At the end of December 2019, a series of hospitalized patients in Wuhan, China, reported cases of pneumonia and respiratory failure caused by a new coronavirus (SARS-CoV-2). The rapid spread of the disease led to the identification of the virus on January 7, and Wuhan was placed under quarantine on January 23. The World Health Organization declared the outbreak a “Public Health Emergency of International Concern” (PHEIC), its highest level of alert at the time. In March, with more than 118,000 cases in 110 countries, the WHO recognized the outbreak as a global pandemic.

Since then, COVID-19 has become a global challenge, impacting millions of lives and prompting diverse governmental responses worldwide. On February 11, 2020, the WHO officially named the virus COVID-19 (Coronavirus Disease, 2019), and despite containment efforts, the disease continued to spread across Asia, the Middle East, and Europe.

The measures to contain the virus’s spread were subject to intense debate. In the United States, Dr. Anthony Fauci, a leader in the pandemic response, was a central figure in implementing social distancing policies. Fauci, known for his work in the fight against HIV/AIDS, faced strong criticism in the U.S. Congress in June 2024, particularly regarding his recommendation of social distancing.

The size of respiratory droplets plays a crucial role in COVID-19 transmission. Larger droplets (>5 microns) fall quickly onto nearby surfaces and are responsible for short-range transmission, while aerosols (<5 microns) remain airborne and can travel greater distances, posing a higher risk in enclosed, poorly ventilated spaces.

Initially, it was believed that larger droplets were the primary carriers of the virus, leading to less strict distancing measures and the use of looser fabric masks. However, by 2021, scientists began to understand that the virus also spread through aerosols, underscoring the importance of proper ventilation and more effective mask usage.

This episode teaches us that scientific conclusions must be interpreted cautiously, as recommendations can vary depending on study contexts. Extrapolations should be supported by additional research.