Trending Clinical Topic: COVID-19 Vaccine

Ryan Syrek


July 31, 2020

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Encouraging initial results from phase 1/2 trials of vaccines against SARS-CoV-2 captured a great deal of attention this week. Anthony Fauci, MD, director of the National Institute of Allergy and Infectious Diseases, reiterated his belief that a vaccine will very likely be available by the end of 2020. In an interview with John Whyte, MD, MPH, chief medical officer at WebMD, Fauci described how quickly the vaccine development is progressing.

These comments came alongside the release of three sets of data showing positive responses to investigational vaccines. A phase 1 trial of a vaccine from Moderna found that all 45 participants developed an immune response, with no significant safety issues. Moderna's vaccine uses messenger RNA, and study participants received two vaccinations 28 days apart. Phase 2 results are expected soon, and phase 3 testing is now underway.

A phase 1/2 trial of a vaccine against SARS-CoV-2, conducted by the University of Oxford, showed similarly promising results. That vaccine is made from a weakened version of an adenovirus that causes infections in chimpanzees, which has been genetically modified so that it cannot grow in humans. The findings show that the vaccine provoked a T-cell response that peaked 14 days after vaccination and an antibody response within 28 days. The investigation is also now moving into phase 3 trials.

Results of a phase 2 trial for another adenovirus-based vaccine were recently released. Chinese researchers found that their vaccine produced immune response in the majority of participants at 28 days post-vaccination. Although findings indicated no significant safety issues, more than half of participants had high preexisting immunity to the specific adenovirus vector used by the vaccine, which may impair immune response to the vaccine. A phase 3 trial is planned.

Leaders of Operation Warp Speed, the United States' fast-track approach to vaccine development, have held firm to an end-of-year timeline. At a congressional briefing, however, executives of five firms working on COVID-19 vaccines reported that the target goal for major data results is next year. Those executives also pointed to trust in vaccination as a major concern moving forward. They called for education campaigns and outreach about COVID-19 vaccines now, while research is still being conducted, in order to ready the general public for when vaccination becomes available.

Approval of a COVID-19 vaccine is arguably one of the most anticipated scientific developments in modern medical history. As trials move forward and vaccination becomes an increasingly real possibility, the topic may well become the single biggest top trending subject we've ever documented.

Read more clinical information about COVID-19.


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