The 'delta' variant of Covid-19, the version first detected in India in October last year, is capable of infecting people even after they have received both doses of the Covaxin or Covishield vaccines. This development comes after separate studies were done by AIIMS (Delhi) and the National Centre for Disease Control (NCDC). It is important to note that neither study has been peer-reviewed as yet. AIIMS study suggests the 'delta' variant - which others, including one by British health authorities, say is between 40 & 50 per cent more infectious than the 'alpha' version first reported from the UK - is likely behind the majority of breakthrough infections in India. Data from the NCDC-IGIB study indicated that breakthrough infections due to the 'delta' variant seemed to affect people who took Covishield. Data from both studies indicated the 'alpha' variant is also proving resistant to Covishield and Covaxin, but not as significantly as the version first reported from India. AIIMS-IGIB and NCDC-IGIB studies, however, appear to contradict a joint investigation by the National Institute of Virology in Pune, the ICMR and Covaxin manufacturers Bharat Biotech. That study, which has also not yet been peer-reviewed, indicated Covaxin offers protection against both the ‘delta’ & ‘beta’ variants. Meanwhile, the Delta coronavirus variant of concern, first identified in India, is believed to be 60% more transmissible than the Alpha variant which was previously dominant in Britain, a prominent UK epidemiologist said on June 9. Watch the video to know more.