Courtesy The Times (UK)

Science offers hope despite fears  about the effect of quick-spreading coronavirus variants

Borders closed, lockdowns were tightened and dire warnings of aggressive new outbreaks were issued. Scientists worried about the vulnerability of children and politicians agonised over shutting schools.

There was scant relief on the coronavirus front last week, as the discovery of an alarming pair of mutant strains played havoc with the Christmas plans — not to mention the fraying nerves — of Britons, South Africans and a rapidly growing number of other nationalities.

Yet a singular effort by a weary microbiologist in Texas offered at least a glimpse of hope that the mutant army of variant coronavirus strains will ultimately be defeated by science.

Of the many questions raised by the separate but similarly menacing Covid-19 variants first identified in southeast England and South Africa’s Eastern Cape province, the most worrying in the longer term was surely their impact on the hi-tech vaccines that are already being pumped into arms around the world.

Will the immunising effects of the medical marvels developed by Pfizer, Moderna and AstraZeneca be neutered by a malevolent shift in the virus’s angle of attack? Are we back to square one on vaccine development? How long must we endure the uncertainty of not knowing how effective and/or durable these or any other vaccines may prove?

At his Texas University laboratory in Galveston, Professor Vineet Menachery specialises in the shifting relationships between coronavirus infections and the immunity systems they confront. How does disease spread in the body, and why is the severity of symptoms so varied? What works and what does not in preventing infection and limiting its effects?

Menachery was already familiar with the most worrying of the 23 mutations identified by UK scientists in the new Covid variant, formally labelled VUI-202012/01 — a variant under investigation”. The new threat to British health spread so fast through London, it was estimated to account for almost two-thirds of all new cases in the capital at the time of its discovery. One of its mutations, labelled N501Y, has also been identified in the South African variant, which rapidly became the dominant strain in the Eastern and Western Cape provinces around Port Elizabeth and Cape Town.

The N501Y mutation occurs in the virus’s spike protein, a key transmission agent that binds itself to human cells via receptors in the respiratory system. Scientists on several continents are still battling to understand to what extent, and in what combination with other factors, N501Y accelerates transmission, makes patients sicker or helps the virus dodge the body’s immune defences.

Menachery swiftly set up a test with two variants — one containing the N501Y mutation and one without it. Bingo. Using antibodies taken from Covid patients who had recovered from the disease, Menachery found no serious difference in the combative powers of the human immune system, whichever of the two variants it faced.

The antibodies proved just as good at neutralising virus with the mutation as without it”, he wrote in a summary of his findings last week. Vaccine manufacturers quickly chimed in with assurances their products could easily be tweaked to counter any dangerous mutations — just as the flu vaccine is modified each year to combat continuous variations in the virus.

In layman’s terms, there appears no need for panic: the longer-term vaccine outlook remains bright. It is the short term that still looks grim. Millions of middle-aged and younger Britons will have to survive the rest of winter before they can join the queue for jabs.

The price of good science
When a panel of 21 global health experts from 13 countries examined the world’s preparedness for outbreaks of infectious disease last year, it painted a glowing picture of British medical and scientific capabilities. The UK was deemed the most advanced of 195 countries in its laboratory research capacity, its real-time surveillance and reporting of disease and its commitment to the sharing of genetic and biological data and specimens”.

Those assets are paying off, big time. Whatever one thinks of the UK’s handling of the first 11 months of the coronavirus crisis, its technical expertise in monitoring virus behaviour and analysing its shifting genomic structures remains unmatched. Last week several American scientists lamented what the leading virologist Angela Rasmussen described as the woeful state of genomic surveillance in the US”.

Yet the price of advanced scientific understanding has been last-minute political chaos, with Christmas wrecked for millions of Britons and a radical revision of the government’s pandemic strategies in progress. If it was good news that vaccines are likely to remain effective against a mutating virus, the bad news was that months of misery may still lie ahead.

The latest revision of the government’s ever more complicated tier system of regional containment was sparked by a statistical anomaly. In late November the virus appeared under control in much of the UK, but caseloads were increasing markedly in the southeast.

Was everyone out partying? Failing to wear masks? Further investigation identified a variant strain in an unidentified patient in Kent. Tracing the genetic evidence backwards, researchers concluded that the new variant had emerged in September. On December 14, Matt Hancock, the health secretary, announced that the variant was responsible for 1,000 new cases in the southeast and was spreading faster than any other strain of the virus.

The search for patient zero
It remains unclear exactly how the variant developed. The search for patient zero — the strain’s first victim — continues, but numerous experts have speculated that he or she was someone with a compromised immune system who endured a long battle with the virus. It is not uncommon for viruses to mutate more rapidly if they remain in a patient’s system for long periods.

There is little evidence the variant is causing more severe illness, and it may not be until the new year that scientists have a clearer idea of the implications for treatment and care. Yet the government is worried by evidence that the variant is spreading more quickly than previous forms of the virus. Estimates of the increase in transmission rates vary from 40% to 70%. Adam Kucharski of the London School of Hygiene & Tropical Medicine said last week: If multiple data sources point towards substantially increased transmission, it suggests we have [a] big problem.”

There are also fears the new variant produces a heavier viral load, which may increase transmission rates and the severity of symptoms. One British study found last week that the variant has higher viral loads in Kent than in Greater London, though David Bonsall of the Nuffield Department of Medicine at Oxford University suggested that the different average ages of the two sample groups may partly explain the difference.

Most troublesome of all for the government was the suggestion that the new variant is more of a threat to children than previous strains. Boris Johnson is already under pressure to decide whether schools should resume on schedule in the new year.

Disease detectives at work
Complicating all this was the emergence of South Africa’s new strain, with the accompanied likelihood that further more aggressive mutations may emerge elsewhere — notably in America, where the arrival of a new administration may unleash the long-caged capabilities of the Centres for Disease Control, a bête noire for Donald Trump. The UK has used genomics throughout this pandemic and thus was well placed to identify the new variant early in its rise,” noted Professor Jonathan Ball of Nottingham University. In other countries that do not have this capacity it is quite possible that these variants are already in circulation, but currently unidentified.

It appears we are entering a particularly dangerous phase of this pandemic, making the effective rollout of the vaccines even more time-critical.”

Professor Lawrence Young of Warwick Medical School warned that, pending wider availability of vaccines, the move to harsher levels of restriction across the country is inevitable. It is essential that we do everything possible to prevent the South African variant from spreading to the UK population.”

There was something of a competition among scientists last week to find analogies for the mind-numbingly complex processes involved in virus research. Best of all was the description of virus researchers as disease detectives”, peering at the virus’s crown of spikes, continually searching for evidence to close the case on a brutal pandemic.

One of those detectives last week was Menachery. In normal times there is a drawn-out process for scientific studies involving peer review of findings and publication in medical journals. It might have taken weeks, if not months, for the Texas microbiologist to formulate a report and publish it. But these are not normal times.

I would prefer this in a manuscript,” he wrote of his variant study, but given the time of year and that I’m tired, I’ll just tweet the data.” It was 21st-century science via Twitter, not generally considered an orthodox pathway, but an online community of professional disease detectives were mostly thrilled with his findings. Can somebody buy the man a drink please?” tweeted Professor Florian Krammer, a prominent New York microbiologist.