COVID-19 vaccine.


COVID-19 vaccine

On 16 January 2021 India started its national vaccination programme against the SARS-CoV-2 virus which has caused the COVID-19 pandemic. A COVID‑19 vaccine is a vaccine intended to provide acquired immunity against severe acute respiratory syndrome coronavirus 2 (SARS‑CoV‑2), the virus causing coronavirus disease 2019 (COVID‑19) COVID‑19 vaccines have demonstrated efficacy as high as 95% in preventing symptomatic COVID‑19 infections.

Many countries have implemented phased distribution plans that prioritize those at highest risk of complications, such as the elderly, and those at high risk of exposure and transmission, such as healthcare workers. As of 30 March 2021, 574.25 million doses of COVID‑19 vaccine have been administered worldwide based on official reports from national health agencies. AstraZeneca-Oxford anticipates producing 3 billion doses in 2021, Pfizer-BioNTech 1.3 billion doses, and Sputnik V, Sinopharm, Sinovac, and Johnson & Johnson 1 billion doses each. Moderna targets producing 600 million doses and Convidecia 500 million doses in 2021. By December 2020, more than 10 billion vaccine doses had been preordered by countries, with about half of the doses purchased by high-income countries comprising 14% of the world's population.

According to studies published in 2005 and 2006, the identification and development of novel vaccines and medicines to treat SARS was a priority for governments and public health agencies around the world at that time. As of 2020, there is no cure or protective vaccine proven to be safe and effective against SARS in humans. There is also no proven vaccine against MERS. When MERS became prevalent, it was believed that existing SARS research may provide a useful template for developing vaccines and therapeutics against a MERS-CoV infection.

The urgency to create a vaccine for COVID‑19 led to compressed schedules that shortened the standard vaccine development timeline, in some cases combining clinical trial steps over months, a process typically conducted sequentially over years.

National governments have also been involved in vaccine development. Canada announced funding for 96 research vaccine research projects at Canadian companies and universities, with plans to establish a "vaccine bank" that could be used if another coronavirus outbreak occurs, and to support clinical trials and develop manufacturing and supply chains for vaccines.

Large pharmaceutical companies with experience in making vaccines at scale, including Johnson & Johnson, AstraZeneca, and GlaxoSmithKline (GSK), formed alliances with biotechnology companies, governments, and universities to accelerate progression to an effective vaccine.

On 13 March 2021, the Centers for Disease Control and Prevention reported 1,637 deaths following Covid-19 vaccinations. A comparison between the rates of deaths following the vaccines for Covid-19 and those for influenza "raises questions", according to the CDC.

A clinical trial design in progress may be modified as an "adaptive design" if accumulating data in the trial provide early insights about positive or negative efficacy of the treatment.

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With Regards,

Sarah Jhonson

Advances in Pharmacoepidemiology and Drug Safety

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