In the Journals: Developing a Vaccine against COVID-19

On April 3, 2020, Jon Cohen, a journalist writing for Science, published a review of where things stand on the development of a vaccine to prevent COVID-19 (Cohen J. Vaccine designers take first shots at COVID-19. Science. 2020 Apr 3;368(6486):14-16).

On March 16, 2020, the first vaccine to go into clinical trials was that of Moderna, a well-financed biotechnology company located in Cambridge, Massachusetts. Moderna uses messenger RNA (mRNA) containing the gene that codes for the COVID-19 spike protein (which is the cell-attachment protein) to induce protective antibodies. The trial consisted of 45 people between 18 and 50 years of age who were divided into three groups of 15 each to determine the optimal dose. The advantage of the mRNA approach is that strong immune responses can be induced with only 1 microgram, meaning that 1 gram could vaccinate a million people.

At the time of publication of Cohen’s article, more than 40 companies or academic centers were actively involved in making a COVID-19 vaccine. Eighteen were making a protein subunit vaccine, eight were making mRNA vaccines, three were making DNA vaccines, eight were using non-replicating viral vectors, five were using replicating viral vectors (such as adenovirus 5 or adenovirus 29), two were using inactivated viruses, two were using attenuated viruses, and one was using virus-like particles (similar to HBV and HPV vaccines).

There is every reason to believe that the development of a COVID-19 vaccine can be successful. Animal model studies for vaccines against two other novel coronaviruses (SARS and MERS) were promising. And COVID-19 does not appear to mutate in a manner similar to influenza. Moderna believes that an efficacy trial involving about 5,000 people could be completed by January 2021.