Scientists remain divided over UK plans for Covid booster jabs

Scientists remain divided over whether Covid booster jabs will be needed in the UK, as health officials and the NHS continue preparations to administer a third dose to 30 million people later this year.

The Joint Committee on Vaccination and Immunisation advised ministers in June to start planning for the roll out of third doses ahead of a feared winter wave, with a number of priority groups - including healthcare workers, the clinically vulnerable and care home residents - set to be inoculated once again from next month.

But amid limited evidence on the need for immunological ‘top-ups’, along with stuttering vaccination rates in the world’s poorest countries, some experts have suggested that the UK should hold off on its booster programme.

“There isn’t evidence yet of imperfect vaccines leading to significant severe disease that would be overcome by boosters,” said Al Edwards, an associate professor in biomedical technology at the University of Reading.

“At the same time, so many populations across the world are short of first and second doses. It’s morally wrong to use manufacturing capacity to provide boosters in the UK.”

The World Health Organisation (WHO) last week called for a global moratorium on booster shots until at least the end of September to ensure precious vaccine supplies are diverted to poorer countries more in need.

Just 1.1 per cent of people in low-income countries have received one vaccine dose, compared with 53.9 per cent in high-income nations, according to analysis by the House of Commons Library.

The UK government’s own scientific advisers have also urged ministers to take more action in supporting international vaccination efforts to prevent the future emergence of variants.

Allyson Pollock, a clinical professor of public health at the University of Newcastle, said that 90 per cent of the adult population in Britain have antibodies and that reinfections are “very low” and “generally mild”.

“Therefore why at this stage is the government wanting to give booster doses, instead of re-allocating the vaccines it’s stockpiled?”

Even after offering vaccines to over-16s and booster jabs to higher-risk adults, it’s estimated the UK will have 210 million leftover doses by the end of the year – though the government has committed to sending 100 million shots overseas by June 2022.

However, some experts have highlighted that many of the UK’s stockpiled doses will be Pfizer, which must be transported and stored in sub-zero temperatures – a requirement that many of the world’s poorest nations cannot meet.

“The problem with the WHO’s proposed moratorium is that we could have a billion doses sitting in the UK and it’s totally useless for most low-income countries because they cannot store it,” said Professor Keith Neal, an epidemiologist at the University of Nottingham.

Professor Eleanor Riley, an immunologist at the University of Edinburgh, said there was a “political” decision to be made if the bulk of the UK’s surplus supplies cannot be readily shipped abroad due to logistical challenges.

“If we’ve got Pfizer vaccines sitting around, not being used that can’t be sent overseas for whatever reasons, then there’s no harm in giving a booster to the people who had the vaccines right at the beginning [of the national rollout],” she said.

However, Prof Riley said it was unclear whether booster jabs are even needed given the effectiveness of two vaccine doses in reducing the risk of hospitalisation and death.

Although research suggests that antibody levels may wane with time, other components of the immune system, such as T cells, will help to maintain long-lasting protection that keeps people out of hospital.

“I’m not sure I’ve seen any data yet that says we need boosters to keep people out of hospital,” said Prof Riley.

More research is needed on whether people who were vaccinated back in December and January are now ending up in hospital with the highly-transmissible Delta variant, she added. “That could imply that maybe the vaccine is wearing off. But remember: those people who got the vaccines earliest on were the most vulnerable anyway.”

If cases are rising in these groups, that shouldn’t necessarily be seen as confirmation that the vaccines don’t work in providing long-term protection for the majority of people, Prof Riley said.

On the basis of the current immunological evidence and widening global inequalities, Dr Peter English, a former chair of the BMA Public Health Medicine Committee, said the government should “hold off for the moment.”

“The question of do we need boosters because of waning antibody levels, you can’t tell at the moment. They are only a small part of the story,” he said. “And there doesn’t seem to be any epidemiological evidence that reinfections are causing a huge problem.”

However, experts have acknowledged there is a risk in waiting a few more months for clearer data to confirm whether a booster programme is needed – by which point infections may have surged once again among those with fading immunity.

“There is a good argument for doing boosters, as we simply do not know – and by the time we do know for sure, we could be in a mess,” said Prof Neal.

Should the UK press ahead with its booster programme, this will place further strain on health services at a time when they are attempting to refocus their resources on patients who were neglected throughout the lockdowns, said Prof Pollock.

“When you do booster doses, it’s not just the vaccines you’re using. You’re also using scarce GP and public health resources to administer and monitor these jabs. So we really need to see a proper cost-benefit analysis as to why we’re doing it.”