Some 125,000 people went to the Southsea festival across August 27-29 with 200 receiving a Pfizer jab on site.
Portsmouth’s public health team said there were 952 cases between August 21-27, and 756 between August 29 to September 4.
There was ‘no spike’ in infections in any age group in the city following the event that saw The Streets and Manic Street Preachers perform.
Claire Currie, public health consultant Portsmouth City Council, said: ‘Any gathering with large numbers of people attending carries risks of spread of the coronavirus infection, and some cases appear to be linked to the festival.
‘However, we see no conclusive evidence in the data that the Victorious Festival impacted on Portsmouth's Covid-19 positive case rate.
‘In fact, case rates in Portsmouth were lower in the period after the festival than in the weeks preceding it - although they are now starting to creep upwards again, due in part to schools reopening after the summer break.’
She added there had been ‘good engagement with the Covid safety measures’ before and during the event.
Around 140 people who tested positive ahead of the major spectacle did not attend.
The infection rate went from 299 per 100,000 in the week to August 4, but rose to 489 in the week to August 30. However, this dropped to 379 in the week to September 6. It is not rising.
The consultant added: ‘Working closely with the event organisers, as we did, to make sure it was as safe as possible for everyone, seems to have paid off.
‘The measures they had in place followed the national government guidance and we strongly recommend other event organisers follow these to ensure infection case rates are kept as low as possible during these types of mass gatherings.
‘In particular, pre-event testing had a real impact on identifying asymptomatic cases so they could isolate and avoid unknowingly spreading the virus.’
But she warned infection rates remain high in Portsmouth and 20 per cent of eligible people have not yet had their first Covid dose.
At Victorious 914 supervised - and negative - lateral flow tests were done, with 91 of those at a pop-up unit in Palmerston Road. The health team also handed at 299 home test kits.
A council statement added: ‘There is no evidence of a spike in rates in any specific age groups that can be attributed to Victorious.’