India on COVID-19 watch as new variants detected in Gujarat and Tamil Nadu trigger state-level alerts

India’s public health authorities have issued fresh alerts following a measurable increase in COVID-19 cases across Kerala, Maharashtra, Tamil Nadu, Delhi, and Gujarat in the final week of May 2025. Genomic surveillance data reviewed by the Indian SARS-CoV-2 Genomics Consortium (INSACOG) confirmed the emergence of two evolving SARS-CoV-2 sublineages—NB.1.8.1 and LF.7—detected primarily in samples collected from Gujarat and Tamil Nadu.

According to officials from the Union Ministry of Health and Family Welfare, the variants have been placed under active monitoring, and state health departments have been instructed to ramp up real-time genomic sequencing and syndromic surveillance. At present, no link has been established between the new subvariants and any spike in hospitalizations or mortality.

Senior officials at INSACOG stated that preliminary analyses suggest NB.1.8.1 is derived from the BA.2 lineage, with additional spike protein mutations that may support faster community transmission. LF.7, meanwhile, appears to be a sublineage of the XBB variant, carrying unique substitutions associated with partial immune escape, although clinical severity remains low based on current datasets.

Which Indian States Are Reporting a Rise in COVID-19 Cases?

Kerala’s health department has reported localized outbreaks in Thiruvananthapuram and Ernakulam, with daily case numbers rising steadily over the past ten days. Health officers have noted increased demand for RT-PCR testing in government hospitals, prompting reinstatement of triage protocols and active case finding through ward-level health workers.

In Maharashtra, civic authorities in Mumbai and Pune recorded a week-over-week increase in symptomatic cases, though test positivity remains below 3%. The state’s COVID-19 task force, reconstituted earlier this year, has advised precautionary hospital preparedness without announcing any new public restrictions.

Tamil Nadu has launched aggressive contact tracing in Chennai and Coimbatore following the detection of LF.7 variant in community samples. The Directorate of Public Health confirmed that additional samples are being processed at the King Institute and the National Institute of Virology for confirmation and evolutionary mapping.

Delhi’s municipal bodies have issued updated advisories to private hospitals and educational institutions after sporadic clusters were recorded in South Delhi schools. While daily case numbers remain modest, officials are reviewing containment microzones around impacted wards.

Gujarat reported the NB.1.8.1 variant in patient samples from Rajkot and Ahmedabad. State officials have implemented surveillance drives in public transport hubs and advised citizens to wear masks voluntarily in closed or high-footfall spaces.

What Has the Health Ministry Advised for States?

The Ministry of Health and Family Welfare has issued an advisory dated May 24, 2025, directing all states to activate district-level surveillance teams under the Integrated Disease Surveillance Programme (IDSP). Guidelines emphasize early detection through symptomatic screening in high-risk clusters such as nursing homes, government schools, and border transit zones.

The advisory includes specific instructions to maintain genome sequencing of at least 5% of all COVID-positive samples through the INSACOG network. States have been asked to submit daily case data, genomic sequencing reports, and hospitalization trends to the central repository.

While there is no mandate for compulsory masking or travel curbs at this stage, several municipal bodies in Kerala, Tamil Nadu, and Maharashtra have issued city-specific advisories encouraging mask usage in public transport, hospitals, and indoor gatherings.

According to the National Centre for Disease Control (NCDC), genome analysis continues to indicate a predominance of Omicron sublineages, with no significant presence of Delta-era mutations. However, mutations noted in the NB.1.8.1 and LF.7 sublineages are being assessed for neutralization resistance in coordination with international agencies.

What Are the Risks Associated With the NB.1.8.1 and LF.7 Variants?

Virologists from INSACOG and the National Institute of Virology confirmed that NB.1.8.1 carries an S486P mutation in the spike protein, which may enhance ACE2 receptor binding efficiency—potentially increasing its infectiousness. LF.7, meanwhile, has deletions near the N-terminal domain and additional substitutions in the receptor-binding domain that may allow partial immune evasion.

Officials caution that while both variants remain under the “Variants Under Monitoring” (VUM) category, continued mutation-driven evolution could shift them to “Variants of Interest” (VOI) status depending on community spread dynamics and immune impact. Public health agencies have requested labs to fast-track antibody neutralization studies on LF.7 using sera from both vaccinated and previously infected individuals.

Despite the mutations, INSACOG has emphasized that current vaccines, particularly mRNA boosters and protein subunit platforms, are expected to retain effectiveness against severe disease. No data so far suggests a deviation from the clinical patterns seen during previous Omicron-led waves.

How Prepared Is India’s Healthcare Infrastructure for a Renewed COVID-19 Wave?

State health departments across affected regions have reactivated their COVID-19 rapid response teams (RRTs), updated hospital-level COVID beds, and ensured backup oxygen supply availability. The Central Drugs Standard Control Organization (CDSCO) has advised pharmaceutical distributors to review stock levels of molnupiravir, Paxlovid, and remdesivir.

The Indian Council of Medical Research (ICMR) has published a rapid assessment checklist to evaluate district hospital preparedness for any surge in moderate-to-severe cases. The checklist includes availability of high-flow nasal cannulas (HFNCs), non-invasive ventilators, and dedicated infectious disease wards.

Digital infrastructure from the pandemic’s earlier waves—such as the CoWIN platform and Aarogya Setu surveillance backend—is being partially reactivated in hotspot zones for digital contact tracing and symptom reporting.

Medical colleges in Gujarat, Tamil Nadu, and Kerala have been asked to submit clinical data from COVID-positive patients to facilitate real-world effectiveness studies of new variant lineages and associated illness severity.

What Public Messaging and Community Response Measures Are Underway?

Public health campaigns emphasizing precautionary behavior have resumed in urban centers like Mumbai, Chennai, Kochi, and Ahmedabad. Government-run radio and television channels are airing advisories focused on mask discipline, voluntary testing, and booster dose encouragement.

Vaccination booths offering free boosters for vulnerable groups—including elderly citizens, diabetics, and patients with chronic respiratory illnesses—have been reopened in high-density wards in Thiruvananthapuram, Chennai, and South Mumbai.

So far, there has been no panic-driven response from the public or overloading of testing labs. However, local officials continue to monitor pharmacy sales of over-the-counter fever and cold medications to pre-empt unreported community-level outbreaks.

What Comes Next in India’s COVID-19 Management?

While the national caseload remains well below thresholds for concern, the evolving variant landscape is being treated with caution. State and central health authorities continue to emphasize that this is not a wave but a localized spike with potential implications for containment strategies.

The Ministry of Health has not announced plans for renewed lockdowns, school closures, or inter-state mobility restrictions. However, it will conduct a status review in the first week of June based on real-time sequencing and case severity metrics.

India’s genomic surveillance network, strengthened since the second wave, is likely to play a central role in preventing any large-scale resurgence. As officials track NB.1.8.1 and LF.7, they are also looking to coordinate variant data with global partners to contribute to WHO’s global variant monitoring protocols.