Chris Murray, a University of Washington disease expert whose projections on COVID-19 infections and deaths are closely followed worldwide, is changing his assumptions about the course of the pandemic.
Murray had until recently been hopeful that the discovery of several effective vaccines could help countries achieve herd immunity, or nearly eliminate transmission through a combination of inoculation and previous infection.
But in the last month, data from a vaccine trial in South Africa showed not only that a rapidly-spreading coronavirus variant could dampen the effect of the vaccine, it could also evade natural immunity in people who had been previously infected.
‘I couldn’t sleep’ after seeing the data, Murray, director of the Seattle-based Institute for Health Metrics and Evaluation, told Reuters.
‘When will it end?’ he asked himself, referring to the pandemic. He is currently updating his model to account for variants’ ability to escape natural immunity and expects to provide new projections as early as this week.
A new consensus is emerging among scientists, according to Reuters interviews with 18 specialists who closely track the pandemic or are working to curb its impact.
Many described how the breakthrough late last year of two vaccines with around 95% efficacy against COVID-19 had initially sparked hope that the virus could be largely contained, similar to the way measles has been.
Scientists have told Reuters news agency that data in recent weeks on new variants from South Africa and Brazil has undercut that optimism felt in the scientific community following the success of the vaccines
But, they say, data in recent weeks on new variants from South Africa and Brazil has undercut that optimism. They now believe that SARS-CoV-2 will not only remain with us as an endemic virus, continuing to circulate in communities, but will likely cause a significant burden of illness and death for years to come.
As a result, the scientists said, people could expect to continue to take measures such as routine mask-wearing and avoiding crowded places during COVID-19 surges, especially for people at high risk.
Even after vaccination, ‘I still would want to wear a mask if there was a variant out there,’ Dr. Anthony Fauci, chief medical advisor to U.S. President Joe Biden, said in an interview.
‘All you need is one little flick of a variant (sparking) another surge, and there goes your prediction’ about when life gets back to normal.
Some scientists, including Murray, acknowledge that the outlook could improve. The new vaccines, which have been developed at record speed, still appear to prevent hospitalisations and death even when new variants are the cause of infection.
Many vaccine developers are working on booster shots and new inoculations that could preserve a high level of efficacy against the variants. And, scientists say there is still much to be learned about the immune system’s ability to combat the virus.
Already, COVID-19 infection rates have declined in many countries since the start of 2021, with some dramatic reductions in severe illness and hospitalisations among the first groups of people to be vaccinated.
Murray said if the South African variant, or similar mutants, continue to spread rapidly, the number of COVID-19 cases resulting in hospitalisation or death this coming winter could be four times higher than the flu. The rough estimate assumes a 65% effective vaccine given to half of a country’s population.
In a worst-case scenario, that could represent as many as 200,000 U.S. deaths related to COVID-19 over the winter period, based on federal government estimates of annual flu fatalities.
His institute’s current forecast, which runs until June 1, assumes there will be an additional 62,000 U.S. deaths and 690,000 global deaths from COVID-19 by that point. The model includes assumptions about vaccination rates as well as the transmissibility of the South African and Brazilian variants.
The shift in thinking among scientists has influenced more cautious government statements about when the pandemic will end.
Britain last week said it expects a slow emergence from one of the world’s strictest lockdowns, despite having one of the fastest vaccination drives.
U.S. government predictions of a return to a more normal lifestyle have been repeatedly pushed back, most recently from late summer to Christmas, and then to March 2022.
Israel issued ‘Green Pass’ immunity documents to people who have recovered from COVID-19 or been vaccinated, allowing them back into hotels or theatres. The documents are only valid for six months because it’s not clear how long immunity will last.
‘What does it mean to be past the emergency phase of this pandemic?,’ said Stefan Baral, an epidemiologist at the Johns Hopkins School of Public Health.
While some experts have asked whether countries could completely eradicate any case of COVID-19 through vaccines and stringent lockdowns, Baral sees the goals as more modest, but still meaningful.
‘In my mind, it’s that hospitals aren’t full, the ICUs aren’t full, and people aren’t tragically passing,’ he said.
Israel has issued ‘Green Pass’ immunity documents (pictured) to people who have recovered from COVID-19 or been vaccinated, allowing them back into hotels or theatres
The documents are only valid for six months because it’s not clear how long immunity will last. Pictured: People attend a show at the Khan Theatre in Jerusalem on February 23
From the beginning, the new coronavirus has been a moving target.
Early in the pandemic, leading scientists warned that the virus could become endemic and ‘may never go away,’ including Dr. Michael Ryan, head of the World Health Organization’s emergencies programme.
Yet they had much to learn, including whether it would be possible to develop a vaccine against the virus and how quickly it would mutate.
Would it be more like measles, which can be kept almost entirely at bay in communities with high rates of inoculation, or flu, which infects millions globally each year?
For much of 2020, many scientists were surprised and reassured that the coronavirus had not changed significantly enough to become more transmissible, or deadly.
A major breakthrough came in November. Pfizer Inc and its German partner BioNTech SE as well as Moderna Inc said their vaccines were around 95 percent effective at preventing COVID-19 in clinical trials, an efficacy rate that is much higher than any flu shot.
