It is critical to continue mitigation efforts to prevent the spread of COVID-19 and to cautiously reopen, considering the possibility of returning to an increase in social distancing.
Many viruses, such as the flu and common cold, tend to decrease in the number of cases in the summer and increase in the winter. However, when there is a new viral pandemic, this is not the case initially. Multiple factors make viruses, such as influenza, more common in the winter. These include the dry, cool climate, spending more time indoors, a decreased immune system likely due to lower vitamin D levels, and eventual immunity to the virus later in the season after infection. Children being out of school in the summer also decreases rates of transmission. COVID-19 will likely develop a seasonality, with a higher number of cases during times of low humidity and cooler weather. However, there are currently a high number of cases of COVID-19 in many countries, including those with warm and humid climates. With the high number of cases of this completely new virus with little population immunity, it is improbable that the spread of COVID-19 will slow significantly in the summer months. Additionally, experts at the University of Minnesota have predicted that there may be another surge in cases in the fall of 2020 at a higher level than the surge that occurred in the US in April. The surge prediction would mimic other influenza pandemics that started in March. It is, therefore, critical to continue mitigation efforts to prevent the spread of COVID-19 and to cautiously reopen, considering the possibility of returning to an increase in social distancing.