Under the title "Summer Cold is the Harshest This Year.. Immunity Experts Explain Why," the website Alhurra published a translated article from The New York Times, indicating that as many countries relax the restrictions and precautionary measures imposed to combat the COVID-19 pandemic, this summer is expected to witness the worst wave of influenza and cold illnesses in a long time.
Infectious disease experts explained that several factors are increasing the spread of cold illnesses this summer, which is experiencing heat waves in many parts of the world. Experts noted that humans' immune systems have missed the opportunity to be exposed to many microbes that people were regularly confronted with in public transportation, workplaces, or during public gatherings in streets, shopping centers, and entertainment venues due to precautionary measures against the COVID-19 pandemic. Consequently, according to the experts, the human immune system is not as strong as it used to be, which slows down its response to face germs and viruses. They pointed out that although exposure to viruses in the past granted many a lasting immunity, isolation and lack of interaction have contributed to the weakening of that immunity.
In this regard, Paul Skolnick, an immunology virus specialist and head of internal medicine at the Virginia Tech Carilion School of Medicine, stated: "Repeated exposure to many pathogens activates the immune system to be ready to respond to this pathogen." He added, "If you have not been exposed to those factors, your immune system will be a bit slower to respond or may not respond fully, leading to increased infections with some respiratory illnesses for a longer time and with stronger symptoms."
The U.S. Centers for Disease Control and Prevention (CDC) mentioned that cases of common respiratory viruses, including respiratory syncytial virus (RSV) and human influenza viruses, which cause traditional cold and flu symptoms, are on the rise this summer. A spokesperson for the CDC noted that the increase in RSV cases, which can pose a particular risk to children under two years old and the elderly, is unusual for this time of year, with many young children being hospitalized after displaying severe symptoms.
Additionally, Europe, South Africa, Australia, and New Zealand have seen a rise in RSV infections due to lockdowns that weakened immunity against that illness. Su Huang, director of the National Influenza Center at the World Health Organization in New Zealand, explained that the strict restrictions imposed by the country not only stopped the novel coronavirus but also eliminated respiratory syncytial virus and seasonal influenza virus for the past twenty years. However, when New Zealand opened its borders to Australia, cases of RSV appeared within weeks, affecting a larger-than-usual group of children, many of whom were hospitalized.
Huang affirmed that she has not seen "anything like this in her 20 years of working with viruses," adding, "Usually there is some degree of pre-existing immunity in people due to the winter preceding summer, but this time the virus spread like wildfire." On her part, Catherine Edwards, a pediatric medicine professor at Vanderbilt University Medical Center, noted that it has become difficult to identify which cold viruses are infecting adults during this period, as the symptoms are similar, making it challenging to know if a patient is carrying RSV, rhinovirus, parainfluenza viruses, or other cold viruses.
Moreover, Satya Dandekar, an expert in viral infections and mucosal immunity, pointed out that although isolation measures do not weaken the immune system, other factors, including stress, poor sleep habits, and increased alcohol consumption, can play a role in how an individual's immune system responds to respiratory viruses. Dandekar, who also heads the Department of Medical Microbiology and Immunology at the University of California, indicated that there would be a massive varied response in the community regarding who will respond well and deal with infections and who will fall ill.
In the same context, Allison Agu, an infectious disease specialist at Johns Hopkins Children's Center, emphasized the necessity for people to take the necessary precautions to prevent the spread of all respiratory illnesses, especially as COVID-19 preventive measures are relaxed. She continued: "I will say the same things we might say to fifth graders: wash your hands and use tissues when sneezing or cover your mouth with your elbow and practice other hygiene measures, along with needing to get vaccinated against COVID-19 so you don't panic when you catch a cold."
Meanwhile, epidemiologist at Princeton University Rachel Baker expressed concern about the potential for the simultaneous spread of influenza viruses, such as RSV, and coronavirus. She noted that she is currently experiencing her own summer cold, which she assumes she caught when she went to a local bar to watch the recent football match between England and Italy, but felt safe having been fully vaccinated against COVID-19.