Scientists said they were pleasantly surprised by how effective the ‘first generation’ of vaccines had been at curtailing the effects of Covid-19. Pictured: A medical worker prepares the Pfizer vaccine at a quarantine hotel in Perth, Australia on February 22
At least a few of the scientists Reuters interviewed said even in the wake of those results, they hadn’t expected the vaccines to wipe out the virus.
But many told Reuters that the data raised hope within the scientific community that it would be possible to virtually eliminate COVID-19, if only the world could be vaccinated quickly enough.
‘We all felt quite optimistic before Christmas with those first vaccines,’ said Azra Ghani, chair in infectious disease epidemiology at Imperial College London. ‘We didn’t necessarily expect such high-efficacy vaccines to be possible in that first generation.’
The optimism proved short-lived. In late December, the UK warned of a new, more transmissible variant that was quickly becoming the dominant form of the coronavirus in the country.
New variants of Covid-19 heralded a ‘new chapter’ in the world’s fight against the virus, one vaccine specialist said. Pictured: A man receives a dose of China’s Sinovac vaccine in Sibate, Colombia on February 24
Around the same time, researchers learned of the impact of the faster-spreading variants in South Africa and in Brazil.
Phil Dormitzer, a top vaccine scientist at Pfizer, told Reuters in November that the U.S. drugmaker’s vaccine success signalled the virus was ‘vulnerable to immunisation’ in what he called ‘a breakthrough for humanity.’
By early January, he acknowledged the variants heralded ‘a new chapter’ in which companies will have to constantly monitor for mutations that could dampen the effect of vaccines.
In late January, the impact on vaccines became even clearer. Novavax’s clinical trial data showed its vaccine was 89 percent effective in a UK trial, but just 50 percent effective at preventing COVID-19 in South Africa. That was followed a week later by data showing the AstraZeneca PLC vaccine offered only limited protection from mild disease against the South African variant.
The most recent change of heart was considerable, several of the scientists told Reuters.
Shane Crotty, a virologist at the La Jolla Institute for Immunology in San Diego, described it as ‘scientific whiplash’: In December, he had believed it was plausible to achieve so-called ‘functional eradication’ of the coronavirus, similar to measles.
Now, ‘getting as many people vaccinated as possible is still the same answer and the same path forward as it was on December 1 or January 1,’ Crotty said, ‘but the expected outcome isn’t the same.’
WHY ARE SCIENTISTS SCARED OF THE SOUTH AFRICAN VARIANT?
Real name: B.1.351
When and where was it discovered?
Scientists first noticed in December 2020 that the variant, named B.1.351, was genetically different in a way that could change how it acts.
It was picked up through random genetic sampling of swabs submitted by people testing positive for the virus, and was first found in Nelson Mandela Bay, around Port Elizabeth.
What mutations did scientists find?
There are two key mutations on the South African variant that appear to give it an advantage over older versions of the virus – these are called N501Y and E484K.
Both are on the spike protein of the virus, which is a part of its outer shell that it uses to stick to cells inside the body, and which the immune system uses as a target.
They appear to make the virus spread faster and may give it the ability to slip past immune cells that have been made in response to a previous infection or a vaccine.
What does N501Y do?
N501Y changes the spike in a way which makes it better at binding to cells inside the body.
This means the viruses have a higher success rate when trying to enter cells when they get inside the body, meaning that it is more infectious and faster to spread.
This corresponds to a rise in the R rate of the virus, meaning each infected person passes it on to more others.
N501Y is also found in the Kent variant found in England, and the two Brazilian variants of concern – P.1. and P.2.
What does E484K do?
The E484K mutation found on the South African variant is more concerning because it tampers with the way immune cells latch onto the virus and destroy it.
Antibodies – substances made by the immune system – appear to be less able to recognise and attack viruses with the E484K mutation if they were made in response to a version of the virus that didn’t have the mutation.
Antibodies are extremely specific and can be outwitted by a virus that changes radically, even if it is essentially the same virus.
South African academics found that 48 per cent of blood samples from people who had been infected in the past did not show an immune response to the new variant. One researcher said it was ‘clear that we have a problem’.
Vaccine makers, however, have tried to reassure the public that their vaccines will still work well and will only be made slightly less effective by the variant.
How many people in the UK have been infected with the variant?
At least 217 Brits have been infected with this variant, according to Public Health England’s random sampling.
The number is likely to be far higher, however, because PHE has only picked up these cases by randomly scanning the genetics of around 15% of all positive Covid tests in the UK.
Where else has it been found?
According to the PANGO Lineages website, the variant has been officially recorded in 31 other countries worldwide.
The UK has had the second highest number of cases after South Africa itself.
Will vaccines still work against the variant?
So far, Pfizer and Moderna’s jabs appear only slightly less effective against the South African variant.
Studies into how well Oxford University/AstraZeneca‘s jab will work against the South African strain are still ongoing. A small study of young people found it offered them minimal protection against mild coronavirus, although this is not the point of the vaccine, which is intended to prevent severe illness and death.
Johnson & Johnson actually trialled its jab in South Africa while the variant was circulating and confirmed that it blocked 57 per cent of coronavirus infections in South Africa, which meets the World Health Organization’s 50 per cent efficacy threshold.