“When will it end?”: How a changing virus reshapes scientists’ views on COVID-19

CHICAGO (Reuters) – Chris Murray, a Washington University disease expert whose projections of COVID-19 infections and deaths are being closely monitored around the world, are changing his assumptions about the evolution of the pandemic.

Murray had until recently been hopeful that the discovery of more effective vaccines could help countries achieve immunity to the herd or nearly eliminate transmission through a combination of inoculation and previous infection. But in the past month, data from a vaccine study in South Africa have shown that not only could a rapidly spreading variant of coronavirus diminish the effect of the vaccine, but it could also steal the natural immunity of people who were previously infected.

“I couldn’t sleep” after seeing the data, Murray, director of the Seattle Institute for Health Metrics and Assessment, told Reuters. “When will it end?” he wondered, referring to the pandemic. It is currently updating its model to explain the ability of variants to get rid of natural immunity and expects to offer new projections as early as this week.

A new consensus is emerging among scientists, according to Reuters interviews with 18 specialists who are closely monitoring the pandemic or working to reduce its impact. Many have described how the discovery late last year of two vaccines with about 95% effectiveness against COVID-19 initially raised hopes that the virus could be largely contained, similar to how measles was.

But, they say, data in recent weeks on new variants in South Africa and Brazil have undermined this 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 disease and death for years to come.

As a result, the scientists said, people might expect to continue to take action, such as wearing a routine mask and avoiding crowded places during COVID-19 surges, especially for people at high risk.

Even after the vaccination, “I would still like to wear a mask if there was a variant there,” said Dr. Anthony Fauci, chief medical adviser to US President Joe Biden. “All you need is a little push of a variant (which causes) another increase, and that’s where the prediction goes” about when life returns to normal.

Some scientists, including Murray, acknowledge that the outlook could improve. The new vaccines, which have been developed at record speed, still seem to prevent hospitalizations and death even when the new variants are the cause of the infection. Many vaccine developers are working on booster vaccines and new vaccinations that could maintain a high level of efficacy against variants. And scientists say there is still much to learn about the immune system’s ability to fight the virus.

Already, COVID-19 infection rates have fallen in many countries since early 2021, with some dramatic reductions in severe disease and hospitalization among the first groups of people to be vaccinated.

WORSE THAN FLU

Murray said that if the South African variant or similar mutants continued to spread rapidly, the number of cases of COVID-19 resulting in hospitalization or death the following winter could be four times higher than the flu. The approximate estimate is an effective 65% vaccine given to half the population of a country. At worst, this could account for up to 200,000 US-related COVID-19 deaths over the winter, based on federal government estimates of annual influenza deaths.

His institute’s current forecast, which runs until June 1, estimates that there will be another 62,000 deaths in the United States and 690,000 deaths worldwide due to COVID-19 by then. The model includes assumptions about vaccination rates, as well as the transmissibility of South African and Brazilian variants.

The change in thinking among scientists has influenced the government’s more cautious statements about when the pandemic will end. Britain said last week that it expects a slow onset of one of the world’s tightest blockages, despite having one of the fastest vaccination mechanisms.

The US government’s predictions of a return to a more normal lifestyle have been repeatedly rejected, most recently from late summer until Christmas and then until March 2022. Israel issues “Green Pass” immunity documents to people who have returned from COVID-19 or were vaccinated, allowing them to return to hotels or theaters. The documents are only valid for six months, as it is not clear how long the immunity will last.

“What does it mean to get through the emergency phase of this pandemic?” Said Stefan Baral, an epidemiologist at the Johns Hopkins School of Public Health. While some experts have questioned whether countries could completely eradicate any case of COVID-19 through vaccines and strict blockages, Baral sees the targets as more modest but still significant. “In my mind, hospitals are not full, ICUs are not full, and people do not pass tragically,” he said.

“SCIENTIFIC WHIPLASH”

From the beginning, the new coronavirus has been a moving target.

At the beginning of the pandemic, top scientists warned that the virus could become endemic and “may never go away,” including Dr. Michael Ryan, head of the World Health Organization’s emergency program.

However, they had much to learn, including whether it would be possible to develop a vaccine against the virus and how quickly it would move. Would it be more like measles, which can be kept almost entirely at a distance in communities with high rates of inoculation or influenza, which infects millions each year globally?

For most of 2020, many scientists have been surprised and assured that the coronavirus has not changed significantly enough to become more transmissible or deadly.

A major discovery took place in November. Pfizer Inc. and its German partner BioNTech SE, as well as Moderna Inc., said their vaccines were approximately 95% effective in preventing COVID-19 in clinical trials, a much higher rate of effectiveness than any flu vaccine.

At least some of the scientists interviewed by Reuters said that, even after these results, they did not expect the vaccines to eliminate the virus. But many told Reuters that the data raised hopes in the scientific community that a virtual elimination of COVID-19 would be possible if only the world could be vaccinated fast enough.

“We all felt pretty optimistic before Christmas with the first vaccines,” said Azra Ghani, president of infectious disease epidemiology at Imperial College London. We do not necessarily expect such high-efficiency vaccines to be possible in that first generation.

Optimism proved short-lived. In late December, Britain warned of a new, more transmissible variant that was fast becoming the dominant form of coronavirus in the country. At the same time, the researchers learned about the impact of faster-spreading variants in South Africa and Brazil.

Phil Dormitzer, a top vaccine scientist at Pfizer, told Reuters in November that the success of the US drug vaccine indicated that the virus was “vulnerable to immunization” in what he called “a breakthrough for humanity.” ”. In early January, he acknowledged that the variants announced a “new chapter” in which companies will have to constantly monitor changes that could reduce the effect of vaccines.

At the end of January, the impact on vaccines became even clearer. Novavax clinical trial data showed that its vaccine was 89% effective in a UK study, but only 50% effective in preventing COVID-19 in South Africa. This was followed a week later by data showing that the AstraZeneca PLC vaccine offered limited protection against mild disease against the South African variant.

The latest change of heart has been considerable, several scientists told Reuters. Shane Crotty, a virologist at the La Jolla Institute of Immunology in San Diego, described it as a “scientific whip”: in December, he thought it was plausible to achieve the so-called “functional eradication” of measles-like coronavirus.

Now, “vaccinating as many people as possible is still the same answer and the same way before December 1 or January 1,” Crotty said, “but the expected result is not the same.”