Vaccine dilemma: scientists push for summer booster as Covid-19 surge hits Europe

Spiralling case numbers raise fears of diminished protection against new coronavirus variants

Spiralling case numbers have raised fears of diminished protection against new coronavirus variants. Photo: PA

With Covid-19 case numbers across Europe surging, experts are predicting a new race that they'd hoped to postpone: another round of booster vaccinations to counter the next wave of the disease as the cooler months approach.

The subvariants of Omicron have so far been milder but far more contagious than earlier mutations, leading to increasing rates of infections and hospital admissions. Case numbers have tripled in the past four weeks.

Professor Danny Altmann, of Imperial College London, told The National that a fourth dose ― constituting a second booster after the first two shots ― towards the end of summer would help slow the pace of transmission in what are the traditional seasonal peaks of autumn/winter in temperate climates.

But, even then, he fears boosters would not be enough, arguing that a “next generation” of vaccines was now desperately required.

“Many in the UK would consider that we’re in a serious BA.5 [Omicron variant] wave,” Prof Altmann said.

“We are a population with waned antibody levels and rather poor cross protection against this variant, and we seem to have settled for 50,000 to 70,000 excess deaths per year.

“So we are not living with it very well. A fourth dose late summer would certainly help, although the strategy is starting to offer diminishing returns. We need the next generation of vaccines.”

Vaccine immunity can wane after three months

Immunity begins to fall between three and six months after each shot, and there are concerns about continuing efficacy given that presently available vaccines were designed to target the original Wuhan virus rather than the new variants.

Omicron subvariant BA.5 is spreading across Europe, with the 53 countries in the WHO European region currently registering about 500,000 cases daily, up from about 150,000 cases a day at the end of May.

"As countries across the European region have lifted the social measures that were previously in place, the virus will transmit at high levels over the summer," WHO Europe regional director Hans Kluge said.

"This virus won't go away just because countries stop looking for it. It's still spreading, it's still changing, and it's still taking lives."

There are currently around 500 deaths per day across Europe - the same level as that recorded not long after the start of the pandemic during the summer of 2020 when countries were in lockdown.

Officials are concerned because though Omicron is milder it is far more transmissible than the strain prevalent two years ago, and the colder weather in which coronavirus thrives is looming.

The past two winters have seen daily death rates rise to up to 5,000 due to seasonal spikes, prompting fears that urgent action needs to happen sooner rather than later.

Should fourth doses be offered to everyone?

Australian health authorities this week recommended that a fourth Covid-19 injection be made available to anyone aged over 30, with a special recommendation for those aged 50-plus to take up the offer.

The UK government’s independent vaccine advisory group, the Joint Committee on Vaccination and Immunisation (JCVI), has recommended that the NHS and care homes prepare for an autumn booster campaign, likely to start in September. In the UK, fourth doses are given only to the over 70s and the most vulnerable.

Dr Stephen Griffin, a virologist at the University of Leeds, says the UK is “ignoring” the warning signs and not preparing for the next big wave.

“What needs to be done and what is being done are two different things,” Dr Griffin told The National.

“The government doesn’t seem minded to push forward vaccines. They have only mentioned boosters for the over-70s in the autumn. It is very clear it is a ‘living with Covid’ strategy.

“We are not in a stable state to say vaccines will give a nominal level of protection now we have got a third wave. To say the pandemic is over, it clearly is not the case. We cannot possibly sustain these new waves of infection. It is still as dangerous with hospital admissions and deaths racking up very quickly as prevalence increases.

“It really is quite difficult to understand. We have not really heard anything from government [about its plans]. We have heard about keeping masks on in hospitals again ― which is a policy that never should have been dropped.

“It appears to be 'let’s ignore it' instead of tackling it. We know enough now not to have to swing between the pendulum of harsh restrictions and opening up."

Dr Griffin wants to see more refined vaccines given more often and warns that Omicron is dangerous. There have, he says, been three waves in the past six months, with the latest "pretty devastating" one responsible for 1,000 hospital admissions a day.

