COVID-19: Delta Variant May Infect Those Who Received Covishield/Covaxin, Study; Should I Still Get Vaccinated

The Delta Variant, initially detected in India in October last year, is highly infectious and has been reported in 60 countries now. According to separate studies conducted by AIIMS (Delhi) and the National Centre for Disease Control (NCDC), it was suggested that the Delta variant could escape antibodies from one or both doses of Covishield and Covaxin.

So, according to the new study findings, getting jabbed with both doses of vaccine, Covaxin or Covishield, does not necessarily make you immune to the Delta variant of COVID-19 [1].

COVID-19 Delta Variant And Vaccination: What Does Studies Say?

The Delta variant, scientifically termed as B.1.617.2, was earlier called the 'double mutant' virus or the 'Indian variant', was officially assigned the name by the WHO. As per WHO, the Delta variant was the primary cause behind India's devastating second wave. The first case of the Delta variant in India was discovered in the state of Maharashtra [2].

The Delta variant of COVID-19 or the B1.617.2 highly transmissible variant of concern (VOC). The World Health Organisation has categorised it as a VOC because there has been a significantly increased transmissibility [3].

According to the reports from India, the symptoms of the Delta variant are hearing loss, gangrene, gastric problems, loss of appetite, and severe blood clots, which have not been reported in COVID patients infected with the Beta and Gamma variants [4].

Amidst these comes the new findings from two different studies, where both claim that the Delta variant can affect people who are vaccinated. The infections were closely investigated through genome sequencing, closely overlapping and mirroring the COVID-19 cases in the state of Delhi to understand vaccine efficacy.

COVID-19 Delta Variant: Everything You Need To Know About The 'Variant Of Concern'

Here are the important points from the studies:

The AIIMS Study:

• The AIIMS study shows that the Delta variant is possibly the reason behind the majority of breakthrough infections in India.
• Done in association with the Institute of Genomics and Integrative Biology (IGIB) and was carried out on 63 subjects who had breakthrough infections, 36 of whom had received two doses, while 27 had gotten one dose of vaccine.
• Of the 63 subjects, ten had received Covaxin and 53 had received Covishield doses.
• 76.9 per cent of infections by the Delta variant were recorded in people who had received a single dose and 60 per cent in people who had received both doses.
• While no deaths were reported in the 63 subjects, but almost all cases reported high-grade unremitting fever for 5-7 days.

The NCDC-IGIB Study:

• The infections because of the Delta variant seemed to affect people who took the Covishield vaccine.
• The Delta breakthrough infections were seen in 27 patients who had taken that vaccine, with the infection rate at 70.3 per cent.

What Does This Mean For COVID-19 Vaccination?

• While the vaccine's protection against the Delta (and even Alpha) variants may be reduced, the severity of infection appeared to be unaffected [5].
• The new findings contradict the previous studies, such as the one by the National Institute of Virology in Pune, the ICMR and Bharat Biotech (not yet peer-reviewed), indicating Covaxin offers protection against both the Delta and Beta variants.
• Viral load at the time of diagnosis was high in all the patients irrespective of vaccination status or type of vaccine received.
• Genome sequencing of the vaccine breakthrough of infection was investigated, and the variants of concern B.1.617.2 and B.1.1.7 comprised the majority [6].
• The proportions of the variants found in the study participants who were vaccinated were not significantly different in comparison with the population prevalence of the variants during this period with high community transmission.
• Prior infections, high seropositivity and partial vaccination are "insufficient impediments" to the spread of the Delta variant, found the scientists, meaning those three are not enough to stop the variant from entering your body and wreaking havoc.

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Should I Still Get Vaccinated Against COVID-19?

Experts stress the importance of getting vaccinated, irrespective of the suggested ineffectiveness of the vaccines. Getting vaccinated is the only way to minimise the chances of COVID infection and the rate of severity in people [7].

In addition to this, a statement by Dr Anthony Fauci (the medical advisor to the United States President) suggested that extending intervals between vaccine doses could leave people vulnerable to infection by one of the COVID-19 variants in circulation [8]. While Dr Fauci was shining a light on the ideal interval between doses for mRNA such as the Pfizer and Moderna, previous studies on the majority of the COVID-19 vaccines had mentioned the same [9][10].

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On A Final Note...

Since the new strains of the virus have the ability to evade immune responses, there are chances that the vaccines may not be very effective against them. Both the studies are yet to be peer-reviewed. Previously, several studies had mentioned that even if people contract the virus post-vaccination, the severity of the disease is often reduced.