Coronavirus disease 2019 (COVID-19) emerged as a new contagion during December 2019, since which time it has triggered a rampant spike in fatality rates worldwide due to insufficient medical treatments and a lack of counteragents and prompted the World Health Organization to declare COVID-19 a public health emergency. It is, therefore, vital to accelerate the screening of new molecules or vaccines to win the battle against this pandemic. Experiences from previous epidemiological data on coronaviruses guide investigators in designing and exploring new compounds for a safe and cost-effective treatment. Several reports on the severe acute respiratory syndrome (SARS) epidemic indicate that severe acute respiratory syndrome coronavirus (SARS-CoV) and the novel COVID-19 use angiotensin-converting enzyme 2 (ACE2) as a receptor for binding to the host cell in the lung epithelia through the spike protein on their virion surface. ACE2 is a mono-carboxypeptidase best known for cleaving major peptides and substrates. Its degree in human airway epithelia positively correlates with coronavirus infection. The treatment approach can be the neutralization of the virus entering lung epithelial cells by using sera containing antibodies collected from COVID-19–recovered patients. Hence, we herein propose a pulmonary aerosolized formulation or a nasal drop using sera, which contain antibodies to prevent, treat, or immunize against COVID-19 infection.