Danny Altmann, Professor of Immunology at Imperial College London
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Danny Altmann, Professor of Immunology at Imperial College London
In a piece in the Guardian this weekend headed "Where's the herd immunity? Our research shows why Covid is still wreaking havoc", Danny Altmann, Professor of Immunology at Imperial College London, writes that "contrary to the myth that we are sliding into a comfortable evolutionary relationship with a common-cold-like, friendly virus, this is more like being trapped on a rollercoaster in a horror film". I will quote it at length so you get a full sense of the pessimistic vision he is setting out.
We are all so very tired of COVID-19, and there are many other crises to wrestle with. This pandemic has been going on since the beginning of 2020, and a state of hypervigilance can only be maintained for so long. And yet, 'just live with it' looks self-evidently too thin a recipe and, currently, not very workable or successful with the emergence of BA.4 and BA.5 Omicron subvariants.

According to the latest numbers, released today, the U.K. added more than half a million new Covid infections in the past week, and the estimated number of people with Covid in total was somewhere between 3% and 4% of the population.

Many have been rather unwell and off work or school, with the associated disruptions to education, healthcare and other vital services. These infections will also inevitably add to the toll of long Covid cases. According to ONS data, the supposedly 'mild' waves of Omicron during 2022 have brought more than 619,000 new long Covid cases into the clinical caseload, promising an enduring and miserable legacy from this latest phase.

Rather than a wall of immunity arising from vaccinations and previous infections, we are seeing wave after wave of new cases and a rapidly growing burden of long-term disease. What's going on? The latest scientific research has some answers.

During May and June two new variants, BA.4 and BA.5, progressively displaced the previous Omicron subvariant, BA.2. They are even more transmissible and more immune-evasive. Last week a group of collaborators, including me and a professor of immunology and respiratory medicine, Rosemary Boyton, published a paper in Science, looking comprehensively at immunity to the Omicron family, both in triple-vaccinated people and also in those who then suffered breakthrough infections during the Omicron wave. This lets us examine whether Omicron was, as some hoped, a benign natural booster of our Covid immunity. It turns out that isn't the case.

We considered many facets of immunity, including the antibodies most implicated in protection ('neutralising antibodies'), as well as protective 'immune memory' in white blood cells. The results tell us it is unsurprising that breakthrough infections were so common. Most people - even when triple-vaccinated - had 20 times less neutralising antibody response against Omicron than against the initial 'Wuhan' strain. Importantly, Omicron infection was a poor booster of immunity to further Omicron infections. It is a kind of stealth virus that gets in under the radar without doing too much to alert immune defences. Even having had Omicron, we're not well protected from further infections.

Also, to be added to the now complex mix is 'immune imprinting'. This is the finding that our immune response to Covid is shaped very differently, depending on our prior exposures - infection in one wave relative to another, plus vaccination. In our study, those who'd been infected in the first wave and then again with Omicron had particularly poor T-cell responses and no boosting of antibodies. That is, some combinations of exposures may leave us poorly protected relative to others.

Contrary to the myth that we are sliding into a comfortable evolutionary relationship with a common-cold-like, friendly virus, this is more like being trapped on a rollercoaster in a horror film. There's nothing cold-like or friendly about a large part of the workforce needing significant absences from work, feeling awful and sometimes getting reinfected over and over again, just weeks apart. And that's before the risk of long Covid. While we now know that the risk of long Covid is somewhat reduced in those who become infected after vaccination, and also less in those from the Omicron than the Delta wave, the absolute numbers are nevertheless worrying.
Meanwhile, Australia is mulling bringing back mask mandates as it faces a resurgent flu during its winter alongside an Omicron BA.4-5 wave, which despite vaccination and the mildness of Omicron is causing a relatively high number of deaths.

In fact, though, contrary to Prof. Altmann's claim, the Imperial study he refers to did show an immune response from infection against Omicron - though not one from the vaccines - and real-world evidence from Qatar suggests that natural immunity provides protection of about 50% against Omicron for at least a year (whereas the vaccines seem to increase the risk of infection within a few months). There's also no evidence that vaccines prevent Long Covid, with one recent large U.S. study finding "no significant difference in the risk of... any long-Covid feature".

Prof. Altmann himself sees little value in further boosters, writing:
Even if we had good vaccination coverage, we have entered a period of diminishing returns. A study reported in the BMJ last week showed us that the protection gained from a fourth booster dose likely wanes even faster than previous boosters. This leaves us between a rock and a hard place: continue to offer suboptimal boosters to a population who seem to have lost faith or interest in taking them up, or do nothing and cross our fingers that residual immunity might somehow keep a lid on hospitalisations (as happened in South Africa and Portugal).
It doesn't seem to occur to him that Portugal and South Africa's experience shows why his pessimism is misplaced, and that we actually are developing immunity against the virus.

The U.K. has had very few excess deaths from Covid since Omicron arrived, though plenty from other causes. Nonetheless, some it seems have no intention of letting this go.