UPSC Essentials | One word a day — JN.1, the new COVID-19 sub-variant

Subject: Science, Health

Let’s begin with a MCQ:

Concerning ‘Varient of Interest’ (VOI), seen in the news due to the new Covid-19 sub-variant, consider the following statements:

1. A variant is designated as VOI by WHO if it shows a growth advantage over other circulating variants — meaning its proportion increases along with any increase in the total number of cases.

2. A variant can be designated as VOI if it is predicted to or known to change characteristics such as transmissibility, virulence, antibody evasion, or susceptibility to therapies and diagnostics.

3. Once designated as VOI, the WHO monitors, tracks its global spread and the body also keeps assessing its public health risk and facilitates the sharing of isolates.

Which of the above statement/s is/are correct?

(a) 1 and 2 only

(b) 2 and 3 only

(c)  3 only

(d) 1, 2 and 3

(Check the answer towards the end of the article)

WHY IN NEWS?

— With cases of the Covid-19 sub-variant JN.1 on the rise across several countries, the World Health Organization (WHO) on Tuesday designated it as a “variant of interest” separate from its ancestor BA.2.86 that is commonly referred to as Pirola.

— The Union health ministry has written to states and Union Territories, asking them to monitor cases of influenza-like illnesses, conduct adequate testing, and send all positive samples for whole genome sequencing.

KEY TAKEAWAYS

— The sub-variant JN.1 is a descendant of the BA.2.86 variant, commonly referred to as Pirola, and is not exactly new. The first cases of this variant were detected in the United States in September and the first case globally was detected as early as January this year.

— While JN.1 contains only one additional mutation on the spike protein as compared with Pirola, it has been on the watch-list of researchers because Pirola contains more than 30 mutations on the spike protein.

BTW

— Mutations on the spike protein of Sars-CoV-2 matter because they are the ones that attach to receptors on a human cell and allow the virus to enter it.

Can it lead to a surge, or more severe symptoms?

— There is no evidence to suggest that JN.1 can cause worse symptoms or spread faster than the variants already in circulation.

— Initially, there were concerns that the high number of mutations could mean that Pirola would evade immune response more easily and spread rapidly. That, however, hasn’t happened.

— In fact, an assessment by the WHO Technical Advisory Group on COVID-19 Vaccine Composition showed that Pirola and JN.1 were both effectively neutralised by serum from humans who had had the infection and vaccination.

— While Pirola and JN.1 are considered to be Variants of Interest, they have not been designated as Variants of Concern

What it means to be ‘Varients of Interest’ (VOI) and ‘Varients of Concerns’?

— ‘Varients of Interest’: Variants that are less effectively neutralised in labs by antibodies from infection or vaccination and have a potential to spread.

— A variant is designated as VOI by WHO if it shows a growth advantage over other circulating variants — meaning its proportion increases along with any increase in the total number of cases.

— A variant can be designated as VOI also if it is predicted to or known to change characteristics such as transmissibility, virulence, antibody evasion, or susceptibility to therapies and diagnostics.

— Once designated as VOI, the WHO monitors and tracks its global spread. The body also keeps assessing its public health risk and facilitate sharing of isolates.

— Member states have to report cases of VOI, monitor it, and conduct field investigations to study the potential impact of the variant.

— ‘Varients of Concerns’: Variants that result in increased transmission, severe disease leading to hospitalisation, and reduce effectiveness of vaccines.

What has led to the current concerns?

— There is definitely an increase in the number of cases being caused by Pirola and its close relative JN.1 globally. Cases have been detected in the USA, some European countries, Singapore, and China.

— A statement from WHO said that Pirola and its descendants accounted for 17% of the Sars-CoV-2 sequences uploaded to the global database Global Initiative on Sharing All Influenza Data (GISAID).

— By the beginning of December, more than half of these sequences were that of JN.1. In the United States, JN.1 accounted for 15% to 29% of the circulating Covid-19 variants.

— Singapore has recorded an estimated 56,043 cases during the week of December 4 to 10. It also saw an increase in hospitalisation, mostly among those above the age of 60.

Do you need additional shots?

— While data from Singapore shows that those who had received their last Covid-19 vaccine dose more than a year ago were 1.6 times more likely to need hospitalisation, experts said that a wide coverage of vaccination and subsequent non-symptomatic infections are likely to have resulted in a significant level of protection in India.

How can you protect yourself?

— Experts say that while new variants of Sars-CoV-2 will keep emerging, protective measures against a respiratory virus remain the same. Doctors suggest masking up in crowded areas, especially enclosed ones, if the number of cases is increasing locally.

— Remaining in well-ventilated spaces reduces the spread of the infection. Also, washing hands frequently prevents the infection.

JUST FYI

Is JN.1 more infectious?

‘Increased transmission, immune escape and prolonged infectious period’

Dr Rajesh Karyakarte, genome sequencing coordinator for Maharashtra, says the growth advantage is exponential and cites WHO data that shows how JN.1 rapidly increased from just 3.3 per cent of all coronavirus cases between October 30 and November 5 to 27 per cent a month later. “This is an 86 percent growth advantage,’” says Dr Karyakarte, reasoning that it was due to the increased transmission, immune escape and a prolonged infectious period.

This suggests that it is contagious and is getting better at going past the body’s immunity defence than the ancestral strain, according to the CDC. But the spike transmission doesn’t mean that it causes severe disease as hospital admission is low. Experts also say it is a low risk infection and people with prior infection and/or vaccination need not worry.

Faster spread due to additional mutation in the spike protein

Genome researchers Vinod Scaria and Bani Jolly have said that the SARS-CoV-2 virus is continuously evolving and forming new lineages. “Every infection provides the virus with the possibility to evolve further and JN.1 is an Omicron sub-lineage that is characterised by an additional spike protein mutation, L455S. The high immune escape property would mean that JN.1 could out-compete other variants,” they say.

A recent  study in Lancet found that the one mutation alone gives JN.1 the ability to evade immune response faster than its parent BA.2.86.