Originally called the Indian variant or B.1.671.2, the Delta variant surged through India, causing a huge spike in infections and deaths earlier this year. — AP
All viruses mutate all the time, especially when they are replicating in a host body.
Therefore, the more people get infected by a certain virus, the more opportunities the virus has to mutate.
In a certain patient infected with Covid-19, for example, the longer the virus remains in the human body, the longer time it has to adapt to the human being’s immune or antibody response.
Many of the viruses will be defeated by the immune response.
But, some will survive and adapt.
These adaptors will replicate and give rise to a new variant, which will survive the human’s immune response.
The South African variant actually came from a South African woman who had HIV, which was not controlled well. It had caused suppression to her immune system.
When she got Covid-19 on top of her HIV, the SARS-CoV-2 virus that causes Covid-19 survived in her body for more than 200 days.
Not at all.
It is but one way for a variant to arise.
If you are immunosuppressed in other ways, such as if you are on cancer drugs or are taking certain drugs to suppress your immune system because you have had an organ transplant or autoimmune disease (such as systemic lupus erythematosus or SLE), you can also give rise to a variant if Covid-19 infects you.
Probably thousands.
But not all of them are of concern.
A Variant of Concern (VOC) is one defined when there is:
- increased transmission rate
- more severe disease. This is defined by worse complications of the disease or increased hospitalisation.
- significantly less impact from antibodies, either garnered from previous Covid-19 infection or vaccination
- reduced treatment or vaccine effectiveness
- inability to detect the variant by usual diagnostic measures.
The VOCs are now given Greek alphabet names rather than the name of country they originated from. This is to avoid marginalisation of certain people from that country or ethnic groups.
This is a good thing to prevent hate crimes, if you ask me.
They are:
- The Alpha variant:
- Originally called the UK variant and also known as B.1.1.7, it has a 50% higher transmission rate, increased hospitalisation and death rates.
- But it seems to be susceptible to Emergency Use Authorisation (EUA) monoclonal antibody treatments and serum.
- The Beta variant:
- Originally called the South African variant, as in the story above and also known as B.1.351, it has a 50% higher transmission rate.
- However, unlike the Alpha variant, it is much less susceptible to EUA monoclonal antibody treatments and serum.
- The Gamma variant:
- Originally called the Brazilian/Japan variant or P1, it is much less susceptible to certain monoclonal antibody treatments and serum.
- The Delta variant:
- Originally called the Indian variant or B.1.671.2, it surged through India, causing the huge spike in infections earlier this year. It has a highly increased transmission rate.
- Apparently, even “fleeting contact” with a Covid-19 patient can infect you. The viral load, once infected, can be as much as 1,000 times higher than from the original Covid-19 virus.
- It appears to be more lethal to people of all ages. Risk of death is twice as high.
- It is the dominant variant in the world right now.
- Like the Beta variant, it is potentially less susceptible to EUA monoclonal antibody treatments and serum.
So far, data from Pfizer Bio-N-Tech, Astra Zeneca-Oxford and Moderna vaccines indicate that they do well against the Delta variant.
Two doses of the Pfizer Bio-N-Tech vaccine render 80% prevention against the Delta variant, 88% effectiveness against symptomatic disease caused by the Delta variant, and 96% against hospitalisation.
This is according to a Public Health England study.
A third dose may be indicated to boost immunity, but results have not been published at this stage.
As for the Moderna vaccine, a Canadian study indicates it is 72% effective against the Delta variant. But it has not been peer-reviewed yet at time of writing.
The Astra Zeneca vaccine has been found to have over 90% effectiveness against the Delta variant as well, in the same Public Health England study.
Dr YLM graduated as a medical doctor, and has been writing for many years on various subjects such as medicine, health, computers and entertainment. For further information, email starhealth@thestar.com.my. The information contained in this column is for general educational purposes only. Neither The Star nor the author gives any warranty on accuracy, completeness, functionality, usefulness or other assurances as to such information. The Star and the author disclaim all responsibility for any losses, damage to property or personal injury suffered directly or indirectly from reliance on such information.
