Covishield

Covishield is the brand name under which the Serum Institute of India (SII), Pune, manufactured the Oxford–AstraZeneca COVID-19 vaccine (technical designation ChAdOx1 nCoV-19, also marketed globally as Vaxzevria) under a 2020 licensing agreement. It is a viral-vector (non-replicating) vaccine: the gene encoding the SARS-CoV-2 spike protein is inserted into a weakened chimpanzee adenovirus (ChAdOx1), which on injection prompts host cells to express the spike antigen and trigger a protective immune response. The vaccine was developed by the Jenner Institute, University of Oxford. India's Central Drugs Standard Control Organisation (CDSCO), on the recommendation of the Subject Expert Committee, granted Covishield Emergency Use Authorisation on 3 January 2021, alongside Bharat Biotech's indigenous Covaxin. Mass administration began on 16 January 2021, the launch date of India's nationwide COVID-19 vaccination drive.

Covishield is administered intramuscularly in a two-dose regimen. India initially set a 4–6 week dosing interval, later revised to 12–16 weeks in May 2021 on advice of the National Technical Advisory Group on Immunisation (NTAGI), based on evidence that a longer gap improved efficacy. A key logistical advantage over mRNA vaccines was its storage requirement of standard refrigeration (2–8°C), suiting India's existing cold-chain infrastructure. The Serum Institute, the world's largest vaccine manufacturer by volume, scaled production to supply both India's domestic programme and the global COVAX facility, while exports were temporarily curtailed during India's devastating second (Delta variant) wave of April–May 2021 under the so-called "vaccine maitri" pause.

Covishield accounted for the overwhelming majority of doses delivered under India's CoWIN platform, which by 2022 had recorded over 2 billion administered doses nationally. The vaccine became internationally salient in 2024 when AstraZeneca, in UK High Court litigation, acknowledged that the vaccine could, in very rare cases, cause Thrombosis with Thrombocytopenia Syndrome (TTS) — a clotting disorder. AstraZeneca subsequently announced in 2024 the global withdrawal of the vaccine, citing commercial reasons and a surplus of updated variant-specific vaccines. As of 2026, Covishield is no longer in active production, but it remains a defining case study in vaccine diplomacy, regulatory science, and public-health logistics.

For the UPSC examination, Covishield is most relevant to General Studies Paper III (Science & Technology — developments and applications, and indigenisation of technology) and to current-affairs questions on health governance. Prelims questions typically probe the platform type (viral vector versus mRNA versus inactivated), the manufacturer (Serum Institute), and the distinction from Covaxin (inactivated whole-virion, by Bharat Biotech). Mains answers may invoke Covishield to discuss India's pharmaceutical manufacturing capacity ("pharmacy of the world"), vaccine maitri diplomacy, the COVAX initiative, the CoWIN digital governance model, and ethical questions of emergency authorisation and adverse-event compensation. Candidates should clearly differentiate Covishield (Oxford–AstraZeneca licence, viral vector) from Covaxin (wholly indigenous, inactivated), as the two are frequently confused.