COVID-19 is on the rise again in India. Can vaccines stop it? | Science

By Vaishnavi ChandrashekharMar 26, 2021 at 4:50 PM

ScienceCOVID-19 reports are supported by the Heising-Simons Foundation.

Bombay—Just over a month ago, many Indians believed the pandemic was calming down. COVID-19 cases had declined steadily and dramatically for 5 consecutive months, travel restrictions had been lifted, and wedding season was in full swing. In Mumbai, local commuter trains were fully back into service on February 1.

But now a second wave is hitting. Nationwide, cases have risen from just over 11,000 a day in mid-February to over 50,000 a day this week, with more than half in the state of Maharashtra, of which Mumbai is the capital city. The rest are concentrated in five other states, but scientists fear the disease will reappear across the country soon. India is fighting the rise with new restrictions and efforts to scale up vaccination. But although the country is producing two licensed COVID-19 vaccines, its vaccination campaign has yet to gain momentum.

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Coming after the first giant wave of cases in India, which peaked in September 2020, the dramatic decline has defied dire predictions. Antibody surveys, which suggested densely populated areas of cities such as Delhi and Mumbai were close to herd immunity, raised hopes that transmission was running out. (Other Asian countries have also performed relatively well, which has led some to speculate that their populations are somehow less vulnerable to COVID-19.)

But the optimism was perhaps unfounded; a more recent survey of 700 districts found that only about 22% of Indians had been exposed overall. Meanwhile, controls such as masking have been relaxed, travel and social gatherings have increased, and testing and contact tracing has stumbled. “We have let our guard down too quickly,” says virologist Shahid Jameel, director of the Trivedi School of Biosciences at Ashoka University.

Mutations can also revive the pandemic. About 736 of the more than 10,000 samples sent for genomic sequencing in recent months have tested positive for B.1.1.7, a variant first discovered in the UK and known to be more infectious. In Punjab, it was detected in 81% of the 400 samples sequenced. Scientists are also studying a variant with two mutations, E484Q and L452R, found in some districts that are experiencing an exceptional increase in cases. Both mutations are associated with “immune leakage,” or an ability to evade antibodies, and increased infectivity, health ministry officials said this week, although there was no evidence yet. that this variant is at the origin of the thrust.

The climate could also play a role. Some scientists claim that the Indian epidemic may have a seasonal pattern opposite to that seen in Europe and the United States, where winter pushes people indoors, where the virus easily spreads. In India, the summer heat can lead people to retreat to fans and air conditioners in their homes, says Prabhat Jha, epidemiologist and director of the Center for Global Health Research, co-sponsored by St. Michael’s Hospital and the University of Toronto.

Meanwhile, less than 5% of India’s 1.3 billion people have received at least one dose of the vaccine. The AstraZeneca vaccine, manufactured by the Serum Institute of India, accounts for most of the 55 million vaccines issued to date. The other locally produced vaccine, Covaxin, was developed by Bharat Biotech in collaboration with the Indian Council for Medical Research. Both vaccines require two doses.

The government is working to ramp up the pace, currently around 2-3 million shots per day. “My magic number is 10 million doses per day, to cover 300 million in the shortest possible time,” explains epidemiologist Giridhar Babu of the Public Health Foundation of India. This week, the government announced that anyone over the age of 45 can be vaccinated starting April 1.

Officials said vaccine supply would not be a problem, but Reuters reported on Wednesday that India had suspended exports of the AstraZeneca vaccine to help meet domestic demand. India has exported 60 million doses to some 80 countries since January, thanks to bilateral aid – called “vaccine diplomacy” in the national media – commercial contracts, and the Ease of global access to COVID-19 vaccines, a global program to improve access to the vaccine. Earlier this month, the Serum Institute of India, one of the world’s largest vaccine manufacturers, warned that raw material shortages, in part due to temporary restrictions on U.S. exports, could affect its vaccine supply .

We were lucky compared to what could have been. But the story is not over yet. The virus never ceases to surprise us.

As the middle and upper classes flock to get vaccinated, fewer poor people have come. Social workers attribute this to a combination of low awareness and the inability of day workers to take time off. In Mumbai, authorities have started setting up vaccination camps in the slums. It also requires, according to Arun Kumar, director of Apnalaya, a non-profit organization that works in the city’s slums, “massive community programs to allay vaccine fears.”

Some of the fears stem from the hasty approval of Covaxin in early January, before data from the Phase 3 trials became available. “It created doubt,” said former Federal Health Secretary K Sujatha Rao. “Once trust is broken, it is not easy to regain.” On March 3, Bharat Biotech announced that the vaccine was 81% effective, based on an initial, as yet unpublished analysis of 43 cases. The company plans to do another interim analysis after 87 cases, and a final after 130 cases.

Reports of informed consent violations in trials and insufficient transparency regarding adverse events may also have shaken confidence. On March 16, a group of 29 doctors and researchers wrote a letter about reported vaccine deaths – 80 so far since the vaccination campaign began in January. While the vaccines may not have caused death, the petitioners say, the government should investigate them and disclose the results. Unlike at least 20 European countries, India has not halted use of the AstraZeneca vaccine after reporting serious bleeding disorders, but officials said they were reviewing the data.

In an attempt to slow the second wave, several states and cities have reintroduced restrictions on social gatherings, imposed temporary lockdowns, and stepped up testing and tracing. In Mumbai, once again a pandemic hotspot, the city has banned public Holi Spring Festival celebrations this coming weekend. The state of Uttarakhand, however, removed restrictions on the Mahakumbh, a religious congregation that met every 12 years, allowing some 3 million people to gather on the first day of the festival, March 11. Some of those restrictions were reinstated this week.

“We were lucky compared to what could have been,” says Babu. “But the story is not over yet. The virus never ceases to surprise us.