Covid-19: Highly transmissible JN.1 strain now in Malaysia

 

There may be more than holiday cheer being spread this festive season as the highly contagious Covid-19 strain JN.1 marked its entry into Malaysia yesterday.

Sixty-one samples collected in several parts of Sarawak on Dec 21 detected two dominant Omicron sub-variants - the JN.1 (49 percent) and HK.3 (26 percent).

“These samples were primarily identified in the Kuching/Samarahan areas, with a few cases in Sibu,” said the director of the Institute of Health and Community Medicine, Universiti Malaysia Sarawak, Dr David Perera.

The World Health Organization on Dec 19 classified JN.1 as a Covid-19 variant of interest following its “rapidly increasing spread” around the globe.

According to virologist Dr Lam Sai Kit, the rapid spread of JN.1 in the last few months suggests its high transmissibility.

“It is probably better at evading our immune systems. JN.1 contains an additional mutation that affects the virus spike proteins which is essential for entry into host cells,” he told Bernama when contacted.

There has yet to be evidence that JN.1 poses an increased risk to public health relative to other circulating variants, he said.

However, it also does not mean that it presents less of a threat to those with poorer health.

“The primary symptoms of JN.1 infection are similar to those caused by other circulating variants of the Omicron lineage.

“In elderly patients, the immunocompromised and those with debilitating diseases such as diabetes and heart diseases, sub-variants such as JN.1 can result in hospitalisation and death.

“Even in young healthy individuals, it may result in long Covid,” said Lam.

JN.1 was first detected in September in the US. By Dec 8, it made up about 15 to 29 percent of Covid-19 cases, according to the US Centers for Disease Control and Prevention.

Over 40 countries have already reported JN.1 including the UK, Denmark, Spain and Iceland.

Last week, China detected seven infections of JN.1 while India has just detected JN.1 by RT-PCR in its ongoing surveillance. Singapore, Thailand, Indonesia and Australia have also reported JN.1 in their respective countries.

The best defence remains getting vaccinated, masking up in crowded areas and limiting exposure to people who have been infected, said Lam.

“The good news is that there are positive indications that existing vaccines, especially the bivalent and the updated monovalent vaccines, will generate antibodies that work against JN.1 and other currently circulating sub-variants.

“These antibodies may not totally block transmission or infections but should reduce the likelihood of severe disease and death,” he said.

However, Lam added, vaccinations are still necessary.

“The unvaccinated and uninfected people are ideal hosts for Covid-19 and in generating new variants due to the absence of negative selection by antibodies, which makes it easier for the virus to replicate and produce new mutations,” he said.

Covid-19 would continue to mutate due to selection pressure, making it important for countries to continue monitoring antigenic changes and sharing the information with the rest of the world.

“JN.1 will not be the last sub-variant of the Omicron lineage,” stressed Lam.

- Bernama