Public health crisis is over - IF vaccines continue to work, says expert

Professor Sir Andrew Pollard, director of the Oxford Vaccine Group, said society would need to learn to live with Covid-19 going forward, and also suggested it was not feasible in the short-term to keep producing new vaccines for every variant.

It comes as an expert from Public Health England (PHE), also appearing in front of the Commons Science and Technology Committee, said the global pandemic would last another two years.

Sir Andrew told MPs that the emergence of new variants “will happen, is going to continue to happen” as he urged people to continue having vaccines.

He added: “But in the end, we’re going to have to come back to focusing on the really important public health issue, which is the hospitalisation and the death.

“And if those are disconnected – if transmission is disconnected by vaccine immunity from the severe disease to a large extent – then we’ll need to monitor new variants perhaps if we need to find new vaccines and so on, but we are going to have to live with it being in in our communities and transmitting.”

He continued: “That’s the key bit that we have to look at with future variants: if that very high protection against hospitalisation continues, despite spread in the community, then the public health crisis is over.

“And so far, up to Delta, we’re in a very good position, as long as we’ve got people vaccinated.”

Sir Andrew said rates of vaccine effectiveness will get lower against symptomatic illness over time, but the focus should be on hospital admissions.

“What the virus is doing is it’s evolving away from immunity, and we’re seeing lower effectiveness against symptomatic infection,” he said.

“If we wind the clock forward to a year or two from now, one would expect those numbers to get lower and lower, because unless the virus disappears from the planet, which I don’t think is going to happen, it will have to be able to survive in vaccinated populations.

“If we focus on effectiveness against symptomatic disease in the future, we’ll go mad because those numbers will get lower and lower over time because that is the only way the virus survives.

“So the really important question is: What does effectiveness against hospitalisation look like?”

Sir Andrew said there was still uncertainty about how future variants will behave, but suggested that the regular tweaking of vaccines is not “achievable”.

He told MPs: “If the aim is to try and stop transmission, and to stop symptomatic infection then I think there is no doubt that a tweaked vaccine would do that.

“The problem is that if we tweaked one, for example now for the Delta variant, we may well have the Omega variant or the Epsilon variant, or the Kappa variant, and you would have to then potentially be tweaking the vaccines very regularly.

“And I just don’t think that is going to be achievable during this period where there’s so much transmission going on around the world and new variants are going to be thrown up.

“That may be something that if we get into a more stable situation in the future, where there is one dominant variant each year where you might have an annual update, if indeed we need to do that – at this moment, we still have very high levels of protection against hospitalisation, even with the original version of the vaccines.

“So whether we need to have those new variant (vaccines to prevent) hospitalisation is something which is not yet clear.”

Regarding boosters in the autumn, Sir Andrew said “we have absolutely no evidence that there is a need for a third dose” at the moment, “particularly when you consider that we’ve got very high levels of protection against hospitalisation with two doses”.

He added: “So the reason why you might look at a third dose is if that protection was waning. And so far we don’t have evidence that’s the case, it’s just too early to do that.”

Dr Susan Hopkins, strategic response director for Covid-19 at Public Health England (PHE), told MPs that the pandemic would not end “until the whole world has had an ability to get vaccinated.”

She continued: “And that realistically is two years away.

“And until that, where we get some level of control over everything, we will continue to see variants emerge, we will continue to run behind as we try and understand this, and we will get to a position of stability, where we are with… seasonal influenza.

“So we have some time to go. And the world will need to be vaccinated before we get to a stable situation.”

She said that the odds of transmission within a household for the Delta variant first identified in India was 66% higher than for the Alpha variant first identified in Kent.

Dr Hopkins said if the Delta variant was “unmitigated” and left to spread without any measures, the reproduction number (the R value) could be “greater than five and maybe up to seven”.

She added: “That’s why we need people to have vaccination because that’s a clear mitigation measure, that’s why we need people to take care, take caution, particularly in healthcare settings.”

Dr Hopkins also told the committee that PHE estimates that 15,000 to 25,000 new infections are taking place each day in the UK.

She added: “It doesn’t take very many doublings to get to very large numbers.

“But what we won’t see – or what we hope we won’t see and I think we won’t see because of vaccine – is the same numbers of hospitalisations.

“So we will have a much much greater amount of infection in the community without seeing the same impact of hospitalisations.”

But she suggested that if case numbers get too high, the numbers in hospital could rise substantially, and so measures were needed right now to hold that peak down while vaccines were given.

Regarding what may happen after the July 19 date set by the Government for lifting remaining restrictions in England, Dr Hopkins said there will be more emphasis on personal risk and responsibility.

She added: “I think we will all need to make decisions for ourselves, particularly on wearing masks, using better ventilation, hand hygiene.”

The senior medic said some countries have relied on social responsibility whereas others have legislated, adding: “I think there’s a middle road, as we have vaccination heavily rolled out, that requires potentially in some areas where there’s higher risk – for example, transport and for those of us who pack ourselves into the Tube regularly, we may feel more comfortable if everyone else was asked to wear a mask as well for those very close encounters for potentially periods longer than 15 minutes.

“But in the more general societal areas, such as shops, I think it is going to come down to personal opinions and responsibilities, rather than legislation for the longer term.”