Covid-19 Resurgence: New Subvariants and Rising Cases in India and Southeast Asia
Across Southeast Asia,Covid-19 cases are once again on the rise,prompting increased vigilance from health officials. India is also experiencing a slow rise in infections, leading Karnataka, delhi, and West Bengal to issue health advisories. Despite the uptick, health officials are urging the public to remain calm and avoid panic.
Emergence of New Subvariants: NB.1.8.1 and LF.7
India’s SARS-CoV-2 Genomics Consortium (INSACOG) has identified two new coronavirus subvariants: NB.1.8.1 and LF.7. these variants are currently under scrutiny to determine their potential impact on public health.
What are NB.1.8.1 and LF.7?
The World Health Association (WHO) has classified both NB.1.8.1 and LF.7 as “Variants Under Monitoring.” This designation means that these variants are being closely tracked but have not yet been labeled as “Variants of Concern” or “Variants of Interest.” According to The Hindu,these subvariants are believed to be contributing to the recent surge in Covid-19 cases in China and other parts of Asia.
INSACOG data indicates that one case of NB.1.8.1 was detected in Tamil Nadu in April, while four cases of LF.7 where found in Gujarat in May. Both subvariants are offshoots of the JN.1 variant, which is known for its rapid spread.
Deep Dive: NB.1.8.1 Variant
NB.1.8.1 is a subvariant derived from a recombinant strain called XDV.1.5.1. The earliest known cases date back to Jan 22, 2025. Compared to the LP8.1 variant, NB.1.8.1 has six mutations in the spike protein, and eight mutations compared to JN.1, according to The Indian Express.
Early research suggests that NB.1.8.1 may have a higher transmission rate than previous variants, potentially due to its stronger binding affinity to human cells. As of now, 58 sequences of NB.1.8.1 have been submitted to the global Covid-19 genome database from 22 countries.
This variant exhibits spike protein mutations (A435S, V445H, T478I) that could enhance its ability to spread quickly and partially evade the body’s immune response. Data from china suggests it is highly transmissible, which may explain its increasing prevalence in certain regions. NB.1.8.1 has been detected through airport screening in the United States (California, Washington, Virginia, and New York), as well as in Japan, South Korea, Thailand, and other countries.
Symptoms Associated with the Subvariants
The symptoms associated with NB.1.8.1 and LF.7 appear to be similar to those observed with earlier omicron strains:
- Fever
- Sore throat
- Loss of appetite
- Tiredness
- Mild cough
- Headache
- Blocked nose
- Nausea
- Stomach-related issues
Current Covid-19 Situation in India
As of recent reports, India has 1,009 active Covid-19 cases. Kerala has the highest number of active cases with 430, adding 335 new infections since May 19. Maharashtra follows with 209 active cases, including 153 reported in the past week, and has recorded four Covid-related deaths. Delhi has added 99 new cases, bringing its total to 104.
Other states reporting infections include:
- West Bengal (12)
- Rajasthan (13)
- Uttar Pradesh (15)
- Tamil Nadu (69)
- Karnataka (47)
- Gujarat (83)
Health officials emphasize that most current cases are mild and are being managed at home.
Recent fatalities include an 84-year-old man with multiple health issues in karnataka, who tested positive for Covid-19 post-mortem, marking the state’s first virus-related death in the recent surge. In Maharashtra, a 21-year-old man with severe diabetes died in a Thane hospital after testing positive. Bihar reported its first Covid-19 case in the ongoing wave, with a 31-year-old man from Patna testing positive, according to PTI.
The Union Health Secretary convened a review meeting with top officials from various health organizations to assess the situation. Officials noted that the JN.1 variant is the predominant strain driving the increase in infections, accounting for approximately 53% of new cases.
Cases have mainly been reported from Kerala, Tamil Nadu, Maharashtra, and Karnataka. most cases are mild and under home care.
The Health Ministry
While the situation is evolving, health departments in affected states are advising peopel to adhere to preventive measures, stay up-to-date with vaccinations, and avoid panic as the country monitors these new variants.