Vaccinating older children and slowing down the relaxation of coronavirus restrictions are among measures that could help to prevent a third wave of Covid in the UK, according to a report from an organisation set up by the former prime minister Tony Blair. The government’s roadmap suggests all Covid restrictions could be lifted in England on 21 June. However, scientists have warned that even with an ongoing vaccination programme, the plan could lead to a resurgence of the virus and thousands, if not tens of thousands, of additional Covid-related deaths by summer next year. It is a scenario the prime minister, Boris Johnson, himself has acknowledged, saying on Monday another wave is a possibility we have “got to be realistic” about. However, the Tony Blair Institute for Global Change (TBI) has released a report saying a third wave is not inevitable, should three key actions be taken. “A further surge in hospitalisations and deaths is preventable if the right policy decisions are made in good time,” the report states. “But the government needs to begin preparing the ground now.” The report scrutinises expert modelling that was presented to the government, to identify key factors that could drive a third wave. The authors then used their own modelling to highlight three changes to the current government plans that could help avert such a situation. The first change is to either speed up vaccine rollout or delay the complete relaxation of coronavirus restrictions by a month. This, they say, would reduce the problem of the herd immunity threshold being higher than the degree of population protection afforded by vaccines at the point restrictions are fully relaxed. The second is to widen the reach of the vaccination programme to include adolescents to boost the level of population protection, and the third is to shift the balance of vaccines offered so that mRNA vaccines such as the Pfizer/BioNTech or Moderna jabs make up a bigger slice of the vaccine pie. The latter recommendation, the authors say, is based on some research suggesting these mRNA jabs may be more effective at preventing infection. “While no one of the three measures is sufficient to prevent a further large wave of infections, the combined package achieves that aim,” the report states. Prof Christina Pagel, director of the clinical operational research unit at University College London and a member of the Independent Sage group, welcomed the report but said it did not consider the importance of border controls, a functioning test and trace system, and support for people to self-isolate. She also noted that recent studies have suggested differences in the impact of the Pfizer/BioNTech and Oxford/AstraZeneca jab on infections may be small. The study also assumed that any new variants of the virus would not affect the efficacy of Covid jabs now in use – despite concerns that some variants may be able to, at least partially, evade immune responses, including those triggered by some Covid vaccines. But while vaccinating children against Covid is a complex issue, Pagel agreed there is a strong argument for adolescents to be given the jabs, if regulatory approval is granted. She also said the country would be in a much better position to fully lift restrictions should such such relaxation be delayed until all adults have had time to get at least some immunity from their first jab. “[A third wave] is only inevitable if you accept that the [government] roadmap is cast in stone. And it isn’t,” she said.