Covid-19 Wrap-up: Against a more virulent Delta, is booster our best shot?

All you need to know about the coronavirus right now

As India's daily Covid-19 cases have been on a steady decline, with Monday's cases at a 160-day low, the focus has now shifted towards vaccination and boosters to ensure that the progress is not lost.

Indigenously developed Zydus Cadila's Covid-19 vaccine ZyCoV-D on Saturday received approval for Emergency Use Authorisation from the Drug Controller General of India and it will be administered to people 12 years and above. It is India's first vaccine approved for children above the age of 12.

It is a three-dose vaccine and has been developed in partnership with the government's Department of Biotechnology. It can be applied using a needle-free injector. This is the world's first DNA-based vaccine against coronavirus. The vaccine, when injected, produces the spike protein of the SARS-CoV-2 virus and elicits an immune response, which plays a vital role in protection from the disease as well as viral clearance.

Zydus Cadila said it would be able to produce around 3-4 crore doses of its DNA vaccine by December as against the government’s hope of getting 5 crore doses from the Gujarat- based maker of India’s first Covid-19 vaccine for kids.

The Cadila vaccine approval comes at a time when an expert panel under the National Institute of Disaster Management (NIDM), the Ministry of Home Affairs (MHA), has warned that the third wave of Covid-19 may peak in October. In its recent report to Prime Minister's Office (PMO), the committee has sought better medical preparedness for children who might be at similar risk as adults.

Meanwhile, the US FDA has given complete approval to Pfizer vaccine to be used in people above the age of 16.

The Central government and DCGI may give their nod to Covaxin for children soon for emergency use. The administration of two doses of vaccination has been completed among children and blood samples have been sent for the third time to check the effectiveness in terms of producing antibodies among children. As the trials will take another 5 to 6 months from now to be completed, they can't wait till then in the current circumstances to release the vaccination for children.

Without a readily available jab for children yet, whether schools should be reopened or not, as fear of the third wave looms, still remains an undecided debate. Surveys conducted by several Bengaluru-based schools showed parents reluctant to send children to schools.

With the ebbing of cases and easing of restrictions, questions on the intensity of the third wave persist.

As the festival season has not yet ended, the effect of the relaxations and non-Covid appropriate behaviour by people who ventured out for celebrations and shopping would be seen in the test positivity rate (TPR) which, according to experts is expected to rise further from Saturday's 17.73 per cent. On Saturday, the number of fresh cases in Kerala were 17,106, almost half of the national total of 34,457

Evolutionary debate indicates we can expect coronavirus to favour virus strains that result in a steeper epidemic curve, producing more cases more quickly. In the short term, it’s highly likely evolution will continue to “fine tune” the virus. Its R value will continue to increase (more people will be infected in one generation; the serial interval will decrease (people will become infectious sooner) and variants will make vaccines less effective (vaccine evasion). But we don’t know how far these changes might go and how fast this might happen.

In some good news, researchers have identified an antibody that is highly protective at low doses against a wide range of variants of the SARS-CoV-2 virus which causes Covid-19. The findings, posted as a pre-proof in the journal Immunity, could help develop new antibody-based therapies that are less likely to lose their potency as the virus mutates.

The talk around a booster shot is gathering pace. The rollout of a third dose of Covid vaccine has sparked debate on ethical and political grounds since a large swath of the population is yet to receive any inoculation. But the case for boosters on scientific grounds is building. The reason is delta. The most infectious coronavirus variant to emerge so far is in a race with the human immune system, and there is mounting evidence that delta is winning -- at least initially.

However, All India Institute of Medical Science (AIIMS) director Dr Randeep Guleria said that India does not have enough data as of now on the need for a third Covid-19 vaccine dose or a booster shot.