The Wales Audit Office says Wales has made "excellent progress" in vaccinating its population against Covid-19 but "a clear plan is now needed" for the challenges which lie ahead.
The report by the Wales Audit Office said the coronavirus vaccination programme in Wales has been "delivered at significant pace with local, national and UK partners working together to vaccinate a significant proportion of the Welsh population".
It also found that whilst vaccine milestones have been achieved, a longer-term plan is needed that keeps pace with evolving knowledge of the virus and vaccines and considers how to maintain a resilient vaccine workforce and good levels of uptake within the community.
The Welsh Government says it has set out plans for booster jabs and will work with the NHS to ensure no one is left behind.
The Wales Audit Office found that vaccination rates in Wales, were the highest of the four UK nations, and some of the highest in the world.
It also highlighted that overall vaccine uptake is high, but there are concerns about the lower uptake for some ethnic groups and in deprived communities, as well as non-attendance at booked appointments in general.
However, it highlighed how vaccine supply is the "most significant factor" affecting the rollout of the Covid-19 vaccine in Wales and is dependent on international supply.
It says with limited stock held in Wales, interruptions to expected supply "could seriously impact the pace" of the rollout.
As at the end of May 2021, the Wales Audit Office says:
3.3 million vaccinations were given in Wales;
84.4% of the 2.52 million eligible adults, have received a first dose;
66.1% of the 1.68 million in the 'at risk' priority group, have received a second dose;
Only 0.4% of all vaccines have been considered unsuitable for use;
The cost for 2020-21 has been £29.4 million, excluding redeployed staff and the cost of the vaccines.
Auditor General, Adrian Crompton said: "Wales has made great strides with its COVID-19 vaccination programme. Key milestones for priority groups have been met and the programme is continuing at pace with a significant proportion of the Welsh population now vaccinated.
"This is a phenomenal achievement and testament to the hard work and commitment of all the individuals and organisations that have been involved in the vaccine roll out to date.
"However, the job is far from over. A longer-term plan is needed that moves beyond the existing milestones and considers key issues such as resilience of the vaccine workforce, evolving knowledge of vaccine safety, the need for booster doses, and maintaining good uptake rates - especially in those groups that have shown some hesitancy in coming forward for their vaccinations."
A Welsh Government spokesperson said: "We welcome this report which recognises Wales is leading the way in vaccines rollout and we want to thank Wales' fantastic vaccination teams, which have been planning and delivering our world-leading programme, for their hard work and dedication.
"This week we set out our longer-term plans, including how we would roll-out booster vaccines, and how we will continue to work with NHS Wales to ensure no one is left behind."