The Union Health Ministry could take another six weeks or so to decide whether mixing of Covid vaccines is effective. The Ministry is awaiting data from “a few more studies”, a senior official told BusinessLine.

According to the official, there is still “no good scientific study” to prove that mixing of vaccines is an effective treatment alternative.

“A few more studies are on... some two or three. And an idea of efficacy of mixing two or more vaccines can emerge in some six-odd weeks or so. We still do not have good scientific study to support or approve mix-and-match of vaccines at this moment,” the official added.

Incidentally, vaccine manufacturer Biological E’s protein sub-unit vaccine for Covid, Corbevax, has received approval from the drug regulator as a heterologous booster in adults — those who have received Covishield or Covaxin as their first or second dose can take it as a booster shot.

Mixing-and-matching of Covid-19 vaccines is not allowed in India, and the third dose needs to be the same vaccine used for the first and second jabs.

India’s booster shot progress “has not been up to the mark”, say Health Ministry officials. While campaigns such as Har Ghar Dastak are being ramped up to boost precautionary dose coverage, some State governments have also started administering the third dose free of cost.

“Internal reviews say third dose coverage is poor. So, we are working on how to reach out to more people and create awareness on the same,” said the official, adding that the recent breakthrough infections were due to the poor response to booster shots and lack of Covid-appropriate measures, followed by increase in travel.

Officials say additional genome data have been sought from States where increased breakthrough infections have been reported.

BA2 sub-lineage

Meanwhile, the BA2 variant of Omicron and its sub-lineages, have been found to be the “dominant cause of breakthrough infections in the country”, accounting for 85 per cent of the new cases.

The BA4 and BA5 – the two other variants – account for the remaining 15 per cent of infections

“Current genome data show BA2 as the dominant variant and its sub-lineages as cause for breakthrough infections. There is still no new variant or any new variant of concern that we found from studying the data,” said the official.

Hospitalisations continue to be low, and deaths have been caused primarily due to co-morbidities or pre-existing conditions. “In most cases, the person was detected with Covid only when he came for treatment of a pre-existing condition, that’s what our findings say,” the official added.

India, on Monday, reported 12,781 fresh Covid-19 cases and 18 deaths. 11 reconciliation from Kerala; three fresh fatalities from Delhi and one each from Uttar Pradesh, Punjab, Karnataka and West Bengal, were reported, according to Union Health Ministry data. Active cases comprise 0.17 per cent of the total infections. The national Covid recovery rate was recorded at 98.62 per cent. The daily positivity rate was recorded at 4.32 per cent and weekly positivity rate at 2.50 per cent.

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