Looking beyond the second wave of Covid

AFTER two months of the devastating second wave, India’s Covid cases seem to be on a downward trend. India saw an unprecedented spike in the daily caseload beginning in March, reaching over four lakh in the first week of May this year with deaths crossing 4,500 on a single day, the highest in the world. The test positivity had also crossed an alarming 25%. The main reasons for the explosion of cases were lowering of the guard on masks and social distancing due to complacency, congregations during election rallies and the emergence of new more transmissible variants of the virus.

India is now witnessing another epidemic, that of mucormycosis. Already approximately 30,000 cases have been reported. Present data suggest that Rhizopus arrhizus is the predominant agent causing Covid-associated mucormycosis (CAM) in India. A majority of (CAM) patients have uncontrolled diabetes. At the PGI, over 200 new CAM cases have been seen so far in 2021, with a majority having Covid while about 15% had recovered from it and some did not have Covid. Apart from the fact that steroids can cause elevation in blood sugar levels, SARS-CoV-2 itself can induce damage to pancreatic islets cells, which have a high expression of ACE-2 receptors. Increased resistance to insulin due to the inflammatory reaction may also be responsible for the elevation of blood sugar. A significant observation is that hardly any patient treated for Covid-19 at the PGI developed mucormycosis. This suggests that indiscriminate and prolonged use of steroids by treating doctors is the key factor. Despite guidelines clearly stating that steroids are recommended for moderate or severe cases only when oxygen levels drop, patients have been receiving steroids in many mild cases.

Apart from the unwarranted use of steroids in many patients, there has been a widespread practice of giving multiple antibiotics, Ivermectin, Hydroxychloroquin and sometimes prophylactic antifungal drugs by physicians. Even convalescent plasma continued to be used despite WHO negating its benefit over six months ago. The clamour for Remdesivir was also much beyond the actual number of patients who might have benefitted from it. These indiscretions caused panic resulting in hoarding and black marketing. People even stockpiled oxygen at home. Many doctors are yet to follow the Ministry of Health and Family Welfare guidelines, either ignoring them or not being aware of them.

One major cause of the destruction caused by the second wave is the emergence of Delta variant. Mutations in the viral genome leading to development of variants can make the virus more transmissible and immune to vaccines or make it cause more severe disease. Duration of infectiousness may also be increased. A recent CSIR-led research on genomic analysis of samples from November 2020 to April 2021 has shown Delta variant to be the dominant strain in India. This strain is 70% more transmissible than the Alpha variant which itself is 50% more transmissible than the original virus. Other research (Lancet June 3) has shown that two doses of Pfizer-BioNtech vaccine had five times less neutralising antibodies against the Delta variant than against other variants. Delta variant has also been thought to cause more severe disease.

It is important for India to increase genomic sequencing so as to be ahead of impending likelihood of resurgence due to more infectious or more deadly strains. Being a large country, we need to sequence samples from different states. The importance of this strategy can be gauged from the fact that after the emergence of Delta variant in the UK, the government has slowed down lifting of the lockdown.

Additionally, there is a need to do serological surveys in different parts of the country. Antibody levels give an estimate of the population which is still vulnerable. Using this data, we can strategise our vaccination delivery better.

There has been speculation that India may have a third wave in a few months. This is based on the emergence of a third wave in some countries like Italy, France and UK after 8 to 23 weeks of the second wave. No one can deny this likelihood till we have adequate herd immunity through natural infection or vaccination. Moreover, there being a probability of new variants which may escape immunity, another wave is very much possible. Some experts believe that it is not a question of ‘if’ but ‘when’. It is also being speculated that the third wave will involve children. The logic behind that is the likely protection of adults through natural infection or vaccination, leaving children vulnerable. However, experience from Europe and the US suggests that children are infrequently affected. Some experts attribute it to the lack of ACE-2 and other receptors in lungs of children. However, with the current rate of vaccination, even large segments of our total population remain susceptible to one or more waves. In any case, we need to ramp up our paediatric healthcare and augment infrastructure, especially oxygen supply which was found wanting earlier.

To limit the damage in coming months after the rampaging second wave, we need to pull all our resources. Foremost of them is vaccination. With the announcement of a new vaccine policy of the government and increased availability of vaccines in coming months, we need to scale up daily vaccinations to 70 lakh a day or more to hope to reach herd immunity in the next six months. That remains our best bet against the next wave. There have been concerns about the adverse effects of vaccines and the chances of re-infection. So far, an insignificant number of serious adverse effects have been reported in India so far. Re-infection or breakthrough infection after two doses of vaccine is also quite low. In a study from PGI on vaccinated healthcare workers who had completed at least two weeks after the second dose, only 1.6% of the 3,000 recipients got re-infected. Among those who were never vaccinated, the number of infections was six times more.

As the lockdown got lifted partially a few days back, we are seeing people flocking to markets and flouting social distancing norms. After a peak of four lakh cases, 80,000-90,000 cases look reassuring but they have the potential to cause a flare-up. We must avoid crowding, social gatherings and unnecessary travel yet. We must continue with the mask and ensure it is worn properly. Since the virus also spreads through aerosols, proper ventilation of buildings must be ensured. This holds true especially for government offices. We must bring back the same seriousness as we had in the initial days of the pandemic, a limited number of clients or customers entering premises and queues being maintained with a distance of two metres. It is too early yet to reopen educational institutions. Lastly, as the second wave had a high attack rate among household members, contact tracing and isolation must be continued for positive cases.

We are a long way away from overcoming the pandemic. Therefore, we must not lower our guard. While the authorities need to focus on organising vaccination, serological surveys and genome typing, the public needs to stick to masking, avoiding crowded places and going unhesitatingly for the jab.