As the pandemic rages on and there is no sign that it is peaking locally, here is an interesting article on what the future holds from the Wall Street Journal.
The Covid Race to Watch: Vaccines vs. Variants
Omicron won’t be the omega of Covid-19 variants. But global vaccination is the key to making sure the disease becomes endemic—and a lot more manageable.
The Covid pandemic is ‘like a real-world evolution experiment,’ says one researcher. Can the variants beat the vaccines?
By
Daniela Hernandez
,
Sarah Toy
and
Jason Douglas
Updated Jan. 15, 2022 11:00 am ET
As the Covid-19 pandemic enters its third year, the world is settling in for the moment the disease becomes endemic—and less disruptive—at least in the U.S. Against that is the race to vaccinate while anticipating new variants.
The coronavirus that causes Covid-19 has continued to turn up winning numbers in the evolutionary lottery, alighting on mutations that can help it survive and thrive. With uneven Covid-19 vaccine uptake in the developed world and slow rollout in poorer nations, virologists say the virus has ample avenues to generate more variants that could challenge immune defenses developed through vaccination, infection or both.
“This will be like a real-world evolution experiment: Can the variants beat the vaccines?” says Alex Sigal, who leads researchers probing coronavirus variants at the Africa Health Research Institute in South Africa.
Vaccines, public-health experts say, are critical in ushering the world out of the pandemic and into the era of endemicity, along with routine testing and access to new antiviral medications. Endemic Covid-19 will be a more manageable disease in parts of the world with access to vaccines and robust medical care. Like the flu—another endemic disease—Covid-19’s power to spark major social disruptions such as business shutdowns and travel restrictions will likely diminish with time.
But unequal vaccination around the world threatens that trajectory. “Viruses don’t stop at national borders,” says Lisa Lee, an infectious-disease epidemiologist and associate vice president at Virginia Tech. “One of the things we’ve learned is that the health of a person in a place far away can affect us.”
A rise in mutations
The SARS-CoV-2 coronavirus, which causes Covid, is constantly mutating as it infects people and multiplies. Most of the time, the changes it undergoes as it replicates are neutral or even harmful to its survival. But every so often, one or a combination of those genetic tweaks give it an edge. As the world has witnessed with Omicron, which has roughly 50 mutations, that can result in setbacks: spikes in cases that stress healthcare systems and prompt authorities to renew travel restrictions and closures. These social disruptions can delay reaching endemicity, public-health experts say.
“As this virus is moving through populations and infecting larger numbers of people, it’s adapting to us as humans,” says Richard Lessells, an infectious-disease specialist at the KwaZulu-Natal Research Innovation and Sequencing Platform in Durban, South Africa, who worked with the scientists who identified Omicron. “It’s finding better ways to survive.”
Mutations can produce variants that more easily break into cells or that replicate more efficiently. They might make the pathogen look a bit different to immune systems, enabling it to outrun human defenses. Omicron has evolved to exploit these three viral characteristics, research suggests. More than half of its mutations are in its spike protein, a key structure that helps the virus infiltrate cells.
With immunity levels increasing world-wide through prior infection and vaccination, some researchers say the virus may be under unprecedented pressure to change as it moves through a partially vaccinated global population—which could give rise to new future variants of concern, the label the World Health Organization has applied so far to the Alpha, Beta, Gamma, Delta and Omicron versions of the virus.
“Delta is a response to Beta, and now Omicron is a response to everything that has come before,” says Theodora Hatziioannou, a Rockefeller University virologist studying how antibodies, the immune-system proteins that keep viruses from infecting cells, interact with variants, including Omicron.
Based on her lab’s work, the main driver of viral evolution is antibody evasion, she says. More and more research suggests that Omicron can evade vaccine- or infection-generated antibodies. On the bright side: Studies have also shown that boosters, or additional vaccine doses, increase protection against the variant.
Cause for hope?
Many researchers have long said that vaccines won’t be the silver bullet that eradicates the Covid-causing coronavirus, because vaccines, including highly effective ones like the one for measles and those for Covid, don’t fully prevent infection, meaning vaccinated people can still get the disease they were vaccinated against. Inoculations provide solid protection against hospitalization and death because the shots prime the immune system to fight off invaders, resulting in less severe disease. Experts say they don’t expect future variants to render vaccines useless, especially if vaccines and boosters continue to prevent the worst outcomes.
“It’s something that we can handle,” says Jason McLellan, a structural biologist at the University of Texas at Austin who has studied how coronavirus proteins interact with antibodies. “We always assumed that we have to reformulate the vaccine every so often.”
One important advantage that scientists have now in combating the virus: improved technology. In the past, the painstaking analysis of viral genomes to identify mutations and the divergent viral family trees they engender took months, if not years. Now, researchers are working with genomic surveillance systemshoned by scientists who studied Ebola outbreaks in Africa. So, viral samples fromSARS-CoV-2-infected individuals are sequenced within days and uploaded to databases that teem with the genomic fingerprint of thousands of other samples.
Scientists use the data to monitor the spread of variants across the world, observe which mutations they carry, and investigate what role these changes are playing in driving transmission and causing illness. Pharmaceutical companies can also take that readily available genetic information and adapt their vaccines to concerning variants.
Researchers are also exploring the possibility of a pan-coronavirus vaccine, a shot that would protect against a range of coronaviruses, including variants that might elude the vaccines available today.
Unequal spread
But virologists and epidemiologists say that fitful distribution of Covid-19 vaccines around the globe could facilitate the arrival of new variants. Pockets of unvaccinated people could give the virus ample opportunities to spread and mutate, they say.
“Each transmission is an opportunity for a mutation, and each mutation is an opportunity for more dangerous variants,” says Patrick Sullivan, a professor of epidemiology at Emory University’s Rollins School of Public Health.
Essentially, the more people the virus sickens, the more elegant an infiltrator it has the opportunity to become. High rates of vaccination around the globe can help tamp down spread and therefore the opportunity the virus has to mutate.
Wealthy countries have received the bulk of Covid-19 shots. Shipments to poorer countries have been increasing slowly, but some experts are concerned that those shipments could diminish: High-income countries have expanded their booster campaigns in response to Omicron and might decide to hold on to doses that were meant for donation. Moreover, many poorer countries lack strong distribution networks to disseminate vaccine.
“These variants will continue to emerge while the virus is still spreading. And if there’s inequity in the way we protect populations and inequity in the vaccine distribution, then there’s more chance of variants emerging in areas with higher levels of virus circulating,” Dr. Lessells says.
Some scientists, including Salim Abdool Karim, a clinical infectious-disease specialist and director of the Centre for the AIDS Program of Research in South Africa, believe that the virus will eventually reach a stage where one main variant will be here to stay.
“The question is: How long will it take us to get to that point?” he said.
Ms. Hernandez, a Wall Street Journal reporter in New York, can be reached at daniela.hernandez@wsj.com. Email Ms. Toy, a Journal reporter in New York, at sarah.toy@wsj.com, and Mr. Douglas, a Journal reporter in London, at jason.douglas@wsj.com.
