Despite the end of winter, respiratory viruses maintain positivity above 50% in Chile, with influenza A as the main cause. Experts attribute this rise to post-pandemic changes and waning vaccine immunity. Authorities urge vaccination and preventive measures.
Although spring brings warmer temperatures, with forecasts up to 32 degrees, respiratory viruses continue to affect Chile's population. According to the latest Instituto de Salud Pública (ISP) report, 52% of 3,829 samples from sentinel centers tested positive. Influenza A leads with 774 cases (35.2%), especially in children aged 5-14, followed by rhinovirus with 573 cases (26.1%), parainfluenza (270 cases, 12.3%), metapneumovirus (171, 7.8%), adenovirus (125, 5.7%), and Covid-19 (119, 5.4%).
Jorge Vilches, head of Epidemiology at the Ministry of Health, stresses: “although nearly 8 million people are already vaccinated against influenza, we continue to reiterate the call to protect oneself with this vaccine for those who have not yet done so. It is very important to understand that the focus and greatest risk in this spring is influenza, which, within viral circulation, continues to have greater preponderance even beyond winter”.
Immunologist Alexis Kalergis from the Catholic University explains that “this increase in respiratory infections during spring months has been observed in previous years and also in the northern hemisphere, especially after the Covid-19 pandemic, which generated important changes in the seasonality of respiratory viruses and which is still in the process of normalizing”. The vaccination campaign started on March 1, 2025, reaching 8.1 million doses by late September, with 77.78% coverage in eight of twelve target groups. Kalergis adds that immunity may be waning, urging prompt vaccination.
Infectologist Carlos Pérez from Universidad San Sebastián reports consultations for flu-like symptoms in adults, such as fever, cough, and fatigue, often in family outbreaks, but “in general, they are cases that require rest, but have not been severe or required hospitalization”. Influenza cases concentrate in 5-14 year olds, while rhinovirus affects under 1-4 years more. Vilches reminds of measures like hand washing, mask use, and avoiding crowds.