pigs and other animals<\/td>\n<td> Mostly people<\/td>\n<\/tr>\n<tr>\n<td> <strong>Separation<\/strong><\/td>\n<td> Subtypes H and N, such as H1N1, H3N2<\/td>\n<td> Victoria and Yamagata lines (no subtypes)<\/td>\n<\/tr>\n<tr>\n<td> <strong>The pace of change<\/strong><\/td>\n<td> Faster<\/td>\n<td> Slow down<\/td>\n<\/tr>\n<tr>\n<td> <strong>Pandemics<\/strong><\/td>\n<td> Yes, that&#039;s the only type that called them.<\/td>\n<td> NO<\/td>\n<\/tr>\n<tr>\n<td> <strong>Seasonal epidemics<\/strong><\/td>\n<td> Yes<\/td>\n<td> Yes<\/td>\n<\/tr>\n<tr>\n<td> <strong>Symptoms<\/strong><\/td>\n<td> Typical for the flu<\/td>\n<td> The typical form of flu is indistinguishable from it without a test.<\/td>\n<\/tr>\n<tr>\n<td> <strong>Seasonal vaccine<\/strong><\/td>\n<td> Contains strains A(H1N1) and A(H3N2).<\/td>\n<td> Contains the B\/Victoria strain (also B\/Yamagata in quadrivalent vaccines).<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<h2> Influenza A and B testing, treatment and vaccination.<\/h2>\n<p> The type of virus is determined using a swab from the nose or throat. <strong>rapid antigen tests<\/strong> (often in combination, which separately detect influenza A and B viruses, and sometimes COVID-19), as well as more accurate <strong>molecular tests<\/strong> , such as real-time PCR. A negative rapid test result does not always rule out the flu \u2013 it&#039;s best to trust a doctor to interpret it.<\/p>\n<p> Treatment for both types is the same: rest, plenty of fluids, fever-reducing and pain-relieving medications, and, for some patients, antiviral drugs that target viruses A and B. Their use is at the doctor&#039;s discretion; they are most effective when administered early. Antibiotics are not effective against influenza viruses.<\/p>\n<p> The flu vaccine protects against both types. <strong>Tetravalent<\/strong> The vaccines contained two A strains and both B lineages. Since the Yamagata lineage was no longer detected, WHO experts concluded that its presence in vaccines was no longer justified and recommended <strong>trivalent<\/strong> vaccines (two A strains and two B\/Victoria strains). Your doctor or pharmacist will advise you which vaccine is available for a given season.<\/p>\n<h2> When should you see a doctor?<\/h2>\n<p> Regardless of influenza A or B, the following symptoms require urgent medical attention: shortness of breath or chest pain, high fever that persists for several days, a recurrence of fever after a temporary improvement, confusion, signs of dehydration, and worsening of a chronic condition. People in high-risk groups should consult a doctor at the first sign of symptoms\u2014this is when antiviral treatment is most appropriate.<\/p>\n<h2> Frequently Asked Questions (FAQ)<\/h2>\n<p> <strong>Which flu is worse \u2013 A or B?<\/strong><\/p>\n<p> Influenza A has a high epidemic potential and is the only type capable of causing pandemics, but both types can cause severe illness in the same person. The risk depends primarily on age and underlying medical conditions.<\/p>\n<p> <strong>Is it possible to get influenza A and B in the same season?<\/strong><\/p>\n<p> Yes. Having one type of the virus does not protect against the other, because they are different viruses. The seasonal vaccine protects against both types.<\/p>\n<p> <strong>How can I tell if I have influenza type A or B?<\/strong><\/p>\n<p> Only with a swab, rapid antigen test, or molecular test (such as real-time PCR). It&#039;s impossible to determine this based on symptoms.<\/p>\n<p> <strong>Is the treatment for influenza A and B different?<\/strong><\/p>\n<p> No. Symptomatic treatment is the same, and antiviral medications used for influenza are effective against both types of the virus. Their use remains at the discretion of the doctor.<\/p>\n<p> <strong>What is the influenza A H1N1 and H3N2 virus?<\/strong><\/p>\n<p> These are subtypes of the influenza A virus, named for variations in the surface proteins hemagglutinin (H) and neuraminidase (N). Both viruses currently circulate among humans and are included in seasonal vaccines.<\/p>\n<h2> See also<\/h2>\n<ul>\n<li> What is the difference between a vaccine and a serum?<\/li>\n<li> What is the difference between quarantine and isolation?<\/li>\n<li> What is the difference between HIV and AIDS?<\/li>\n<li> What is the difference between asthma and COPD?<\/li>\n<\/ul>","protected":false},"excerpt":{"rendered":"<p>Influenza A and influenza B are infections caused by two different types of influenza virus: type A is found in humans and<\/p>","protected":false},"author":1,"featured_media":176063,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[67,20],"tags":[70],"class_list":["post-176062","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-vopros-otvet","category-fakty","tag-chem-otlichaetsya"],"_links":{"self":[{"href":"https:\/\/bukvaved.top\/en\/wp-json\/wp\/v2\/posts\/176062","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/bukvaved.top\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/bukvaved.top\/en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/bukvaved.top\/en\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/bukvaved.top\/en\/wp-json\/wp\/v2\/comments?post=176062"}],"version-history":[{"count":1,"href":"https:\/\/bukvaved.top\/en\/wp-json\/wp\/v2\/posts\/176062\/revisions"}],"predecessor-version":[{"id":176064,"href":"https:\/\/bukvaved.top\/en\/wp-json\/wp\/v2\/posts\/176062\/revisions\/176064"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/bukvaved.top\/en\/wp-json\/wp\/v2\/media\/176063"}],"wp:attachment":[{"href":"https:\/\/bukvaved.top\/en\/wp-json\/wp\/v2\/media?parent=176062"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/bukvaved.top\/en\/wp-json\/wp\/v2\/categories?post=176062"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/bukvaved.top\/en\/wp-json\/wp\/v2\/tags?post=176062"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}