CHICAGO (Reuters) – Chris Murray, a University of Washington disease expert whose projections of COVID-19 infections and deaths worldwide are closely monitored, is changing his assumptions about the pandemic’s course.
Until recently, Murray had hoped that the discovery of several effective vaccines could help countries achieve herd immunity, or almost eliminate transmission through a combination of inoculation and previous infection. But over the past month, data from a vaccine study in South Africa not only showed that a rapidly spreading coronavirus variant could dampen the vaccine’s effect, it could also bypass natural immunity in people 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 wondered, referring to the pandemic. He is currently updating his model to account for variants’ ability to escape natural immunity and expects to deliver new projections as early as this week.
According to Reuters interviews with 18 specialists who are closely monitoring the pandemic or working to curb its impact, a new consensus is emerging among scientists. Many described how the breakthrough of two vaccines with about 95% efficacy against COVID-19 late last year had initially raised hopes that the virus could be largely controlled, similar to the way measles has been.
But, they say, data from recent weeks on new varieties from South Africa and Brazil has undermined that optimism. They now believe that SARS-CoV-2 will not only stay with us as an endemic virus, which will continue to circulate in communities, but will likely cause a significant burden of illness and death in the years to come.
As a result, the scientists said, people could expect to continue taking measures such as wearing masks routinely and avoiding crowded places during COVID-19 peaks, especially for those at high risk.
Even after vaccination, “I would still want to wear a mask if there is a variant,” said Dr. Anthony Fauci, chief medical adviser to US President Joe Biden, in an interview. “All you need is a little movement of a variant (which ignites a new wave), and that’s what your prediction is about when life will return to normal.
Some scientists, including Murray, recognize that the outlook can improve. The new vaccines, which have been developed in record time, still appear to prevent hospitalization and death, even if new variants are the cause of infection. Many vaccine developers are working on booster shots and new vaccinations that could maintain a high level of efficacy against the variants. And scientists say there is still a lot to learn about the immune system’s ability to fight the virus.
Since the beginning of 2021, COVID-19 infections have already fallen in many countries, with a dramatic decrease in the number of serious illnesses and hospitalizations in the first groups of people to be vaccinated.
WORSE THAN THE FLU
Murray said that if the South African variant, or similar mutants, continue to spread rapidly, the rate of COVID-19 cases leading to hospitalization or death this winter could be four times higher than the flu. The rough estimate assumes a 65% effective vaccine that is given to half of a country’s population. In a worst-case scenario, that could add up to as many as 200,000 U.S. deaths from COVID-19 over the winter, based on federal government estimates of annual flu deaths.
His institute’s current forecast, which runs through June 1, assumes there will be 62,000 U.S. deaths and 690,000 global deaths from COVID-19 at that point. The model includes assumptions about vaccination coverage and 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 said last week it expects a slow turnout from one of the world’s toughest lockdowns, despite one of the fastest vaccinations.
US government predictions of a return to a more normal lifestyle have been repeatedly delayed, most recently from late summer to Christmas, and then to March 2022. Israel issues “Green Pass” immunity documents to people who have recovered from COVID- 19 or have been vaccinated, allowing them to return to hotels or theaters. The documents are only valid for six months because it is not clear how long the 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 can completely eradicate every case of COVID-19 through vaccines and stringent lockdowns, Baral sees the goals as more modest but still meaningful. “I think it’s that hospitals are not full, the ICs are not full and tragically people are passing by,” he said.
“SCIENTIFIC WHIPLASH”
From the beginning, the novel coronavirus has been a moving target.
Early in the pandemic, leading scientists warned that the virus could become endemic and “may never disappear,” including Dr. Michael Ryan, head of the World Health Organization’s emergency program.
Still, they still had a lot 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 almost completely kept at bay in communities with high vaccination rates, or the flu, which infects millions of people worldwide every 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 and Moderna Inc said their vaccines were about 95% effective in preventing COVID-19 in clinical trials, an efficacy rate much higher than any flu shot.
Even after those results, at least some of the scientists interviewed by Reuters said they did not expect the vaccines to eradicate the virus. But many told Reuters that the data is raising hope within the scientific community that it would be possible to virtually eradicate COVID-19 if the world could be vaccinated soon enough.
“We were all pretty optimistic about Christmas with those first vaccines,” said Azra Ghani, chair of infectious disease epidemiology at Imperial College London. “We didn’t necessarily expect such highly effective vaccines to be possible in that first generation.”
The optimism turned out to be 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. Around the same time, researchers learned about the impact of the faster-spreading variants in South Africa and Brazil.
Phil Dormitzer, a leading vaccine scientist at Pfizer, told Reuters in November that the success of the US drug company indicated the virus was “vulnerable to immunization” in what he called “a breakthrough for mankind.” At the beginning of January, he acknowledged that the variants heralded “a new chapter” in which companies will have to continuously monitor for mutations that could dampen the effect of vaccines.
At the end of January, the impact on vaccines became even more apparent. Novavax’s clinical trial data showed that the vaccine was 89% effective in a UK study, but only 50% effective in preventing COVID-19 in South Africa. That was followed a week later by data showing that the AstraZeneca PLC vaccine provided only limited protection against mild disease against the South African variant.
The most recent change of heart was significant, several 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 thought it plausible to achieve a so-called “functional eradication” of the coronavirus, similar to the measles.
Now, “getting as many people vaccinated as possible is still the same answer and the same way forward as December 1 or January 1,” said Crotty, “but the expected outcome is not the same.”
Reporting by Julie Steenhuysen in Chicago and Kate Kelland in London; additional reporting by Michael Erman in New York; Editing by Michele Gershberg and Cassell Bryan-Low