While COVID hasn’t even completely disappeared, there are signs that the annual flu epidemic is fast approaching. How can we take better care of ourselves and our colleagues?
Epidemiologists predict that after two “quieter” years, a more intense flu epidemic is likely to return in the winter of 2022-23. The reduction in the number of cases of influenza is of course linked to the COVID pandemic, as the tools for protecting against the pandemic are the same as the precautions that are effective against influenza. As long as the majority of people observed the rules of social distancing and increased hygiene, routinely using masks, the seasonal flu virus had no chance.
However, the absence of a flu epidemic in 2020 and 2021 is not a clearly positive development and could have unpleasant consequences. Experts believe that the two flu-free years may have led to a decrease in community protection and herd immunity, making us less resistant to the virus strains attacking us this year and less protected. The number of cases and complications may also increase.
December to February is the main flu season
Every winter, the flu epidemic arrives almost on schedule. Mass outbreaks of respiratory illness are caused by the emergence of RNA viruses, a type of influenza virus of the Orthomyxoviridae family. The types are designated A, B and C and are subdivided into subtypes based on the glycoproteins of the viral envelope surrounding the RNA, the antigens most responsible for generating the antibody response, namely haemagglutinin (H) and neuraminidase (N). Common recurrent subtypes are, for example, A(H1N1), A(H1N2) and A(H3N2). Of the types, it is mainly types A and B that cause disease in humans, with type A causing more widespread epidemics. Over the past two years, several subtypes of influenza B have become less common.
The symptoms of influenza are familiar to everyone: the respiratory symptoms of the common cold, nasal congestion, nasopharyngitis, cough and sore throat are accompanied by chills, fever, headache, muscle and joint pain in the extremities. Influenza is debilitating, causing lethargy, fatigue, weakness and the risk of over-infection, as the body, weakened by influenza viruses, can be more easily attacked by other pathogens (e.g. pneumococcal bacteria). Complications, such as pneumonia, are a particular risk for the elderly or those with a chronic illness.
Why is there a flu epidemic every year?
Influenza viruses spread rapidly by droplet infection and can be expected to attack practically every year. Viral strains are not stable, so viruses are highly variable, and by the time we have developed immunity to one type of virus, we are no longer dealing with exactly the same pathogen. The structure of the antigen, haemagglutinin, is constantly changing, which means that after the change, the new variant can infect people who have already had a flu infection or acquired immunity to it through vaccination in the previous year.
This phenomenon is called antigenic drift or antigenic shift. The spread of influenza viruses is monitored by the WHO, the World Health Organisation, which uses reports of cases to recommend which virus strains should be used in the current three- or four-component vaccine that year.
Methods of protection
The best way to protect against influenza is to administer a topical vaccine each year. It is particularly recommended for people whose work brings them into contact with many people and who are at high risk of infection, or for those whose immune defences are weaker because of age, living situation, chronic illness and who are at high risk of complications. The vaccine should be administered in late autumn so that immunity is established by the beginning of the influenza pandemic.
If the outbreak is prolonged and continues into February and March, a booster vaccination is recommended for people with immunodeficiency. Vaccination does not provide full immunity, but it is effective in mitigating the course of the disease and helping to avoid serious complications for those who become infected despite vaccination. Individual protection can be enhanced by strengthening the body’s defence system in general. Physical activity in fresh air, a healthy diet rich in vitamins and effective stress relief are recommended.
The most common complications and prevention of flu
In old age, with chronic illness (heart, lung, kidney, diabetes and obesity), the risk of bacterial over-infection is high. Pneumococcal pneumonia is the most common of these. Symptoms of pneumonia may include recurrent fever, headache, abdominal discomfort, shortness of breath, cough and weakness. On physical examination, there is a listening abnormality over the lungs, and the diagnosis may be confirmed by a chest X-ray. In a severe, rapidly deteriorating condition, hospitalisation is necessary and the patient may not be saved despite antibiotic treatment.
There is a vaccine against severe pneumococcal infection
Vaccination against pneumococcal disease is recommended for the risk factors listed above. The so-called conjugate vaccine containing 13 antigens is used first, followed within 2-12 months by the so-called polysaccharide vaccine containing 23 antigens. These vaccines can be administered at the same time as the influenza and COVID vaccines or at any interval.
Small workplace epidemiology
Everyone can do a lot individually to prevent the spread of infection. It would be a shame to forget the protective methods learned during COVID! Frequent hand-washing, physical contact, hand-holding, avoiding touching, proper spacing, correct use of tissues and wearing masks can protect against infection carried by droplets deposited on utensils and released into the air through coughing and sneezing.
By taking these simple precautions, we can protect ourselves and our staff. It needs to be said again and again, because unfortunately it is not common practice to go to work or to other communities and public places when you are ill! Anyone who has symptoms of infection, coughing, sneezing, fever, should stay at home and, if possible, take advantage of the home office and, if possible, try to get well as soon as possible on bed rest.
Flu usually heals itself in a week, but it is best to use cough and headache relievers to ease the symptoms. As it is a viral infection, antibiotics are ineffective against it and are only needed if the illness is prolonged and there is a bacterial overgrowth.