Analysis: Booster jabs are coming – but are they really needed?

There are growing signals that suggest the ability of the vaccines to protect against infection is waning, yet they continue to remain effective in keeping people out of hospital. By Samuel Lovett

(Getty Images)

It’s a question that scientists have spent weeks trying to answer: are booster jabs really needed? As it stands, there is much talk and speculation – but still no real clarity to swing the debate firmly one way or another.

There are certainly growing signals that suggest the ability of the vaccines to protect against infection and mild symptomatic disease is waning. Numerous reports from across the globe point to this.

There is also the growing belief that vaccinated people infected with the Delta variant carry as much virus as the unvaccinated, making it likely that they are infectious and can spread the pathogen to others.

What should not be forgotten is that vaccination makes it far less likely to catch Covid-19 in the first place – yet the possibility of reinfection has nonetheless shattered all hope of herd immunity and the fallacy that the vaccines are our only way out of this crisis.

We’re told that antibody levels are falling, that “breakthrough infections” are on the rise, that Delta may or may not be to blame for the diminished effectiveness of the vaccines, that protection even against severe disease is now dwindling for older people.

These are all valid concerns and, in some countries, it has been enough to push health officials in the direction of a third “booster” dose.

Especially for the elderly, clinically vulnerable, immunocompromised, and anyone who is unable to mount a proper response after vaccination, a third jab makes sense. Science tells us that these individuals will be among the first to suffer the consequences of dwindling immunity.

Ahead of what is likely to be a difficult winter, it’s a hard argument to make that we shouldn’t be using the tools available to us to best protect those most at risk.

Many scientists have stressed that we won’t fully know if boosters are needed until it’s too late, when infections are rising and vaccinated people with the disease need to be hospitalised. “We don’t have the data but by the time we do have it, we could end up with egg on our face,” says Professor Eleanor Riley, an immunologist at Edinburgh University.

In Israel, there are faint indications that for those aged 65 or older who got their second Pfizer doses in January, the vaccine is no longer as effective as it once was in protecting against severe disease – though the data have a wide margin of error, researchers say, making it difficult to draw clear conclusions.

For now, there is no red flag to suggest that the vaccines aren’t keeping the vast majority of vaccinated people out of Covid wards or ICUs.

Of course, as more of the population becomes double-jabbed, we will see a higher relative percentage of vaccinated people in hospital, but this should not be misinterpreted as proof of waning protection against serious illness.

Many experts therefore believe that boosters should only be warranted if the vaccines, which have prevented tens of thousands of deaths so far, likely more, do start to fail in preventing Covid hospitalisations.

Dr Céline Gounder, an infectious disease specialist and member of the US Covid-19 advisory board to the White House, told the New York Times that “feeling sick like a dog and laid up in bed, but not in the hospital with severe Covid, is not a good enough reason” for administering third doses.

More focus should be placed on delivering jabs to those who remain unvaccinated across the world, she added, with infections continuing to surge in some of the poorest countries and the spectre of a new and dangerous variant looming just around the corner.

The World Health Organisation has vocalised the greatest opposition to the concept of booster jabs. “We’re planning to hand out extra life jackets to people who already have life jackets, while we’re leaving other people to drown without a single life jacket,” Dr Michael Ryan, the WHO’s emergencies chief, said this week.

In the UK, the many caveats and complexities to the debate continue to be scrutinised by the Joint Committee on Vaccination and Immunisation (JCVI). The group met on Thursday to discuss a potential booster campaign and determine which people might “really need” another jab.

Having initially indicated that all over-50s will be offered a third dose in the months ahead, the JCVI has since suggested that the autumn programme may not be as broad as envisioned.

“I think at this point we need to focus on individuals who are more likely … to get sick again if they’ve not got a booster,” said committee member Professor Adam Finn, adding that there is “enough evidence” to show that there are people who “are very unlikely to be well protected by those first two doses”.

Nonetheless, he added, “We do need more evidence before we can make a firm decision on a much broader booster programme.”

Despite criticism, the US and Israel have already broken rank in offering third doses. The UK will be next to follow. Amid stuttering vaccination rates across the world, it’s a controversial path to tread – one that certainly has its benefits, but also comes with consequences for those waiting for a first jab, let alone a third.