Self-harming among inmates of a Worcestershire prison remain "stubbornly high", monitors have said.
The Independent Monitoring Board (IMB) said almost half of all medical callouts had accounted for self-harm incidents.
The IMB said it was concerned at-risk prisoners at HMP Hewell may not be being identified in time, under a restricted regime due to the pandemic.
The prison said conditions had improved during the pandemic.
The Redditch prison remains under the Prison Performance Support Programme, a replacement for the special measures the jail was placed in in 2018, IMB said.
The prison had an "effective" response to the pandemic but conditions were still a concern, the board said.
There were 359 incidents of self-harming between 1 March and 30 September, which represents 1 in 6.7 of the prison population, the IMB said in its annual report.
That equated to 49% of all healthcare responses during the six months.
"The question remains as to whether, with the restricted regime, prisoners at risk of suicide or self-harm are pre-emptively identified before an incident takes place," they added.
Although the prison showed a strong to the pandemic - with the last positive case among prisoners being reported in April - the board said it was concerned about a detrimental effect on the conditions in which prisoners were held.
In September, the chief inspector of prisons said conditions were "wholly unacceptable" with social distancing restrictions leaving some prisoners without access to a shower or fresh air for weeks.
While inmates had to be kept safe, the "collateral damage" to their broader welfare "cannot be underestimated", the IMB said.
Rodger Lawrence, IMB Hewell chairman, said the community should be "very proud" of the prison's response to the pandemic and board members had seen improvements at the jail.
"Not only were they responding to the national emergency, but they had a new governor determined to raise standards and bring the prison into the 21st Century," he said.
A Prison Service spokesperson said dogs have been introduced at several "challenging" prisons to help crack down on violence and crime.
"Drugs fuel self-harm and violence and we know the new security measures at Hewell are already having a positive impact," a spokesman said.