COVID-19 cases rising in Finland amid summer conditions

Summer is generally a time when respiratory illnesses are less common than in other seasons. However, COVID-19 infections began to rise earlier this summer, with the peak expected to occur later. Reports from July coincided with the Olympic Games, and the U.S. Centers for Disease Control and Prevention noted that COVID-19 spikes have also been observed in summer months.

Professor Olli Vapalahti, a virologist at the University of Helsinki, remarked that it’s challenging to make long-term conclusions about the frequency of COVID-19 peaks since the virus has only been known for four years. Factors such as virus mutations, population immunity, and the simultaneous circulation of various variants have influenced its seasonality.

Traditionally, viruses like influenza and RSV exhibit marked seasonality, with epidemics typically occurring in winter. Vapalahti noted that the conditions that facilitate the spread of SARS-CoV-2 are similar to those of other respiratory viruses. While influenza has been monitored for decades, the current trends indicate a slight summer rise in COVID-19 cases, without the intense wave experienced last winter.

According to Leif Lakoma, a senior physician at the Finnish Institute for Health and Welfare (THL), there is still limited understanding of COVID-19’s behavior. Although summer has seen increased cases of SARS-CoV-2, other respiratory viruses, including RSV, have not shown similar activity. Statistically, reported cases represent only a small fraction of total infections, as many go untested when they don’t require hospitalization.

Lakoma emphasizes that autumn and winter present conditions favorable for viral spread, as more people congregate indoors. He anticipates a rise in COVID-19 cases in the fall, but it remains to be seen whether this will happen early in the season or later. Vaccinations for vulnerable groups are set to start in late August or early September.