Table 2 Lay summary of this review

This narrative review, conducted by an international team of scientists with different backgrounds, is illustrative of the complexities of public health, policymaking, and risk communication with the public in health emergencies such as the ongoing pandemic. Here, we focus on false dichotomies, which refer to claims or positions erroneously presented as two simplistic and polarized options. While there have been many false dichotomies about SARS-CoV-2 and COVID-19, we chose six:

False dichotomy 1. It has been said that health and the economy are on opposite poles, but this is not true. Public health and economic experts agree that supporting workers and businesses financially is key to tackling the pandemic. Sensible public health strategies that reduce the spread of the virus reduce the health and economic harms of the pandemic.

False dichotomy 2. Discussion about response measures has pitted indefinite lockdown against unlimited reopening, but a more nuanced response is needed. While no single intervention is a silver bullet, there are many tools in our COVID-19 response kit that can be used together to further reduce risk. Response plans must be tailored to local COVID-19 levels, vaccination levels, among other issues, with a clear plan for how response measures are evaluated and implemented. Education and harm reduction are effective and sustainable approaches in the long term.

False dichotomy 3. The dichotomy symptomatic vs. asymptomatic is simplistic. There are different stages of infection and a broad spectrum of disease manifestations in the body. About four in five infected individuals develop COVID-19 symptoms. Cases are substantially spread by infected people both when they have symptoms and when they do not. Relying exclusively on symptom-based strategies for controlling the spread of SARS-CoV-2 seems insufficient and other interventions are needed.

False dichotomy 4. Referring to absolutes such as droplets vs. aerosols or airborne vs. non-airborne is inaccurate. Respiratory particles exist on a continuum rather than as a dichotomy. The primary transmission mode of SARS-CoV-2 is close contact with respiratory particles. Surface transmission is a minor mode of transmission. Long-range aerosol transmission occurs in specific conditions such as prolonged exposure, enclosed spaces, and inadequate ventilation.

False dichotomy 5. Masks and face coverings are effective preventive tools but are not faultless. While mask wearing is a complex intervention, there is consistent evidence that demonstrates their effectiveness to reduce the spread of the virus. Policies must be clearly communicated and include aspects such as the scenarios where they are most useful (crowded and indoor spaces) and the importance of wearing well-fitted masks and continuing education efforts to increase adherence.

False dichotomy 6. SARS-CoV-2 reinfection is rare but does occur. Reinfection can be confused with persistence of virus components in the body after infection or with reactivation of virus hidden in some body organs. Differentiating these phenomena is not easy. Evidence supports protection from reinfection for at least 6–12 months after a first infection episode. Reinfections are expected to occur only in some individuals, likely caused by fading or insufficient immunity.

Nuance is critical in risk communication with the public and for policymaking in public health. We must recognize that there are not only two options in our understanding of COVID-19 and the public health response.