‘Delta strain also hits vaccinated’: INSACOG consortium

The Indian SARS-CoV-2 Genomic Consortium (INSACOG), the consortium of 28 national genetic laboratories in India, has warned that vaccination breakthrough cases of Covid-19 are expected to happen in the country.

The multi-agency genetic sequencing consortium said that vaccination breakthroughs are common during Delta outbreaks and are expected in India as well. “Sequencing of vaccination breakthroughs in India is showing a very large proportion of Delta variant,” the consortium said.

The alert on Delta variant implies that vaccinated individuals do not get a free pass from the Delta variant of SARS-CoV-2. Persons who are vaccinated are as susceptible as unvaccinated for getting infected with Delta variant. However, the benefit from Covid vaccines is that they are efficient in reducing the severity, death and hospitalisation among vaccinated persons.

In the context of vaccination breakthrough cases, the INSACOG said United Kingdom has seen many instances where vaccinated persons have tested positive for Covid-19. “There has been concern about whether increasing vaccination breakthroughs in India are because of a new variant. It is noted that UK, with a population of about 6.7 crore, has reported about 18 lakh cases and 1.2 lakh vaccination breakthroughs with Delta, since April 2021,” it said.

A recent UK study of Covid infections by researchers from University of Oxford and published in preprint form on August 19, has said that the Pfizer-BionTech and Oxford-AstraZeneca (known as Covishield in India) vaccines are effective against the Delta variant of SARS-CoV-2. However, their protection drops or wanes away over a period of time.

“Vaccination breakthroughs are common during Delta outbreaks and are expected in India as well. Concern regarding appearance of new variants should be calibrated in the context of such data. As of now sequencing of vaccination breakthroughs in India is also showing a very high proportion of Delta variant,” the consortium in its update, said.

The Delta variant continues to remain a major Variant of Concern (VOC) in India. “Continuing outbreaks across India are attributable to Delta variant, a susceptible population, reduced vaccine effectiveness in blocking transmission, and opportunities for transmission. Vaccination continues to be very effective in reducing severe disease and death,” the INSACOG made it clear.