OH, C$_3$, and C$_2$ were not detected anymore after the beginning of November at 1.4 au and NH early October at 1.2 au. We found that like for the previous apparitions [@Schleicher1987], the production rates pre-perihelion are larger by more than a factor two than post-perihelion. It is clear from Figure \[fig:gas\_rate\] that the asymmetric activity is seen for all species and this behaviour does not change over the various apparitions [@Schleicher1987; @Combi2011] as shown also in Figure \[fig:rate\_H2O\] for the water production rate. The same behavior has been reported for the parent molecules (H$_2$O, CO, CH$_4$, C$_2$H$_2$, C$_2$H$_6$, NH$_3$ and CH$_3$OH) production rates derived at infrared wavelengths during the 2018 passage [@Faggi2019; @Roth2020]. This might due to the shape of the nucleus and its spin-axis orientation. This effect has been observed in several comets such as 9P/Tempel 1 [@Schleicher2007], 81P/Wild 2 [@Farnham2005] and also for comet 67P/Churyumov-Gerasimenko [@Schleicher2006; @Opitom2017]. It has been shown very clearly by Rosetta mission that the maximum activity of 67P was well associated to the illumination of the most southern regions, which were receiving the maximum of solar flux, and were subject to intense erosion [@Lai2019]. Recently, [@Marshall2019] has show for those three comets that 