Visitors come up to receive an injection of the COVID-19 vaccine at the National Health Service center in Birmingham, UK Due to a scarce vaccine, the United Kingdom has extended the interval between doses.
Jacob King / PA Wire / Bloomberg via Getty Images
By Meredith Wadman
Science”s The COVID-19 report is supported by the Pulitzer Center and the Heising-Simons Foundation.
Paul Bieniasz did not write words in a sarcastic New Year’s Day statement he tweeted. If he wanted to create a new vaccine-resistant version of the coronavirus pandemic, the Rockefeller University pathologist wrote, “Having developed a remarkable two-dose vaccine, [I’d ]… INCLUDES MILITARY PEOPLE – ONLY THE SECOND DOSE. … If we let immunity go away for a short time, say 4 to 12 weeks, we may just be hitting the sweet spot ”- and creating a virus that can kill the vaccine.
Bieniasz was addressing the UK decision on Dec. 30 to allow up to 12 weeks between doses of two authorized vaccines, instead of the 3 or 4 weeks tested in clinical trials of the vaccines. UK vaccine experts aimed to get at least some protection into the arms of as many people as possible in the face of a huge rise in cases and fears of a new, more contagious spread of the virus.
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In a similar move to extend scarce vaccine supplies, Russia announced on Monday that it would test the two-dose Sputnik V vaccine to see if just one dose – the “Sputnik Light” – would be effective. And yesterday, the Trump administration announced that it would no longer maintain 50% of the vaccine supply available in the United States to ensure timely second doses.
But Bieniasz and other virologists worry that extending the dosing time could lead to millions of people having only partial immunity while waiting for their second dose – a potential breeding ground. for immunosuppressive mutations. “If we end up with everyone just getting one dose with no doses available for a boost in a timely manner, that would be, in my opinion, a problem,” said Florian Krammer, a pathologist at Icahn School of Medicine at Mount Sinai.
However, experts do not agree on the risk of long-delayed delays, especially when measuring against the out-of-control transmission of the pandemic coronavirus, SARS-CoV-2 , in many places. “It’s carnage,” says Andrew Read, an evolutionary microbiologist at Pennsylvania State University. “Twice as many people with partial immunity must be better than full immunity in half.”
But the highest case accounts also generate a unique milieu – with billions of viral reactions occurring every second – for mutations to arise as the virus makes mistakes in copying the genetic alphabet. . One viral variant, first observed in South Africa, has developed two mutations that inhibit the efficacy of antibodies used for the treatment of COVID-19, raising the notion that they also inhibit vaccine-induced antibodies.
One of these mutations reduced the ability of 10-fold or more antibodies from some COVID-19 patients recovered to neutralize viruses expressing spike coronavirus protein, according to a recent introduction with Jesse Bloom and Allison Greaney from the Fred Hutchinson Cancer Research Center and their colleagues.
Urologists are concerned that extending the dosing interval from, say, 3 weeks to 3 months, could accelerate the pace of such mutants by creating a pool of subimmune people that have enough antibodies to infect the virus reduce and avoid developing symptoms – but not enough to eliminate it. out. These people could inject viruses with mutations that allow them to avoid vaccine-induced antibodies – for example, by altering the amino acid sequence at a site where antibodies were previous attachment, preventing the virus from invading cells and reproducing. Since most COVID-19 vaccines generate immunity to just one protein, the spike protein on the surface of the virus, the newer vaccines may make it easier for mutant viruses to escape than other vaccines. arouse wider immunity, Read notes.
Some data support the possibility that complementary immunity could seed new seeds. For example, a recently published case study in New England Journal of Medicine reported that, in a long-term, terminal case of SARS-CoV-2 in a vaccinated human, the virus continued to move at a rapid rate compared to a circulating virus in the population in general.
But evolutionary biologists who use computer modeling to diagnose cases of viral “escape” from vaccines say there is not yet enough data to quantify this still-hypothetical risk, and no modification is likely to reduce vaccine efficacy. Bloom notes “even [the] Worst mutations ”seen so far have just eroded the effectiveness of antibodies from acquired patient blood.
“Most people I know who do dynamic modeling in public health and evolution think [vaccine escape] high school… worry. That it is more important to just vaccinate in general right now. I’m in that camp, “said Sarah Cobey, an epidemiologist and evolutionary biologist at the University of Chicago.
Historically, very few viruses have affected vaccines, with the exception of seasonal flu, which develops so quickly on its own – without vaccine pressure – that it requires a new vaccine- designed annually. The poliovirus moves much faster than the new coronavirus, but polio vaccines are still very effective. And the measles virus moves about twice every million times it repeats itself, according to an introduction published in October 2020. But in 57 years it has not been possible for the measles virus run the highly effective vaccine, made from live, attenuated virus, in part because the vaccine arouses such a wide range of antibodies that one movement has little effect.
If over time the novel coronavirus goes around dramatically, researchers can update the vaccines, says Lucy Van Dorp, a computer geneticist at University College London. She notes that the mRNA vaccines produced by Pfizer and Moderna are “very suitable for updates.” The chief executive of BioNTech, which first developed the Pfizer vaccine, said Financial Times “We could make a new vaccine within 6 weeks. ”
However, scientists would like to solve their theoretical debate with data. Laboratory studies are examining how well antibodies from vaccinated individuals neutralize different types of the virus. And data expected soon from late vaccine trials in South Africa, which began before the emergence of the new worrying pressure in that country, should clarify the potential for that snoring to escape the those vaccines.
In the meantime, a live trial in extending the dose period has begun in the United Kingdom. Bieniasz says he can’t say for sure whether anti-vaccine viral rays will come. “But if that was my goal then I would do it this way. “