key: cord-0958057-k62z7rf4
authors: Lee, Jong-Koo
title: How to deal with the Delta variant this fall
date: 2021-08-26
journal: Osong Public Health Res Perspect
DOI: 10.24171/j.phrp.2021.0217
sha: 65e55f6aa66676e17c8d04f136a15bd617073124
doc_id: 958057
cord_uid: k62z7rf4

nan

contact history, NPIs remain an effective preventive measure until the vaccination complete rate rises to 60% or more. Misguided messaging can cause confusion among the public, like in the US. The introduction of premature mitigation policies without evidence and in the absence of a high vaccine uptake rate will lead to an absolute increase in the number of patients, which will increase the number of fatalities.

Third, mutations have resulted in an increased transmission rate, meaning that the expanded reproduction ratio has changed from 2-3 to 4-6; thus, the vaccination rate required to establish herd immunity is likely to increase to 80% (1-1/ R 0 ). In addition, children under 12 years of age (about 5.72 million people, as of 2015 in the Republic of Korea) cannot currently be vaccinated. Therefore, if the Delta variant becomes predominant, herd immunity will be difficult to achieve. In particular, children under the age of 12 should be protected by wearing a mask and social distancing. It is urgently necessary to take rapid steps to vaccinate family members of unvaccinated children and teachers to block the epidemic in schools, as children can transmit the infection.

Fourth, although peer review has not been conducted, initial findings suggest that the Alpha and Beta variants present higher rates of severe infection and mortality than the original strain of COVID-19, and the Delta variant is even worse in this regard [4] . A Canadian research report has suggested that an increase in mortality and a shortage of intensive care units may occur nationwide due to the prevalence of the Delta variant. Therefore, wearing masks and social distancing in unvaccinated risk groups as NPIs should be more rigorously implemented, along with preparing ICU beds.

Fifth, variants cause re-infection and breakthrough infections, which occur even after natural infection and vaccination. However, the hospitalization rate and mortality rate are reduced in patients who experience COVID-19 breakthrough infections. Since antibody titers can decrease from 6 months after vaccination, high-risk individuals who received the initial vaccination should take measures against re-infection in the fall. In other words, long-term care facilities that implemented early vaccination initiatives should consider revaccination, while simultaneously blocking the spread of the Delta variant by expanding monitoring and limiting visits.

Sixth, if vaccination uptake increases, the number of patients will naturally decrease. Nonetheless, even if the alert level is downgraded, there is a very high possibility of cluster outbreaks at mass gatherings, such as sports games and events. However, essential businesses and those related to normal life should create a couple of alternatives of ICT centered on rapid testing, contact tracing, and isolation rather than social distancing and movement restrictions.

Finally, international cooperation for securing vaccines is important. Ultimately, vaccinations must be carried out worldwide as a joint effort to prevent the emerging variants and cross-border transmission. The contribution of Korean industry to the scaled-up capability of vaccine production is important, and vaccine aid for low-and middle-income countries with extensive travel to and from Korea is also necessary.

In response to COVID-19, individual liberty and human rights, economic losses, and the strictness of infection control must depend on vaccine uptake, the intensity of COVID-19 spread in the community, and the participation of the public. Political and policy considerations in decisionmaking are very difficult choices. Such decision-making is an art that requires an evidence-based scientific approach, including precise monitoring and surveillance, as well as simulations and modeling.

Not applicable.

The author has no conflicts of interest to declare.

None.

Our World in Data. Coronavirus (COVID-19) vaccinations

Delta variant: what we know about the science

Ministry of Health and Welfare. Coronavirus disease-19, Republic of Korea

Progressive increase in virulence of novel SARS-CoV-2 variants in Ontario

How to deal with the Delta variant this fall