Is this clear? 我们等了一段时间，其间我们没观察到任何直接和明显的副作用, ... (waiting around for side-effects)
&quot;直接&quot; in &quot;其间我们没观察到任何(直接和)明显的副作用&quot; should be removed, because there's no such thing as 'indirect side effect'

If you meant &quot;immediate&quot;, the correct word is &quot;即時&quot; --&gt; &quot;其间我们没观察到任何(即時和)明显的副作用&quot;

&quot;我们等了一段时间，其间我们没观察到任何明显的副作用&quot;


You can use 並 (actually) to strengthen the connection between the two phrase


&quot;我们等了一段时间，其间我们並没观察到任何明显的副作用&quot;


Change 没观察到  to 沒有观察到

没 mainly used for &quot;without + object&quot;
沒有 is more suitable for &quot;have no + object&quot;

&quot;我们等了一段时间，其间我们並沒有观察到任何明显的副作用&quot;
&quot;我们等了一段时间，其间我们並沒有观察到任何即時和明显的副作用&quot;


You only need to state the subject &quot;我们&quot; once here


&quot;我们等了一段时间，其间並沒有观察到任何明显的副作用&quot;
&quot;我们等了一段时间，其间並沒有观察到任何即時和明显的副作用&quot;

Edit:
Other user rewrote the sentence in a more native way in his answer. That reduced the length of the original text greatly. In that case, I would just write &quot;等了一會，見沒有異狀，医生就走了&quot; (After waited for a while, seeing that there are no abnormalities, the doctor left.)
I don't know which the OP prefers, but I think it would be more beneficial for her, if I don't stray too far away from the original sentence that she came up with with her current writing ability