“There are signs this variant can be more nasty and we have to look after our whole population. Omicron has killed more people in the UK than Delta," he said.

“We know this virus is incredibly infectious. Antibodies can drop after three to six months. The answer is to give more vaccines more often at a time when they are waning and when the virus is coming and to pre-empt a new wave, but this is hard to do when new waves are coming every few months.”

Fourth dose boosts immunity more effectively than third dose

Research in the UK shows that a fourth Covid-19 dose increases antibodies to a higher level than that of a third shot.

“These results underline the benefits of the most vulnerable people receiving current [second] boosters and gives confidence for any prospective autumn booster programme in the UK, if the JCVI considers it is needed at that time,” said the director of the NIHR Southampton Clinical Research Facility, Professor Saul Faust, who led the research.

“We knew that it was important to offer a fourth dose to those most vulnerable earlier in the year,” said Professor Andrew Ustianowski, NIHR clinical lead for the Covid-19 vaccination programme and joint national infection specialty lead.

“These new study findings support that decision and provide the public with the confidence that fourth doses are both safe and even more effective than third doses at boosting immunity against Covid-19."

The team is also investigating the optimal interval between second and third doses of vaccines.

Do we need Omicron-specific vaccines?

Prof Faust told The National he is now conducting a study this summer on a vaccine that targets Omicron.

“The UK has already announced plans to look at bivalent boosters and the Cov-boost trial will also be testing the Moderna bivalent vaccine compared to the original Pfizer vaccine in a small sub-study this summer,” he said.

Last week, US regulators recommended changing the design of the vaccines to produce a new booster specifically capable of countering Omicron.

Of the discussions in the US, Prof Altmann pointed out that the immunology was very complex. "Decisions need to be evidence and clinical-trial based, not decided by commercial interests,” he said.

In the UK, Pfizer and Moderna have tweaked their vaccines for Omicron and their trial data is waiting approval from the UK’s Medicines and Healthcare products Regulatory Agency.

The agency needs to assess the safety, quality and effectiveness of the modified shots before the JCVI can consider whether to offer the vaccines in the autumn booster programme.

Dr Griffin believes that by the time any trials have been completed and approved, another variant will already have overtaken its predecessors.

“The US is looking at an Omicron vaccine but the problem is things are moving so quickly we will miss the boat by the time the trials are done. With the boosters, you have to wonder which winter we are actually preparing for,” he said.

“Is there much to gain from an Omicron vaccine, because it doesn’t give protection against anything other than itself. Last year, it was the Delta threat, then along comes Omicron. Who knows where we will be next?

“We have already had three different waves in the last six months. It’s a cat-and-mouse game.”

Many scientists argue that even though the vaccines are not necessarily effective at preventing Omicron infections, they still reduce the risk of severe disease.

With Omicron accounting for more than half of all new UK Covid-19 cases, Prof Susan Hopkins, the chief medical adviser at the UK Health Security Agency, has renewed calls for people eligible for a fourth injection to come forward.

"Our data shows that 17.5 per cent of people aged 75 years and over have not had a vaccine within the past six months, putting them more at risk of severe disease. We urge these people in particular to get up to date."

Given that about 1,000 patients are being admitted to hospital each day with coronavirus, the JCVI has announced a reintroduction of mandatory mask-wearing in hospitals.

It comes just weeks after the mandatory provisions were dropped on June 10.

But with no urgent warnings from the government, Dr Griffin fears that the measure will make little difference, and he has little faith in the ability of the newly appointed health secretary, Steven Barclay, to address the situation.

“If the government says something important, people tend to listen. It’s crazy how many people are so blase, saying they do not need masks, tests or to isolate," he said. "When did this virus stop being what it is?

“There are signs this variant can be more nasty and we have to look after our whole population. It is the responsibility of the government and public health officials. We have no safety net for Covid-19 now. Vaccines are great but not foolproof or infallible and will not see us through this. It is really worrying.

“We are just not doing enough. They are sticking their fingers in their ears and singing 'la-la-la'," he said. "Everyone needs to start planning.”