9 minutes

COVID, the Flu, RSV—It Has Been Quite the Fall Season

The research is clear: Our immune system works best when it is doing what it should—protecting us from microbes. Exposure to germs teaches the body the difference between harmful and harmless substances. A failure to do so increases the risk of autoimmune disease and frequent infections. The immune system needs to learn how to protect us, and without exposure to germs, a myriad of health problems can develop. 1 Last fall, the most problematic was a reduced collective immunity to viruses that cause upper respiratory tract infections.

The health measures used during the pandemic, that were meant to reduce the spread of COVID‑19, led to a decrease in exposure to otherwise normal respiratory viruses. This has weakened our collective immunity and left us more vulnerable to upper respiratory infections. In the fall of 2022, when sanitary measures were lifted, viruses began circulating again, and the effects were seen in schools and hospitals across Canada.

During the pandemic, Canada and many countries around the globe saw a near disappearance of influenza and respiratory syncytial virus (RSV) infections. 3 Of the more than 300,000 RSV tests performed in Canada between August 2020 and May 2021, only 239 were positive. In comparison, almost 20,000 tests had been positive the year before. Unfortunately, RSV made a comeback in North America in the summer of 2021. 4 This proved to be particularly problematic for young infants who depend on maternal antibodies against RSV for their first six months of life. Given that most mothers had not encountered RSV the year prior, maternal antibodies levels were lower than normal, leaving some children ill-equipped to face this surge in RSV. 5

After an RSV infection, the likelihood of reinfection is decreased by around 60% to 70% for a duration of approximately six months. 7 As seen in figure 2, RSV was quiescent during the 2020–2021 season, lowering our collective immunity against the virus. This left infants particularly vulnerable to RSV infection in subsequent years. Studies show that more than 80% of hospitalizations for RSV illness occur in infants less than a year old. 8 As seen in figure 3, hospitalisation rates for RSV are far greater this year compared to previous years. 9

In the case of the flu, immunity also wanes over time, although some studies show some level of lifelong protection to specific strains of the flu. 11 Still, figures 4 and 5 show inordinate hospitalization rates for the 2022–2023 flu season, both in the USA and Canada. 12

The reasons for the spike in hospitalizations are still not fully understood, but it is believed that lack of exposure to the virus in the last two years has led to more severe cases of the flu this year, especially in young children. Another reason for greater hospitalization rates is the dominant strain in circulation, H3N2, which is usually associated with more severe disease and higher transmissibility, especially in young children and older patients. 15

The good news is that, as seen in figures 5 and 6, flu activity in the general population, as well as in pediatrics, has become flat since the peak in November. 16

There is also good news when it comes to COVID‑19. As seen in figures 7 and 8, the rates of both infection and hospitalisation are currently relatively low. Additionally, it has been estimated that 90% of people in Canada have been infected at least once as of December 12, 2022. 18 According to the COVID‑19 Immunity Task Force in Canada, the rapid surge in infections can be attributed to the prevalence of the Omicron variant, which affected a minimum of 25 million individuals in the country. 19 It is likely we are now entering the endemic phase of COVID‑19. A pandemic shifts to endemic once the disease becomes more stable and manageable.

Tired of Being Sick and Tired?

Establishing a robust immune system starts by adopting a healthy lifestyle. Actions such as maintaining a healthy weight, abstaining from tobacco and alcohol, engaging in regular exercise, consuming a nutritious diet, getting adequate rest, and effectively managing stress all contribute to preventing infection or recovering faster from infections. 22,23,24,25,26

Plants and nutrients also offer a host of benefits for the immune system.

Andrographis continues to be highly regarded for its effectiveness in preventing and treating infections. Scientific studies have demonstrated that taking andrographis as a preventive measure for two months can reduce the likelihood of developing a cold by approximately 50%. 27 Additionally, research indicates that using andrographis while experiencing a cold leads to improvements in cold symptoms. 28,29,30 In the case of influenza patients, those who consumed a product containing andrographis extract experienced faster relief from symptoms compared to individuals using amantadine, a medication commonly used for flu symptom relief. Moreover, taking this product also appears to lower the risks of postinfluenza complications, including rhinosinusitis or bronchitis. 31

Elderberry extract has garnered support from multiple studies, highlighting its beneficial effects. Among flu patients, supplementation with elderberry led to an average recovery time that was four days shorter compared to those who did not take it. 32,33Additionally, when individuals started using an elderberry extract lozenge within 24 hours of experiencing symptoms, they experienced improved symptom relief within approximately 48 hours, compare to those who received a placebo.

Echinacea, a plant with a rich history of supporting the immune system, has been extensively studied and has shown promising results (see figure 9). This North American native plant has been the focus of three meta-analyses, revealing a notable reduction in the risk of developing a cold ranging from 10% to 58% when echinacea is taken. 34,35,36

Moreover, echinacea has demonstrated its ability to shorten the duration of infections. Studies have indicated that individuals taking echinacea experienced 26% fewer days with cold symptoms compared to those who did not. 37 This highlights the potential of echinacea to expedite recovery from colds.

Interestingly, echinacea has also shown effectiveness in children aged 4 to 12 years old. When supplemented for a duration of four months, echinacea resulted in a 30% reduction in the occurrence of cold symptoms, a 52% reduction in respiratory complications, and a significant 62% decrease in antibiotic prescriptions when compared to a regimen of vitamin C at 50 mg three times daily. 38 These findings underscore the potential benefits of echinacea supplementation in promoting better health outcomes for children.

Oral zinc also helps improve symptoms in adult cold sufferers. Oral zinc is effective in reducing the duration of common cold symptoms in adults by an average of three days. 40,41,42,43,44

Références
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