COVID-19 pandemic

2020 pandemic caused by SARS CoV 2 virus. Many scientists were anticipating and warning about a pandemic[^billgatestedtalk] and there exists fairly accurate estimates of the loss from the pandemic (Fan2018pandemic)

One surprise of this pandemic was that many rich, scientifically advanced countries botched the response while many poorer countries have managed it much better. For instance, take a look at this article: What the US can learn from how African countries handled Covid.

It also teaches a lot about Epidemic surveillance testing.



Mode of spreading and prevention efforts

The transmission through large droplets and the surface has been identified as the important concern at the beginning. Although evidence for airborne, aerosol-based transmission has been mounting, a lot of efforts has been misdirected. Instead of focusing on ventilation, deep cleaning, flexiglass, etc. have been highly active.

Zeynep Tufekci has been talking about this issue. e.g., his thread on a mystery transmission from New Zealand. (Eichler2021transmission)

Social Inequality of pandemic

Meausring outbreaks

It is not trivial to accurately measure the scale of the outbreaks. At the early stage, there was not enough testing capacity and people did not know about the disease. Furthermore, there is a lot of asymptomatic COVID-19 infections.

Using sewage was an alternative population-level measurement method.

See Measurement

Modeling epidemic

Economic implications

Healthcare implications

Elimination vs. mitigation

Elimination vs


A study claimed that the biggest source of misinformation has been the president Donald Trump1, who publicly touted many unproven therapies. See Internet Searches for Unproven COVID-19 Therapies in the United States

See also Hydroxychloroquine. The rise and fall of (you know what) walks through the issues with Hydroxychloroquine and Ivermectin.

An important infodemic is about vaccines. COVID 19 vaccine

In Korea, a retired professor 이왕재 produced a lot of misinformation.

Social media


Perra2021nonpharmaceutical reviews non-pharmaceutical interventions.

This pandemic highlighted the effectiveness of Mask wearing for airborne diseases.

Application of Deep learning