Prof Kingston Mills
Professor of Experimental Immunology and Director Trinity Biomedical Institute
Trinity College Dublin, Irish Society for Immunology Scientific Advisory Committee member
Winter is here, and with it comes an increased risk of respiratory infectious diseases. To defend ourselves against attacks from nasty microbes, we should get vaccinated.
Respiratory infections are more prevalent in winter because we spend more time indoors and our resistance is lower. Respiratory microbes are spread by coughing and sneezing, and transmission is facilitated by close contact with an infected person. Colder temperatures and exposure to wet conditions can compromise the immune response, making it harder for our immune system to fight the microbes.
Respiratory viruses and bacteria
In addition to the common cold, influenza virus (flu) and respiratory syncytial virus (RSV) infections are more prevalent in winter and can cause serious diseases in infants and older people. Covid-19¸ which can be fatal in older individuals and those with underlying medical conditions, is also set to become a seasonal disease with a resurgence in winter months.
Infection with the bacteria Group A streptococcus (Strep A) that causes sore throats is more common in winter, and rare life-threatening complications of infection can occur — for example, scarlet fever. Pneumococcus infection, also more common in winter, affects the lungs and can cause pneumonia, septicaemia and meningitis.
Respiratory infections are more prevalent
in winter because we spend more time
indoors and our resistance is lower.
Vaccines prevent respiratory infectious diseases
Apart from good hygiene, wrapping up and avoiding soakings in the wet winter days, what can we do to reduce our risk of respiratory infections? The answer is, where possible, to get vaccinated.
In Ireland, flu and pneumococcal vaccines are available for those over 65. A nasally-delivered flu vaccine is also recommended for 2–12 year olds. The over-50s, pregnant women, individuals with long-term health conditions and healthcare workers should all get boosted with the latest Covid-19 vaccine. A vaccine against RSV has recently been developed that can protect babies born to vaccinated mothers, and this should soon be available in Ireland. These vaccines protect against severe respiratory diseases, and most also prevent infection and transmission of the microbes. Although not without some risks, vaccines are the most effective interventions for the control of infectious diseases in humans.