Johnson and Johnson announced today that its coronavirus vaccine showed significant efficacy in clinical trials for preventing COVID-19.
The vaccine trial was designed to measure how well the vaccine prevented COVID-19 related illness, four weeks after a single shot. It was 66% effective overall at preventing moderate and severe disease, a result that covers a wide range of variation depending on geography: it was 72% effective at protecting against moderate to severe illness in the United States, but it was 66% effective in Latin America and 57% effective in South Africa, where SARS-CoV-2 variants have taken root.
While the vaccine was less effective at preventing actual COVID-19 infections (66%) then the RNA vaccines from BioNTech-Pfizer and Moderna (95%), it has several advantages. Among them, it is a single dose vaccine that simply requires refrigeration.
The vaccine uses a modified human cold (adenovirus) virus that contains the genetic coding for the spike protein from SARS-CoV-2. It then makes the protein when. it gets into human cells.
The results, reported in a news release, did not give any specific findings from the trial, but still put the vaccine on timeline for approval in the United States, especially given the logistical advantages that could simplify distribution and expand access to shots. The vaccine may be particularly useful in developing countries worldwide.
Company officials emphasized the vaccine’s 85% reduction in preventing severe illness, and there were no cases of COVID-19 related hospitalization and death in people who received the vaccine. The five COVID-19 related deaths in the trial were all in people who received the placebo.
The one concern with this vaccine is that it may not prevent infections in immunize people. This could allow for ongoing COVID viral replication and selection of variant coronaviruses that would be resistant to vaccines. One thing that may resolve this is a trial giving two doses of this vaccine, similar to the RNA vaccines. There is hope for this approach because the efficacy of one dose of the RNA vaccines looks much like one dose of this vaccine.
I would think that you could start vaccinating with the Johnson and Johnson vaccine as soon as it is available, then administer a second dose if the new study shows it improves efficacy.