India versus Omicron: How the country’s third COVID-19 wave might unfold

Images of makeshift crematoriums, bodies washed up on the banks of the Ganges, and tearful relatives pleading for oxygen or hospital beds for their loved ones remain some of the most harrowing of the COVID-19 pandemic. India was hit extremely hard during its second wave of disease, which peaked during May 2021, and the country has experienced one of the world’s highest death tolls overall, with an estimated five million dead. Now, it is bracing itself for a third wave of disease, driven by the highly transmissible Omicron variant.

The good news is that the combination of vaccinations and natural immunity means many Indians are likely to have some degree of T cell immunity to SARS-CoV-2.

The country reported 247,417 new COVID-19 cases on 13 January 2021 – the highest in 236 days, and 27% higher than the day before. Only 620 of these cases were confirmed as Omicron, bringing the overall tally to 5,488, but the true number is likely to be far higher, because confirming someone is infected with the Omicron variant requires a full genetic analysis of that person’s swab, which can take several weeks.

Neither is the daily case rate an accurate reflection of current infections, as people only tend to get tested once they develop symptoms – and not everyone gets tested. When cases are increasing exponentially, as they have been recently, the reported figures are often a poor estimate of the reality.

The daily total has not yet exceeded the roughly 400,000 daily cases India experienced at the height of its second wave – although, based on current trends, daily cases aren’t expected to peak until the second half of January in Jharkhand, eastern India, and until around the end of January in Delhi. So, will things get as bad as during the previous wave?

Better prepared

In many ways, the country is in a better position than it was during the Spring, when the emergence of the Delta variant fuelled a similarly alarming surge in cases. The government has massively increased supplies of medical oxygen and strengthened distribution networks for this lifesaving gas. Doctors are also more experienced at treating those with severe disease.

Then there are COVID-19 vaccines, which India began administering on 16 January 2021 – exactly one year ago – with more than 1.54 billion doses given so far.  As of 30 December, 2021, roughly 64% of India's adult population had been fully vaccinated against COVID-19 and around 90% had received a first dose.

However, vaccination rates vary across the country. In Uttar Pradesh, India’s most populous state, only around a third of adults are fully vaccinated. Nationally, there are still millions of adults who are unvaccinated – many of whom have underlying medical problems such as diabetes, malnutrition or tuberculosis, which could increase the severity of their illness.

On the other hand, many Indians have previously been infected with COVID-19 and recovered. According to a national survey conducted in June and July, an estimated 68% of Indians had antibodies against SARS-CoV-2. Separate surveys in Mumbai in August, and Delhi in October, suggested 87% and 97% of adults had antibodies, respectively – although some of these could be due to vaccination.

Waning immunity

Through this combination of vaccination and natural infection, it is likely that many Indians have at least some immunity to COVID-19, meaning they are at lower risk of severe disease. The question is how much immunity? Antibodies are known to wane over time, and the wave of Delta infections hit India earlier than many other countries, meaning a longer time has elapsed since many people were infected.

India also rightly focused on immunising its frontline workers and most vulnerable individuals first; the downside is that their levels of protective antibodies are likely to have plummeted since then, and the country only began administering booster doses on 10 January.

The Omicron variant is also partially resistant to the immunity conferred by existing vaccines and infection, and it is more transmissible than previous variants of concern, including Delta. Even though it appears to be associated with less severe disease, a rapid increase in cases will result in an increase in hospitalisations, and may overwhelm health systems in some areas.

The good news is that the combination of vaccinations and natural immunity means many Indians are likely to have some degree of T cell immunity to SARS-CoV-2. Whilst this won’t necessarily prevent them from becoming infected and spreading the virus to other people, it could prevent a significant number of them from becoming severely unwell, or dying from the disease. Both South Africa and the UK – the first countries to be hit by the new variant – have experienced far lower rates of hospitalisations than in earlier waves.

However, the problems wrought by high rates of COVID-19 infection aren’t limited to availability of oxygen and hospital beds. Many UK hospitals have declared critical incidents in recent days – meaning they cannot provide priority services such as treatment for cancer or heart disease patients due to staffing shortages and very high demand for care. Rapid access to COVID-19 vaccines and information on how to prevent the spread of COVID-19 have never been more urgent.