The number of deaths from the coronavirus disease (Covid-19) in India exceeded 50,000 on Saturday, making it the fourth country — after the United States, Brazil and Mexico — to cross this bleak milestone as infections mount world over.

However, India’s case fatality rate (CFR) — the proportion of deaths to the total recorded infections — at 1.9%is lower than the global average of 3.5%, indicating that the country has controlled deaths better than other nations with similar or higher caseload.

India is ranked third in the number of infections — only the US and Brazil have recorded more cases than India and have substantially higher death tolls from the viral illness.

As of Saturday, India recorded a cumulative 2,587,872 cases and 50,079 deaths.

The US saw 171,999 deaths from over 5.4 million cases, (CFR of 3.1%) and Brazil 106,608 fatalities from over 3.2 million infections (CFR of 3.2%).

Mexico appears to be among the hardest-hit by the pandemic in the number of deaths, with an exceptionally high death rate, or CFR, of 11%. The country has 55,908 fatalities from just over 511,000 Covid-19 cases.

India also took longer than the three countries in recording its 50,000th fatality: 156 days after reporting its first fatality linked to Covid-19 on March 12.

In comparison, the US — the country worst affected by the public health crisis — took 23 days to breach this mark, Brazil 95 days and Mexico 141 days, according to data by worldometers.info.

India, in the early stages of the outbreak, enforced a 68-day nationwide lockdown starting March 25, when the country had around 602 confirmed cases and 12 deaths. Most curbs have slowly been relaxed in the months since, with the government announcing a phased “unlock” plan from June.

“We do not know yet what the reasons are for fewer deaths in India. However, there are some educated guesses. One, India has a relatively young population... Two, Indians get common cold from other coronaviruses that might be providing cross immunity against Sars-CoV-2,” said Dr Sanjay K Rai, professor of community medicine at the All India Institute of Medical Sciences.

A study published in journal Nature on July 15 hinted that previous exposure to other coronaviruses — such as the one causing common cold — may boost a patient’s immunity to Sars-CoV-2 that causes Covid-19.

“Third, now there is evidence emerging that BCG [Bacille Calmette-Guerin] vaccination given to prevent tuberculosis is protective against Covid-19. We [India] have universal BCG vaccination...” he added.

Although India’s death rate has been lower than other nations, public health experts have cautioned that the toll has been on a steady rise with the increase in daily new infections across states.

In the seven days to August 14, India added an average of 934 deaths daily — about 34% hike from the average 615 fatalities added in the week ending July 19.

This steady rise in the death toll is in line with the trajectory of the epidemic in the country. The virus first found a foothold in India in metropolises such as Delhi and Mumbai — which scaled up testing and other precautionary efforts in response — it has in recent weeks spread to rural areas as restrictions on movement gradually eased, and workplaces and businesses reopened.

While Maharashtra, Tamil Nadu, Karnataka and Delhi were the initial epicentres of the disease, states such as Andhra Pradesh, Bihar, West Bengal, and Uttar Pradesh are emerging as new hot spots, adding thousands of Covid-19 cases daily. These eight states account for over 74.8% of the country’s total tally.

Scientists believe that until a vaccine is developed, retaining a low death rate while focusing on boosting health care infrastructure and widespread testing remain crucial to controlling the disease’s impact in the country.

“A vaccine will help in preventing deaths in high-risk individuals. This infection is unlikely to just disappear... unlike other pandemics, Covid-19 is highly infectious and the spread is truly global... And if re-infection starts happening then we will need to immunise everyone,” said Dr Chandrakant Lahariya, a Delhi-based public health specialist.