Given that the first dose will offer some degree of protection, a longer gap will allow the state to cover as many as possible with vaccines in short supply in the early part of the inoculation campaign. “Every beneficiary will be given two doses/shots of the vaccination with a gap of four-six weeks,” according to the Maharashtra notification that ET has seen.
It’s not clear if other states will also follow this policy.
The standard dosage for Covishield and Covaxin vaccines is two jabs, with the second given after four weeks. The Indian government has procured an initial 12 million doses from Serum Institute, which makes Covishield, and Bharat Biotech, maker of Covaxin.
One vial of Covishield contains 10 doses, while one vial of Covaxin has 20.
In the first phase, the health ministry said healthcare workers, followed by frontline workers and those 60 and above will be inoculated.
Will Solve Problem of Storage
“We may have another lot in due course of time,” said Mumbai additional municipal commissioner Suresh Kakani, when asked about using up vaccines as soon as they are received. Such a plan will also solve the problem of storage.
The idea of delaying the second dose was first mooted by the UK’s Joint Committee on Vaccination and Immunisation. It said giving one dose to at-risk groups will protect the largest number in the shortest possible time and will also have a similar impact on reducing mortality, severe disease and hospitalisations.
An Indian expert said, based on the data, the gap could be even longer for the vaccine made by SII based on AstraZeneca-Oxford technology.
“The evidence suggests that the efficacy for the SII/AZ vaccine is maximum when the second dose is given after 12 weeks,” said Giridhara Babu, head, lifecourse epidemiology, Public Health Foundation of India. “This will help in better efficacy while expanding the population coverage in phased manner… Planning the second dose over a three-month duration provides ample time for planning and procurement for other vaccines and logistics.”
The UK committee had recommended delaying the second dose by up to eight to 12 weeks.
“With most vaccines, an extended interval between the prime and booster doses leads to a better immune response to the booster dose,” the UK’s vaccine action committee had said in its recommendation in December. “There is evidence that a longer interval between the first and second doses promotes a stronger immune response with the AstraZeneca vaccine. There is currently no strong evidence to expect that the immune response from the Pfizer-BioNTech vaccine would differ substantially from the AstraZeneca and Moderna vaccines.”
In a separate letter, the Union health ministry has asked state governments to delay vaccinations for those with active Covid symptoms by four to eight weeks. Those who have received monoclonal antibodies or those who are acutely unwell should also delay getting vaccinated. However, those with a past history of Covid-19 infection, i.e. with antibodies against the disease, can get themselves vaccinated.