{"id":114280,"date":"2021-05-15T14:52:07","date_gmt":"2021-05-15T21:52:07","guid":{"rendered":"http:\/\/www.lankaweb.com\/news\/items\/?p=114280"},"modified":"2021-05-15T14:52:07","modified_gmt":"2021-05-15T21:52:07","slug":"five-reasons-why-you-dont-need-to-panic-about-coronavirus-variants","status":"publish","type":"post","link":"https:\/\/www.lankaweb.com\/news\/items\/2021\/05\/15\/five-reasons-why-you-dont-need-to-panic-about-coronavirus-variants\/","title":{"rendered":"Five reasons why you don\u2019t need to panic about coronavirus variants"},"content":{"rendered":"

by Cassandra Willyard Courtesy Technologyreview.com<\/strong><\/a><\/em><\/span><\/h2>\n\n\n

The hype around scariants\u201d is overblown. But we also shouldn\u2019t be too complacent.<\/strong><\/p>\n\n\n\n

On May\n10, the World Health Organization added a new virus to its list of covid-19\nvariants of global concern. The variant, B.1.617, is being blamed for the\nrunaway infections in India. It is the fourth addition to a list that also\nincludes variants first identified in the UK, South Africa, and\nBrazil. There is some available information to suggest increased\ntransmissibility,\u201d said Maria Van Kerkhove, WHO technical lead on covid-19, at\na briefing. <\/p>\n\n\n\n

With each new variant comes growing unease. News stories about double mutants\u201d<\/a> and\ndangerous variants\u201d stoke fears that these viruses will be able to evade the\nimmune response and render our best vaccines ineffective, sending us back into\nlockdown. But for the moment the virus hasn\u2019t fundamentally changed,\u201d says\nKartik Chandran, a virologist at Albert Einstein College of Medicine.<\/p>\n\n\n\n

Vaccines may become less effective over time, but there\u2019s no\nevidence that we\u2019re on the brink of catastrophe. I don\u2019t think that there\u2019s an\nimminent danger that we\u2019re going to go back to square one,\u201d says Thomas\nFriedrich, a virologist at the University of Wisconsin School of Veterinary\nMedicine. We should be concerned, but not freaked out.\u201d <\/p>\n\n\n\n

Here are five reasons why we can be cautiously optimistic.<\/p>\n\n\n\n

1. Vaccines work, even against troublesome variants<\/h4>\n\n\n\n

Early reports suggested that the current crop of covid-19\nvaccines might not work as well against some of the variants, including the one\nfirst identified in South Africa (B.1.351). In lab\ntests, antibodies from vaccinated individuals couldn\u2019t neutralize the virus as\neffectively as they could the original virus. But real-world data out of Qatar<\/a> suggests that the Pfizer vaccine works quite well,\neven against B.1.351. Full vaccination offered 75% protection against\nB.1.351 infections; that\u2019s less than the 95% efficacy reported in the trials\nfor the original virus but still a miracle,\u201d says Andrew Read, a disease\necologist at Pennsylvania State University. These vaccines are so good. We\u2019ve\ngot so much room to play with.\u201d <\/p>\n\n\n\n

Some\nvariants do seem to be better at dodging our immune system, at least in lab\nexperiments. For example, a small study posted on May 10<\/a> shows\nthat the newest variant of global concern \u2014 B.1.617\u2014 is more resistant to\nantibodies from people who have been vaccinated or have previously been\ninfected. Despite that, all 25 people who had received shots from Moderna or\nPfizer produced enough antibodies to neutralize the variant.<\/p>\n\n\n\n

2. The immune response is robust <\/h4>\n\n\n\n

Scientists\ntesting vaccine efficacy often focus on antibodies and their ability to block\nthe virus from infecting cells. In lab experiments, they mix blood from people\nwho have been infected or vaccinated with cells in a dish to see if antibodies\nin the blood can neutralize\u201d the virus. These experiments are easy to\nperform. But antibodies are a very narrow\nslice of what the immune response might be\u201d in the body, says Jennifer Dowd, an\nepidemiologist and demographer at the University of Oxford. <\/p>\n\n\n\n

Immune cells\ncalled T cells also help keep infections in check. These cells can\u2019t neutralize\nthe virus, but they can seek out infected cells and destroy them. That helps\nprotect against severe disease. And data from people who\u2019ve had covid-19\nsuggests that T-cell response should provide ample protection against most of\nthe SARS-CoV-2 variants.<\/p>\n\n\n\n

3. When vaccinated people do get infected, the shots protect\nagainst the worst outcomes<\/h4>\n\n\n\n

A vaccine that can block\ninfection is wonderful. But the most important thing is to keep people out of\nthe hospital and out of the ground,\u201d says Friedrich. And there\u2019s good evidence that the current vaccines do exactly\nthat. In South Africa, one dose of the Johnson & Johnson vaccine provided 85% protection<\/a> against\ncovid-19-related hospitalizations and deaths. At the time, 95% of cases were\ncaused by the B.1.351 variant. In Israel<\/a>, where\nB.1.1.7 has become the dominant strain, two doses of Pfizer offered 97%\nprotection against symptomatic covid-19 and hospitalizations linked to\ncovid-19.<\/p>\n\n\n\n

