LETTERS: Mutations can make a virus more or less virulent, with a common assumption that virulence will only change if it increases the transmission rate of the virus, which effectively means an increase in the number of virus "offspring".
Mutations are bound to happen when the virus changes its host, for instance, when it spreads out from an animal host to humans or takes advantage of an alternate arthropod vector for transmission.
According to scientists, mutations at amino acid 30 in the Gag protein of human immunodeficiency virus-1 have been proposed as adaptations for the simian immunodeficiency virus ancestors in chimpanzees to increase infectivity in humans.
In the Chikungunya virus, a single mutation (E1-A226V) appearing during epidemics has been suggested as a signature of adaptation to an alternate mosquito vector, Aedes albopictus, while a single mutation (GP-A82V) in the Ebola virus increased the infection of human cells.
Some scientists caution that while there are many examples of mutations that alter virulence or cause drug resistance, hence impacting human health, speculating about the phenotype (observable traits) of any new mutation can be dangerous during fast-moving outbreaks.
One should take these into account when coming to terms with the emergence of the Omicron variant, which requires us to be calm and not panicky and yet be cautious and alert.
It's good that Health Minister Khairy Jamaluddin has cautioned the public not to panic as preventive steps and standard operating procedures (SOP) in Malaysia are stringent.
The ministry is also increasing its genomic surveillance capacity to detect Omicron.
In the meantime, what can be done to come to terms with the Omicron variant pending more accurate information on transmissibility, disease severity and current vaccine effectiveness, is to go back to basics.
They include enhancing public health preventive measures such as wearing face masks, maintaning personal hygiene and physical distancing; speeding up vaccination and intensifying booster jabs for the fully vaccinated.
No matter how menacing a mutated strain is, if it is deprived of its human hosts through public health measures aimed at curbing its transmission, there is not much damage a mutated strain can do.
It's like you are giving zero opportunity for a top-notch criminal to find his victims. Being deprived of human hosts for quite some time, hopefully, the mutated strain becomes dormant.
As for full vaccination, even if it fails to prevent infection, it is usually mild and does not result in severe illness.
The point is, whatever strain, even a virulent one that is attacking you, you will be relatively in a much better position with the high immunity that a double vaccination gives you compared with a low (one dose) or no immunity (nil vaccination) at all.
Thus far, most Covid-19 vaccines have been effective in preventing severe Covid-19, hospitalisation and death, for all previous variants, despite their waning immunity over time.
In fact, this waning immunity can be restored to high immunity with a booster jab.
The immunity provided by the two primary doses begins to wane over time because the antibodies produced after the vaccination to protect the body against the virus naturally decrease over time.
But antibodies are not the body's only defence against the virus. There are certain immune cells, for example the T-cells, that prepare the body to fight off pathogens. And those may not be waning.
Existing public health preventive measures (wearing face masks, physical distancing, avoidance of enclosed spaces, outdoor preference and hand hygiene) that have remained effective against past variants should be observed and remain just as effective in meeting the challenges against Omicron. - Jamari Mohtar. NST (December 14, 2021)
The writer is the Editor of Let's Talk!, an e-newsletter on current affairs. To subscribe copies contact https://www.letstalk.com.my/
