How will COVID-19 affect the coming flu season?
Just as the world is anticipating the end of the COVID-19 pandemic, experts warn the public against the upcoming flu season. Although much was unknown about how SARS-CoV-2 would interact with other respiratory viruses such as influenza and respiratory syncytial virus (RSV), seasonal influenza has virtually vanished in many countries throughout the COVID-19 pandemic. However, with the world increasingly removing pandemic measures and people returning to their normal activities, influenza has once again started to circulate around the world and experts now agree that we can expect an influenza season this year. Read along to learn more about the upcoming influenza season, its interaction with the current state of the COVID-19 pandemic, and ways to protect yourself.
What causes influenza?
Commonly known as flu, influenza is a prevalent and highly infectious respiratory disease caused by different types of influenza viruses. According to the World Health Organization (WHO), 5 – 10% of adults and 20 – 30% of children contract influenza, resulting in 3−5 million cases of severe disease and up to 650,000 deaths each year. Influenza viruses are single-stranded segmented RNA viruses of the family Orthomyxoviridae, which primarily spread by droplets or respiratory secretions of infected individuals. As typically observed with RNA genome viruses, influenza virus mutates rapidly, frequently, and continuously through antigenic drifts and antigenic shifts within its genetic material.
Influenza A, B, C, and D are the four types of influenza viruses which have been so far identified. Among these, Influenza A and B are recognized as the only types of influenza types to cause human disease of any concern. Probably deriving from its high mutation rate and extensive host range, influenza A has proved to be capable of causing pandemics and large epidemics. Major outbreaks linked to different subtypes of influenza A include Spanish Flu (1918), Asian Flu (1957), Hong Kong Flu (1968), Bird Flu (2004), and Swine Flu (2009). Whereas influenza B have been linked to some epidemics, the subtype has never been reported to cause a pandemic. With the latter affecting solely cattle and swine populations, influenza C and influenza D have never been associated with significant symptoms or outbreaks in humans
Is the COVID-19 pandemic over?
Although the COVID-19 pandemic is not over yet, the number of new cases, hospitalizations, and deaths has significantly decreased in many parts of the world. Indeed, according to Worldometer, number of daily new COVID-19 cases has reduced to 459,856 mostly steadily following a peak of 3,846,075 new cases recorded on January 21, 2022. However, many experts recommend keeping up to date with vaccines and boosters, arguing that low vaccine coverage and testing rates characterizing various countries provide ideal conditions for new and potentially more dangerous variants to emerge. Efforts to continue surveillance, develop more efficient vaccines, and producing more accurate and tailored diagnostic solutions remain critical for the world to get ready to overcome potential challenges posed by COVID-19 in the future.
How is COVID-19 expected to affect the approaching flu season?
Whereas the first influenza season since the onset of the pandemic was nearly non-existent in many countries, several experts warn that the upcoming flu season may be characterized by a simultaneous rise in COVID-19 and influenza cases, which is sometimes referred to as a “twindemic”. Throughout much the pandemic, many people had much lower levels of exposure to influenza viruses to have built up sufficient immunity against them due to measures such as wearing masks, social distancing, travel restrictions, and minimizing public contact. Experts warn that the abandonment of these measures combined with reduced levels of public immunity against influenza may result in a more severe flu season. Moreover, according to preliminary data by the Australian Department of Health and Aged Care, influenza has demonstrated earlier and higher peaks in 2022 than any of the previous 5 flu seasons in Australia. Although there is significant concern on whether the upcoming flu season in the Northern Hemisphere would mirror the current flu season within the Southern Hemisphere, some experts suggest that COVID-19 and influenza are more likely to rise sequentially than simultaneously thanks to a phenomenon known as viral interference, which occurs when infection with a certain virus decreases the risk of contracting another.
What is respiratory syncytial virus (RSV)?
Respiratory syncytial virus (RSV) is a negative-sense, single-stranded RNA virus of the family Pneumoviridae. It is the most widespread cause of respiratory infections and respiratory hospitalization in infants younger than 1 year of age. The severity and clinical presentation of RSV may vary from mild upper respiratory disease to severe lower respiratory disease. Although the virus can cause severe illness in those with weak or immunocompromised immune systems, including young children and the elderly ,many healthy adults and children typically recover after experiencing cold-like symptoms such as congested/ runny nose, dry cough, fever, sore throat, headache, and sneezing.
What can you do to protect yourself?
While healthy individuals typically recover without need for additional treatment, eating a healthy diet, resting, and staying hydrated can shorten the recovery process. Various antiviral treatment options such as zanamivir, peramivir, and oseltamivir are also available for the treatment of more severe influenza infections. Alongside treatment options, there is also a seasonal flu vaccine composed of both influenza A and influenza B. Although influenza vaccines have to be upgraded each year based on estimations regarding the approaching flu season, various studies have shown that particularly in seasons where vaccine viruses are similar to circulating viruses, influenza vaccination can significantly reduce the risk of flu-related disease, hospitalization, and complications. Today, influenza remains among the most consequential vaccine-preventable diseases worldwide. Especially for people at risk of developing severe disease, experts recommend vaccination each year before the onset of the flu season to ensure maximum immunity.
Finally, as the signs and symptoms of influenza, common cold, RSV, and COVID-19 can be highly similar, the clinical diagnosis of these infections may be challenging. Diagnostic tests prove to be even more critical for the prevention of onward transmission and the initiation of optimal treatment during periods such as the flu season where multiple of such pathogens may be circulating simultaneously. In order to address these needs, our RapidFor™ SARS-CoV-2 Rapid Antigen Test Kit, Influenza A/B Rapid Test Kit, and RSV Rapid Test Kit help healthcare professionals to quickly check for one of these infections, whereas our RapidFor™ SARS-CoV-2 & FLU A/B Antigen Combo Test Kit and SARS-CoV-2 + FLU A/B + RSV Combo Test Kit allow for their simultaneous detection and differentiation in minutes.