COVID-19, which originated in Wuhan, China, 2 years ago, became a pandemic, that continues to this day.

The Journal of Disaster Research (JDR) edited a special issue, “Special Issue on COVID-19 and Historical Pandemics” at the end of 2020 and an electronic version of the issue was published in January 2021 (JDR Vol.16, No.1, pp. 1-117).

Even though one year has passed, life has not yet returned to normal due to the continued spread of COVID-19. Although the percentage of the general public that has been vaccinated continues to increase and various drugs and treatments have been developed, the number of COVID-19 cases also continues to increase. A huge number of COVID-19 cases have been reported, especially in Europe and the Americas.

Accordingly, we planned to publish Special Issue Part 2 and called for papers.

This Special Issue Part 2 includes 18 manuscripts, which deal with general epidemiology, effects on socioeconomic or educational areas, and clinical medicine, including vaccines and medical treatments.

The virus spike protein plays an important role in its intrusion into human cells and the onset of COVID-19 infection. Although SARS-CoV-2 (the pathogenic virus of COVID-19) originated in Wuhan, China, various variant strains with mutation in gene coding in the spike protein have appeared in multiple countries. The WHO classifies these variants into the categories of VOC (variant of concern), VOI (variant of interest), or VUM (variant under monitoring).

The definitions of VOC and VOI are as follows. VOC: “A SARS-CoV-2 variant that meets the definition of a VOI and, through a comparative assessment, has been demonstrated to be associated with one or more changes in the degree of global public health significance.” VOI: “Increase in transmissibility or detrimental change in COVID-19 epidemiology, increase in virulence or change in clinical disease presentation, or decrease in effectiveness of public health and social measures or available diagnostics, vaccines and therapeutics.”

The WHO uses Greek letters designating the variants. Accordingly as they have appeared, variants have been designated as alpha (α: the UK variant), beta (β: the South Africa variant), and delta (δ: the Indian variant).

After the deadline for the manuscript of this special issue, a new variant, omicron (o) originated in South Africa and Botswana, and it immediately began spreading worldwide. Unfortunately, it was impossible to include the manuscript on the omicron variant in this Special Issue Part 2, as the deadline had already passed.

As COVID-19 continues to spread, the JDR will plan to edit Part 3 of this COVID-19 special issue.