Can COVID-19 Still Be Eliminated? | Science | News | the sun

HIn fact, it is not yet known for certain whether or not COVID-19 will continue. It could still be, in principle at least, completely eliminated from human-to-human transmission, as it has already been done with other viruses. For example, smallpox was completely eradicated in 1980 after intense vaccination campaigns conducted since the 1960s – and since smallpox does not have an animal reservoir, it only spreads in humans, it does not have an animal reservoir. It simply no longer exists today. Likewise, the human transmission of the COVID-19 “cousin”, SARS-CoV-1, which causes severe acute respiratory syndrome (SARS), has been stopped completely. It made a leap to humans in 2002 and infected more than 8,000 people, killing nearly 800. After two years of isolating all the infected people, we were able to eliminate it – it’s still present in some animal tanks, but it’s no longer circulating in humans. .

So in theory, but really in theory, yes, COVID-19 can still be eliminated, either through vaccination or isolation. But in practice, let’s say that wasn’t the case (at all).

COVID-19 may be “close” to SARS, but they are two different viruses and do not behave completely. Granted, they both were / were as infectious as each other: One study It was published last summer in the medical journal The scalpel It is estimated that each person with COVID-19 passes the germ to about 2.5 other people on average, compared to 2.4 for SARS (by comparison, about 1.3 for the flu). However, and this is a major point, SARS tends to infect the deep airways and viruses that also settle in the depths of the lungs. It usually gives more severe symptoms Of those who, like COVID-19, come out of their noses or throat. So, the severity of the disease made SARS much easier to detect, and thus contain, than COVID-19, which often causes few or no symptoms.

Now, if this pathway does not seem possible (or in any case, not more difficult) for COVID-19, can we believe that vaccines may ultimately drive this virus out of humanity? Again, this is not impossible in principle. One could imagine a scenario in which immunity from vaccines, along with that acquired through virus infection, would ultimately have an effect similar to that of polio vaccines – except that COVID-19 came to us from an animal tank, and thus could make a jump to Human beings again.

Re-infection

However, acquired immunity can eventually weaken to the point where one can contract the virus again – and there have already been a large number of cases of re-infection with the COVID-19 virus that have been documented. In addition, the Corona virus itself changes over time. It does not mutate particularly quickly, note: about four times slower than the influenza virus, for example [https://www.livescience.com/coronavirus-mutation-rate.html]. But it appears that some mutations can allow them to escape from our antibodies, whether they result from vaccination or infection. So prof A study published in Nature Medicine At the beginning of the month Antibodies taken from people who had had COVID-19 and from people who had received the vaccine, were tested to see if they had neutralized the English (B117), South African (B.1.351) “variants” and the Brazilian (B.1.1.248). Result: Against the English variant, the antibodies work just as they do against the “usual” strains, but against the other two variants, it takes between 3.5 and 10 times the antibodies to do the same job. a Another study from Temperate nature Posted in March They reached very similar results. This is a very clear sign that the virus is developing a certain degree of resistance that could eventually allow it to continue spreading even after we have achieved the holy grail of herd immunity.

So it is perhaps not surprising that virologists and epidemiologists have surveyed From the site Temperate nature I recently discovered that 89% of them think it is “likely” (29%) or “very likely” (60%!) That COVID-19 will become a pandemic, meaning that it is permanently entrenched in humans. It is hardly more surprising than another text Last week appeared in Journal of the American Medical Association, Two clinical researchers were very pessimistic about the possibility of putting an end to this coronavirus forever: “It is not clear, they write, whether COVID-19 will become a seasonally endemic disease. There is still a lot of uncertainty about the potential for new variants to emerge and recur. “The loss of vaccine efficacy for each variant, and the critical issue of cross-immunization from one variable to another, and maintaining safe human behavior. However, the potential for COVID-19 is continuous and seasonal is real.”