There are more promising signs from ongoing efforts to develop a vaccine that's effective in preventing COVID-19: Two early trials, one from the University of Oxford, and one from a group of researchers in Wuhan funded in part by the National Key R&D Programme of China. Both early trials showed efficacy in increasing the presence of antibody responses to SARS-CoV-2, the virus that leads to COVID-19, and also indicated that these prospective vaccines were safe to administer based on available information.
The University of Oxford study is one of the leading vaccine development efforts in the world, and among those that are furthest along in development. The results of their study covered 1,077 participants, all of whom were health adults aged between 18 and 55 with no prior confirmed history of having contracted SARS-CoV-2. That's important because they received double randomized trials of the vaccine candidate, or an existing vaccine for meningitis as a control acting as a placebo. The results showed that across the group, 100 percent of the participants had demonstrated neutralizing antibody responses by the end of the course, which include a booster does.
Additionally, while some participants exhibited side effects, including "pain, feeling feverish, chills, muscle ache, headache and malaise," none of these represented what the researchers consider serious reactions, and these were also mitigated with use of paracetamol (standard painkillers available over the counter). Patient reactions were monitored for 28 days following the administration of the vaccine.
Oxford's team is now ready to move on to its Phase 3 trial, which is a large-scale human trial that is effectively the last major step before it moves on to potential approval, production and distribution. That's a time consuming process, but it does put this development on pace for a remarkably fast research and development process relative to prior vaccines.
Meanwhile the study in China covered health adults 18 or older, and included 603 participants, screened down to 508 who received either the vaccine candidate or a placebo. The participants also showed no adverse reactions, according to the researchers, and they're also now likely to move on to a phase 3 development program.
Earlier this month, Moderna also announced promising early results from its phase 1 trial, but that was limited to just 45 participants between 18 and 55, and indicated some potentially serious side effects that will need to be watched in later, larger trials. These new results, while also early and requiring further development and research, are much more encouraging given the scale of both trials.
It is very early to make too many assumptions about what these early trials indicate, however. For instance, we still don't really know how effective antibodies are in patients that have recovered from having COVID-19 once, so a lot more investigation is required by scientists in better understanding the efficacy of antibodies, and potentially vaccines, over the long term.