Coronavirus Live Updates: Delta strain 8 times less sensitive to COVID vaccine antibodies, study finds

·4 min read
Covid-19 vaccination in Chennai
A municipal worker drives an auto-rickshaw decorated with mock syringes through the streets to boost awareness among people on the importance of the Covid-19 vaccination in Chennai. (Photo by ARUN SANKAR/AFP via Getty Images)

The Delta variant is eight times less sensitive to antibodies generated by Covid-19 vaccine compared to the original Wuhan strain, found a study conducted on 100 healthcare workers across three centres in Delhi, including the Gangaram Hospital.

The study ‘Sars-Cov-2 B.1.617.2 Deltavariant Emergence and Vaccine Breakthrough: Collaborative Study’ also found that the variant has much higher capacity to infect more people than the Wuhan strain.

The collaborative study from India was conducted along with scientists from Cambridge Institute of Therapeutic Immunology & Infectious Disease.

“In an analysis of vaccine breakthrough in over 100 healthcare workers across three centers in India, the B.1.617.2 Delta variant not only dominates vaccine-breakthrough infections with higher respiratory viral loads compared to non-delta infections, but also generates greater transmission between fully vaccinated healthcare workers, as compared to other variants B.1.1.7 (Alpha variant) or B.1.617.1 (Kappa variant)," the findings of the study revealed.

The study found out that the Delta variant is less sensitive to neutralising antibodies from recovered individuals, with “higher replication efficiency" as compared to the Alpha variant.

In terms of its increased transmissibility, the study said that the mutant variant has enhanced spike proteins for attachment to the lung epithelial cells, which had provided it with a much higher capacity to infect many more people than the Wuhan strain.

“From this study it appears that we have to go miles before we sleep in case of Covid-19 pandemics. These mutations are bound to happen if we lower our guard and allow ourselves to fall prey to this virus giving it an opportunity to multiply and achieve better fitness with our Covid inappropriate behavior," said Dr Chand Wattal, Chairperson, Institute of Clinical Microbiology & Immunology, Sir Ganga Ram Hospital.

“This is a straight eye opener to the fully vaccinated people that you cannot lower guard in the name of vaccination. Virus is on prowl still looking of its prey. This mutant has come back with enhanced spike proteins for attachment to the lung epithelial cells which has provided it much higher capacity to infect many more people than the Wuhan strain,” he added.

Earlier, the Delhi government ordered the closure of the popular Lajpat Nagar market in south Delhi till further orders and the Rui Mandi in Sadar Bazar till July 6 for violation of COVID-19 norms, officials said on Monday. The order to close the markets was issued on Sunday by the Delhi Disaster Management Authority. Sub-Divisional Magistrate, South East District, Padmakar Ram Tripathi said in an order that an inspection was carried out by the COVID-19 appropriate behaviour enforcement teams at the Lajpat Nagar Central Market wherein 'gross violations' of guidelines was observed.

India saw a single-day rise of 39,796 new COVID-19 infections, which took the tally of cases to 3,05,85,229, while the death toll climbed to 4,02,728 with 723 more fatalities, the lowest in around 88 days, according to Union Health Ministry data on Monday.

The active cases have further declined to 4,82,071 and comprise 1.58 per cent of the total infections, while the national Covid recovery rate has improved to 97.11 per cent, the data updated at 8 am showed It said that there has been a decline of 3,279 active cases in a span of 24 hours.

The ministry said that 15,22,504 tests were conducted on Sunday, taking the total cumulative tests conducted for detection of Covd in the country to 41,97,77,457. The daily positivity rate was recorded at 2.61 per cent. It has been less than five per cent for 28 consecutive days, it said.

The weekly positivity rate has declined to 2.4 per cent, according to the health ministry.

The 723 new fatalities include 306 from Maharashtra, 76 from Kerala and 72 from Tamil Nadu, the ministry said.

It said that 4,02,728 deaths have been reported so far in the country, including 1,23,030 from Maharashtra, 35,367 from Karnataka, 33,005 from Tamil Nadu, 24,995 from Delhi, 22,640 from Uttar Pradesh, 17,799 from West Bengal and 16,110 from Punjab.

The Jammu and Kashmir administration on Sunday lifted the weekend curfew from five more districts thereby increasing the arch of relaxation to 13 districts of the union territory after significant improvement in the Covid-19 situation, officials said.

The government made vaccination and negative RT-PCR report mandatory for people visiting indoor shopping complexes, malls, restaurants and bars and indoor sports complexes.

While relaxations were announced for Rajouri, Poonch, Pulwama, Baramulla and Anantnag districts on Sunday, weekend curfew was lifted on June 20 in Jammu, Kathua, Samba, Udhampur, Bandipora, Budgam, Ganderbal and Shopian districts.