Relaxation of mask mandates, social distancing norms, and unrestricted travel can contribute to increased transmission; the importance of sustained health research and adherence to the International Health Regulations (IHR) of the WHO cannot be overstated Maharashtra reported 86 new COVID-19 cases on Tuesday, bringing the total number of infections since January 1 to 959, according to the state health department. Nationally, India recorded nearly 300 new cases in the past 24 hours, with Kerala and Maharashtra leading in new infections. The Union Health Ministry currently reports 4302 active cases across the country.
Globally, the situation is also escalating. Although the World Health Organisation (WHO) is no longer tracking worldwide daily case counts, countries like Thailand and Singapore have reported alarming spikes — 47,000 and 54,000 cases, respectively. Meanwhile, the United States and China are no longer reporting figures to the WHO, though anecdotal reports suggest rising case numbers in both countries. The ongoing surge has been attributed to four major SARS-CoV-2 variants: LF.7, XFG, JN.1, and NB.1.8.1. These sublineages emerged from mutations at critical sites of the virus’s spike protein — specifically at amino acid positions 484, 501, 417, and 452, and near the furin cleavage site — which have altered the virus’s behavior, increasing transmissibility and enabling immune evasion.
Generally, surges in COVID-19 cases caused by Omicron or similar variants can result from several factors. Mutations, new sublineages Mutations can lead to new sublineages that more effectively evade existing immunity. This process is primarily driven by changes in the virus’s spike (S) protein, especially within the receptor-binding domain (RBD) and other functional regions. Higher replication rates within an infected individual increase the number of viral copies, providing more opportunities for errors or mutations during RNA synthesis. These mutations can affect the virus’s transmissibility, immune evasion capabilities, and pathogenicity. Mechanism of mutation The virus continuously accumulates mutations during replication. Some of these mutations provide advantages, such as increased transmissibility or the ability to evade immune responses. Selection pressure — where a host’s immune system (natural or vaccine-induced) favors the survival of mutants — plays a key role. Additionally, recombination and convergent evolution allow different viral lineages to independently acquire similar mutations.
No fixed duration Immunity to RNA viruses does not have a fixed duration; it varies depending on the virus and individual factors. Typically, protective immunity can last from several months to a few years. However, for some RNA viruses, immunity may wane more quickly, increasing the likelihood of reinfection upon subsequent exposure. Over time, immunity gained through prior infection or vaccination may decline, raising susceptibility to circulating variants like Omicron. The duration of immunity varies widely. For example, measles typically confers lifelong immunity, while seasonal influenza requires annual vaccinations. Coronaviruses that cause the common cold offer immunity lasting from a few months to a couple of years. For SARS-CoV-2, studies suggest that immunity lasts at least 6 to 8 months post-infection or vaccination, but this protection may decrease over time hence the need for booster doses.
Reduced health measures Relaxation of mask mandates, social distancing norms, and unrestricted travel can contribute to increased transmission. The importance of sustained health research and adherence to the International Health Regulations (IHR) of the WHO cannot be overstated. Recent geopolitical distractions, such as trade and tariff conflicts, have diverted global attention away from urgent health and climate issues. As a result, several hard-won public health gains of the past five decades are slipping from the control of regulatory bodies. Pandemic preparedness agreements aimed at strengthening the IHR and WHO’s authority are essential to regain lost momentum in global health. However, budget cuts in biomedical and vaccine research have forced many seasoned global health experts out of the field. Vaccine coverage gaps: Regions with vaccination coverage below 60 per cent, or those facing uneven distribution, are more vulnerable to surges. Gaps in vaccine coverage are especially concerning among newborns and the elderly — both highly susceptible to COVID-19. India adds 23 million newborns and 13 million senior citizens (>60 years) annually to its population, making it home to the world’s largest elderly population.
Why is COVID-19 spreading?Viral mutations: Certain mutations, especially in the spike protein, can enhance the virus’s ability to bind to human cells, making it more transmissible. Variants such as Delta and Omicron carry multiple mutations that improve their ability to spread. Local crowding: Densely populated areas and crowded environments — such as public transport, marketplaces, and events — increase the number of close contacts per person. Poor ventilation and confined indoor spaces exacerbate airborne transmission. Behavioral factors, including reduced mask use and relaxed social distancing, further heighten the risk.
Seasonal factors Winter and the monsoon, create favorable conditions for viral transmission. What must be done. While molecular surveillance has resumed in high-case areas, national programmes must be strengthened. This includes: Upgrading diagnostic tests to improve sensitivity Developing updated vaccines targeting emerging variants Planning booster campaigns to combat waning immunity Reinforcing public health measures, including masking, hygiene, avoiding crowded spaces Improving indoor ventilation and reducing crowding in shared environments.