Janssen vaccine produced in the Netherlands shows 66 percent efficacy

The vaccine produced by Belgian company Janssen shows a single-dose efficacy of 66 percent. This is lower than the other vaccines that have thus far been approved, however, this may not matter too much. 

The vaccine developed in Leiden under parent company Johnson & Johnson appears to be less effective than others. The first vaccine that was approved, developed by Pfizer/BionTech, shows 95 percent efficacy. AstraZeneca’s vaccine has an average efficacy rate of 70 percent, and the vaccine developed by Moderna shows an efficacy rate of 92 percent. On Friday, US-based company Novavax announced that the phase three trial of its vaccine indicated an efficacy level between 86 to 89 percent.

However, experts say that this may not necessarily be a disadvantage. In an interview with EenVandaag, virologist Marjolein Kikkert explains that the mix of different vaccines may in fact be an advantage. “I think it is very beneficial that we will soon have a set of vaccines that each have their strengths and weaknesses so that they can complement each other.”

One of the main advantages of the Janssen vaccine is that the 66 percent immunity rate can be achieved after one jab, whereas the other vaccines currently on the market require two doses. Moreover, this vaccine can be stored at four degrees, which is fridge temperature. “Logistically, this means that it will be much easier to distribute than, for example, a vaccine that needs to be stored at minus 80 degrees,” explains Kikkert. 

The virologist added that these percentages must be understood in relative terms. She argues that two-thirds of the people who will receive the Janssen vaccine will “become completely immune.” For the remaining one-third, “it will significantly reduce the risk of becoming severely ill,” she adds. 

The combination of various vaccines may thus lead to the desired ultimate goal of herd immunity.