[Anti-epidemic Tips! What is the Delta variant virus?]

I've been hearing a lot about the Delta variant lately, and it seems incredibly promising. What exactly is Delta? Is there a Beta?

According to an article recently written by Dr. Chen Desheng on the website of the Hong Kong Jockey Club Disaster Preparedness and Response Education and Research Centre, the Delta variant of the new coronavirus was first discovered in India, then spread to the UK, and began to spread around the world.

The novel coronavirus has found its new host in humans. Because the human body presents a novel environment for the virus, it is exposed to a variety of threats. To adapt, the virus constantly mutates to increase its chances of survival and reproduction. To enter and reproduce in human cells, the novel coronavirus uses its spike protein (like a key) to unlock the ACE2 receptor (like a door lock) on human cells. To more easily bind to the ACE2 receptor and spread to more people, the novel coronavirus's spike protein continues to mutate. This reduces the effectiveness of the immune system's antibodies against these mutated viruses (also known as variants). Consequently, these variants not only damage the body but also multiply rapidly, increasing the chances of transmission.

The novel coronavirus's spike protein is composed of a string of amino acids. Frequently heard variant code names, such as D614G, N501Y, E484K, and L452R, refer to a mutation in one of the amino acids in the S protein. For example, "N501Y" refers to a variant in which the amino acid at position 501 of the S protein has mutated from "N" to "Y," creating the "N501Y" variant.

However, these codes are not easy for ordinary people to remember, so for convenience, some people named the variant virus after the place where it was first discovered, such as the British variant virus, the South African variant virus, etc. However, the World Health Organization (WHO) believes that the virus should not be stigmatized by a specific country, so it uses Greek letters to name the variant virus instead.

The WHO database contains many variants of the novel coronavirus, codenamed from Alpha, Beta, and Lambda. However, not all variants have a significant impact on humans. Therefore, the WHO has proposed the concept of Variants of Concern (VOC), which uses VOC to define which viruses have a greater impact on humans. Factors considered include: (1) increased infectivity, (2) increased harm to the human body, and (3) reduced immune system protection (including vaccine protection). Currently, the WHO VOC list lists only four variants that have a greater impact on humans, including Alpha, Beta, Gamma, and Delta.

The destructive power of the Delta virus: A UK database shows that the hospitalization rate for those infected with the Delta variant is twice that of the Alpha variant! Fortunately, data shows that the Delta virus only slightly increases its destructive power. Analysis shows that it simply aims to increase its infectiousness to reproduce, rather than killing the host and perishing together, so its destructive power is not extremely high.

Delta virus antibody protection: Many people are concerned about whether vaccines provide adequate protection against infection and harm from variants. Data shows that all vaccines approved for emergency use by the WHO remain effective against variants, particularly in reducing the risk of severe illness. Data from Public Health England shows that one dose of the vaccine offers only a 30% protection rate, but two doses of the Pfizer vaccine offer a 96% protection rate against severe illness and the need for hospitalization, making it crucial to complete both doses.

Source: www.hkjcdpri.org.hk