Covid-19 spike in Asia: How dangerous is JN.1 variant and should India be worried | Key points

With COVID-19 cases on the rise across parts of Asia, particularly in densely populated Singapore, Hong Kong, China and Thailand, the attention has turned towards what is said to be the new driver behind the surge: the JN.1 variant, which is a subvariant of the Omicron lineage.

Along with its closely related descendants, JN.1 has rapidly become one of the most prevalent strains in circulation globally.

Singapore has raised its alert levels as Covid-19 cases continue to climb, with an estimated 14,200 infections reported in the week ending May 3 - up from 11,100 the previous week. Daily hospitalisations have also jumped by around 30%, prompting concern among health authorities.

In Hong Kong, officials have warned that the virus has reached a “quite high” level. Albert Au, head of the Communicable Disease Branch at the Centre for Health Protection, noted that the positivity rate in respiratory samples is now the highest in a year. The week ending May 3 saw 31 Covid-related deaths - also the highest weekly toll in a year - alongside a surge in severe cases.

What is the JN.1 variant?

JN.1 is a sublineage of the Omicron variant, specifically descending from the BA.2.86 (Pirola) strain, which itself was known for having an unusually high number of mutations. First identified in late 2023, JN.1 quickly gained traction in several countries, including the United States, the UK, India, Singapore, and Hong Kong.

What sets JN.1 apart is a unique mutation in the spike protein — the part of the virus that binds to human cells. This mutation may give the virus an edge in terms of transmissibility and immune escape, meaning it could spread more easily and potentially evade antibodies generated by vaccines or past infections.

According to the World Health Organization (WHO), JN.1 has been designated a "variant of interest", though not yet a "variant of concern." That suggests close monitoring is underway but there's no conclusive evidence (yet) that it causes more severe illness than other Omicron subvariants.

How dangerous is JN.1?

So far, JN.1 does not appear to cause more severe disease than earlier Omicron strains. Most infections have been reported as mild to moderate, with symptoms similar to past Omicron infections: sore throat, runny nose, fatigue, cough, and fever. However, its high transmissibility is what makes it concerning.

While hospitalization rates have not dramatically spiked, older adults, the immunocompromised, and those with chronic health conditions remain vulnerable to complications.

In Singapore, health authorities have attributed the recent spike in Covid-19 infections to the LF.7 and NB.1.8 variants — both offshoots of the JN.1 sub-lineage of the Omicron strain.

Together, these two variants account for roughly two-thirds of the locally sequenced cases. Officials also suggested that the surge may be driven by waning immunity within the population.

The symptoms of these variants closely resemble those of other Covid-19 strains. Common signs include sore throat, fever, dry cough, fatigue, nasal congestion or a runny nose, headache, muscle aches, and loss of taste or smell. Some individuals may also experience conjunctivitis, diarrhoea, or mild gastrointestinal discomfort.

Do vaccines work against JN.1?

The short answer: Yes, but with reduced effectiveness.

Studies so far suggest that the updated bivalent and monovalent mRNA vaccines (like those from Pfizer-BioNTech and Moderna) still offer protection against severe illness, hospitalization, and death caused by JN.1, even if they’re less effective at preventing mild or asymptomatic infection.

This is because while JN.1 carries new mutations, its core structure still resembles that of previous Omicron strains — the target of current vaccines. Boosters, especially those updated in 2023–2024 to target newer variants, increase antibody levels that can neutralize JN.1.

Should India worry?

As of May 19, there are 257 active COVID-19 cases in India. This count stood at 93 last Friday.

Doctors in Mumbai have observed a modest rise in mild Covid-19 cases, mostly among younger people. However, there is no sign of a fresh wave. Health authorities continue to urge caution, particularly as neighbouring countries report a surge in infections.

News agency PTI quoted on Monday quoted official sources saying that the current coronavirus situation in the country was under control, even as they are keeping an eye on reports of a rise in Covid cases in Singapore and Hong Kong.

The country has a robust system for surveillance of viral respiratory illnesses, including COVID-19, through the Integrated Disease Surveillance Programme (IDSP) and ICMR. Hospitals have been asked to monitor influenza-like illnesses and severe acute respiratory infection cases.