WHO shares updates, guidance on new SARS-CoV-2 variants

World Health Organization (WHO) Report, Coronavirus 2019 (COVID-19) pandemic, full of risk assessment and guidance for a series of SARS-CoV-2 mutants recently observed.

The Global Health Agency has highlighted a quartet of variants currently in circulation since various points in the last year.

D614G Substitution Variant – Primary Virus

Currently the predominant form of the global virus is the SARS-CoV-2 mutant with a D614G substitution in the gene encoding the peplomer, late January 2020 or 2 before overwhelming the strains identified in China. First observed in the moon.

In June, infectivity and infection with previous strains increased, making it the predominant strain. However, it does not cause larger illnesses or worsen the effectiveness of existing laboratory diagnostics, treatments, vaccines, or epidemiological efforts.

Danish “cluster 5” variant

SARS-CoV-2 mutants were identified in the North Denmark region of Denmark in August and September. It was then characterized by an association with infection during farmed mink before it was transmitted to humans. Having multiple mutations previously unobserved, experts say it can lead to reduced viral neutralization and reduce the degree and duration of immune protection from infection recovery or vaccination. Raised concern.

A variant of “cluster 5” is currently being evaluated for viral neutralization in infected humans, but only 12 cases were reported in Denmark in September, indicating no widespread infection. Hmm.

UK variant

Three weeks ago, the UK first reported to WHO SARS-CoV-2 variant B117. It has since been observed to have a 23 nucleotide substitution, with no phylogenetic relationship to the virus prevailing in the country.

This variant first appeared in southeast England, but has since replaced viral strains in the region as well as London.

Preliminary evaluations show that although the mutants are more contagious, there is no change in disease severity and no risk of reinfection, depending on length of stay and case fatality rate for 28 days.

Another mutation in this variant appears to affect diagnostic PCR assays using the S gene target, but the effect is not expected to be significant.

As of this week, this variant has been reported in 31 other countries / regions and 5 of the 6 WHO regions.

South Africa 5O1Y.V2 variant

A new variant was detected by South African authorities on 18 December and rapidly spread to three states with the N501Y mutation.

A month ago, routine sequences observed that this variant had largely replaced other SARS-CoV-2 viruses in the Eastern Cape, West Cape, and KwaZulu-Natal regions. Despite this rapid migration and the higher viral load observed that may be contagious, further research is needed.

In addition, WHO has now shown that there is no evidence that this mutation is associated with a more serious disease or worse outcome, but again, more research is needed. As of this week, it has been reported in four other countries.

Response to variant

Authorities in the affected countries are currently conducting epidemiological and virological assessments of these variants, as well as adding genomic data from the UK and South African variants to the Global Initiative for Avian Influenza Information Sharing (GISAID). In addition, WHO emphasized a series of actions initiated to respond to new threats:

• Enhanced sampling in the affected area to interpret the circulation and spread of the new variant.
• Evaluation by the National Scientific Team to observe the effects of mutations on reinfection, vaccination, diagnostic testing, severity of infection, and infectivity.
• In collaboration with WHO and research / government authorities, we will analyze epidemiology, modeling, phylogeny, and laboratory findings as they become available.
• Work with WHO and national authorities to identify means of enhancing the SARS-CoV-2 surveillance system and implement or enhance gene sequencing capabilities to assess variants.
• Improve community involvement and communication to publicly explain the impact of SARS-CoV-2 mutants on public health, with an emphasis on ongoing social distance strategies, while research continues.

Variant risk assessment

WHO has emphasized that the commonality of viruses changes over time, but in many cases there is no direct benefit to their infectivity or infectivity, and in some cases their growth is restricted. They also noted that the risk of viral mutations increases with the frequency of human and animal infections.

“Therefore, reducing SARS-CoV-2 infection and avoiding its introduction into animal populations using established disease management methods is a global way to reduce the incidence of mutations that adversely affect public health. It’s an important aspect of strategy, “they write.

Initial assessments suggest that UK and South African variants do not result in changes in clinical symptoms or severity, but higher case incidence may increase COVID-19-related hospitalizations. , Therefore you may die. As a result, WHO warned that more intensive public health measures may be required to control the transmission of mutants while the study is pending.

guidance

Existing strategies for disease management, including epidemiological surveillance, strategic testing, contact tracing, coordinated public health and social measures, are recommended to continue during the investigation of variants.

WHO also advised countries to increase regular phylogenetic sequencing of SARS-CoV-2 virus, if possible, to better monitor the emergence of mutants.

“Although SARS-CoV-2 mutations are expected, it is important to continue to monitor the public health effects of new viral variants,” they write. “Increased transmission rates associated with SARS-CoV-2 mutants can be more difficult to control.”

In addition, authorities will work with national and regional health agencies in the travel, transportation, and tourism sectors to provide and disseminate information about variants to travelers to and from countries affected by the new variant. I advised to reserve resources to prevent it.

“Countries also need to ensure that measures affecting international transport are risk-based, evidence-based, coherent, proportional, and time-limited,” they wrote. “In all situations, important national travel should always be prioritized and promoted.”