Specific health issues are often omnipresent throughout the cold days of the year, and influenza is one of them. There are four types of flu: A, B, C, and D, with the first two being the chief causes of seasonal flu epidemics since they can be easily spread in contact with an infected individual. Influenza type B is spread particularly among humans and can be transmitted via droplets while talking or sneezing. Despite the public that believes influenza A is more harmful as the initiator of many large-scale pandemics, influenza B viruses are similarly potential threats. They have been distinguished since 1940 and constantly evolved, though at a lower rate. Anyhow, the two types of influenza B viruses still co-circulate to this day shoulder to shoulder with two influenza A viruses. As such, FDA-approved influenza vaccines protect against all four viruses. Read on to learn more about influenza B lineages, the symptoms, and the influenza vaccine.
Influenza B Classification
Like other influenza types, influenza B is a negative-strand RNA virus containing ribonucleic acid. Some other viruses with similar structures include Ebola disease, polio, measles, hepatitis C virus (HCV), and Covid-19. As a member of the virus family Orthomyxoviridae and the only species of the genus Betainfluenzavirus, influenza B shares common grounds with influenza A. Nonetheless, there are structural differences. The classification for influenza B viruses is founded in two lineages, namely Yamagata (B/Yamagata/16/88-like) and Victoria (B/Victoria/2/87-like). This is while the influenza B virus used to spread as a homogeneous group, and the classification came to pass not until the 1980s. The difference border between B/Yamagata and B/Victoria is vague to a reasonable extent; symptoms are alike, and it is hard to tell which is more severe. Yet, B/Victoria viruses show more tendency to infect younger people than the B/Yamagata lineage, whilst records show relatively more infections with either of the lineages in older children and younger adults. Apart from these lineages, we can break down this classification by going further into clades and sub-clades.
Influenza B Past Pandemics
Flu pandemics occur along with the introduction of a new influenza virus strain. This antigenic difference is due to reassortment and antigenic drift. During such variations, proteins on a virus’s surface mutate, and the novel combination will be unrecognizable from the present antibodies. That being said, the mutation rate of influenza B viruses is relatively moderate due to its host range being limited to humans and seals. In consequence, influenza B viruses have not contributed to widespread pandemics of flu disease.
Differences between Influenza A and B Viruses
The similarities between influenza A and B viruses exceed the difference far more. In terms of structure, they have filamentous or spherical shapes with almost exact lengths and diameters. Both are RNA viruses and contain eight segments of single-stranded RNA. On top of that, the symptoms are often identical, if not different in severity. However, the most notable difference lies in the host range, as influenza A viruses can spread among a diversity of animals. In contrast, influenza B viruses are transmitted only from person to person and sometimes among seals. That clarifies the bolder presence of influenza A viruses in the course of pandemics. Nevertheless, it would be a mistake to take influenza B’s slighter severity for granted. The A(H3N2) virus is considered the deadliest among the four abovementioned viruses. However, we should not think of influenza B as domicile since both influenza B types usually result in more severe symptoms than the A(H1N1) virus.
Influenza B Symptoms
The earlier you notice the symptoms, the higher your chance of getting rid of the troubles of the flu. It usually takes about two days for influenza B symptoms to pop up, though it could be longer as well. The most prevalent indicators are chills, fever (temperature above 37.8ºC), fatigue, and sore throat. In addition to these, you may have to put up with muscle aches, sneezing, runny nose, and headaches. Diarrhea and vomiting can also come along with the flu, more commonly in children. Though rarely, influenza B can lead to seriously severe conditions if left untreated. Diseases like respiratory failure, pneumonia, inflammation of the heart (myocarditis), and bronchitis are some of the possible complications.
Transmission Routes and Prevention
Influenza B is readily spread from person to person via droplets made during sneezing, coughing, or simply talking. Objects such as door knobs, tables, and phones can also be contaminated. To make it worse, influenza viruses can find their way to other hosts before symptoms appear. Though a threat to everyone, influenza B can bring about more acute consequences in sensitive groups or those with weakened immune systems, such as kids, the elderly, and people with chronic health conditions. Besides, pregnant women are at a high risk of infection. The most suitable way to guarantee robust immunity against influenza B viruses is the flu vaccination suggested every year. Moreover, simple habits of steering away from infected people, staying home when you are sick, and keeping your hands clean can be effective in keeping yourself and the community around you safe and healthy.
Treatment
Approaches to influenza depend on specific criteria like age, general health condition, and past experiences with the flu. In case the influenza B symptoms seem light, you can go with moderate home remedies. Taking a few days off from work to get enough rest is essential. Dehydration is oftentimes a given when the flu holds onto you, so ensure you take lots of fluids. Traditional drinks like honey and tea, plus anything containing vitamin C, can also help. On the other hand, certain groups with weakened immune systems must take a further step by taking prescribed medications in order to prevent lasting complications. The most commonly prescribed treatments are painkillers and antiviral drugs to alleviate the pain and the symptoms while helping the body stand against the viruses. Centers for Disease Control and Prevention (CDC) has approved a few antivirals, including zanamivir (Relenza®), oseltamivir (Tamiflu®), and peramivir (Rapivab®). Worthy of remark, antibiotics are best for bacterial infections; they do not contribute to your recovery procedure for influenza B and may only have harmful side effects.
Best Influenza Vaccines
The influenza vaccine offers the most entrusted protection against influenza since they pinpoint specific viruses. Viruses from both B/lineages circulate during the flu season along with the A(H3N2) and A(H1N1) viruses, and quadrivalent influenza vaccines introduce all four kinds to the immune system. WHO and CDC recommend that everyone 6 months and older get the influenza vaccine every year. The typical type is the traditional flu shots available in a variety of options, taken from standard-dose shots to an adjuvanted shot to a recombinant shot. In addition, people 2-49 years old can take advantage of the nasal spray (LAIV) vaccines if taking an injection is much of a burden to bear. Though health insurances cover the cost of the influenza vaccine in most countries, some have to pay charge ranging from about $35 to $80 more.
The Biosimilar Influenza Vaccine
Because of the flu viruses’ persistent mutation, a yearly dose of influenza vaccine is recommended, whereas the costs seem too much of a dead weight for some people. Concerning the lack of easy access to such medication in some regions, like developing countries, some pharma companies have begun to devote more time and resources to biosimilar medications. They function similarly to biologic medicines and vaccines, with the same side effects and administration routes. Opal Biopharma (OBP), for example, is one of the leading companies in the niche and actively seeks new approaches toward the betterment of biosimilar products, including the biosimilar influenza vaccine.
Final Thoughts
Influenza type B is the second most common type of influenza and one of the major causes of seasonal flu epidemics. Humans are the only reservoirs of influenza B, as well as seals. Thus, the mutation speed is significantly less than influenza A viruses, which justifies the influenza B exculpation from widespread influenza pandemics. Some commonplace indicators of influenza B include fever, sore throat, muscle aches, chills, fatigue, and runny nose. Moreover, as one of the main targets of influenza B, children may experience stomach symptoms such as abdominal pain, nausea, and diarrhea. Other sensitive groups are also advised to be cautious with the flu, like the elderly and people with health conditions such as liver or kidney disorders, HIV, asthma, heart disease, and so forth. Aside from actions included in CDC guidelines for prevention, such as washing hands and keeping away from infected individuals, the influenza vaccine is the optimal way to ensure sufficient immunity. Along with various flu shots and the nasal spray vaccine, you can also plump for more economical biosimilar vaccines.