4. The same mutations keep popping up\u00a0<\/h4>\n\n\n\n

Once\nthe virus enters a cell, it begins to replicate. The more copies it makes, the greater the likelihood that random\nerrors, or mutations, will crop up. Most of these copying errors are inconsequential.\nA handful, however, might give the virus a leg up. For example, a\nspike-protein mutation known as D614G appears to help transmission of\nSARS-CoV-2. Another, E484K, might help the virus evade the body\u2019s antibody\nresponse. If the viruses carrying these advantageous mutations get transmitted\nfrom one person to the next, they can start to outcompete the viruses that lack\nthem, a process known as natural selection. That\u2019s how the B.1.1.7 variant,\nwhich is more transmissible, became the predominant strain in the US. <\/p>\n\n\n\n

In the case of SARS-CoV-2, the mutations that improve the\nvirus keep popping up in different parts of the globe, a phenomenon known as\nconvergent evolution. We are seeing the same combinations evolving over and over\nand over again,\u201d says Vaughn Cooper, an evolutionary biologist at the\nUniversity of Pittsburgh. Imagine a game of Tetris, Cooper writes in a recent story for Scientific\nAmerican<\/a>. A limited number of building blocks can be assembled\nin different ways, in different combinations, to achieve the same winning\nstructures.\u201d<\/p>\n\n\n\n

Cooper and\nsome other researchers see this evidence of convergent evolution as a hopeful\nsign: the virus may be running out of new ways to adapt to the current\nenvironment. It\u2019s actually a small deck of cards right now,\u201d he says. If we\ncan control infections, that deck of cards is going to remain small.\u201d<\/p>\n\n\n\n

5. If the effectiveness of the vaccines begins to wane, we\ncan make booster shots. <\/h3>\n\n\n\n

Eventually, the current vaccines will become less effective.\nThat\u2019s to be expected,\u201d Chandran says. But he expects that to happen\ngradually: There will be time for next-generation vaccines.\u201d Moderna has already begun testing the efficacy of a\nbooster shot aimed at protecting against B.1.351 (first identified in South\nAfrica). Last week the company released the initial results<\/a>.\nA third dose of the current covid-19 shot or a B.1.351-specific booster\nincreased protection against the variants first identified in South Africa and\nBrazil. But the new variant-specific booster prompted a bigger immune response\nagainst B.1.351 than the third dose of the original shot. <\/p>\n\n\n\n

That\u2019s\na relief for a couple of reasons. First, it demonstrates that variant-specific\nboosters can work. I think the feasibility of these RNA-based vaccines to\nproduce boosters is the achievement of our lifetime,\u201d Cooper says. <\/p>\n\n\n\n

But there\u2019s another, more obscure reason to celebrate these\nearly results. Some researchers have worried that a booster shot aimed at one\nof the variants might amplify the immune response against the original virus\ninstead. This phenomenon, known as original antigenic sin, sometimes occurs\nwhen the body is exposed to a virus that is similar, but not identical, to one\nit has already encountered. This can happen with repeated influenza exposures.\nIt can also occur in response to vaccination. So the fact that the Moderna\nbooster worked better than a third shot of the original formula provides some grounds\nfor optimism that antigenic sin won\u2019t be as much of a hurdle in fighting\nSARS-CoV-2. <\/p>\n\n\n\n

New trials on mixing different types of vaccines are\nunderway. Could vaccine\ncombinations help stop variants from bypassing our immune systems?<\/p>\n\n\n\n

But while we don\u2019t need to panic, now is also not the time\nfor complacency. Just because the current crop of variants seems to be\nrelatively tame doesn\u2019t mean every new variant will be. The odds are that\nwe\u2019re going to see a lot more of the same kinds of thing that we\u2019ve already\nseen,\u201d Chandran says. But very rare things can happen and do happen,\u201d he adds.\nAnd if those rare things confer a tremendous improvement in success, they may\nonly need to happen a couple of times.\u201d <\/p>\n\n\n\n

The surge in India is especially\nconcerning. That\u2019s giving the virus a lot of chances to pull the evolutionary\nslot-machine handle and maybe come up with a jackpot,\u201d Friedrich says. And\nwhile vaccine rollout has been going well in many rich countries, poorer\ncountries may not have widespread access to vaccines until 2022 or even later.\nWe have these amazing vaccines,\u201d Chandran says. We need to figure out a way\nto get them to everybody.\u201d<\/p>\n","protected":false},"excerpt":{"rendered":"

by Cassandra Willyard Courtesy Technologyreview.com The hype around scariants\u201d is overblown. But we also shouldn\u2019t be too complacent. On May 10, the World Health Organization added a new virus to its list of covid-19 variants of global concern. The variant, B.1.617, is being blamed for the runaway infections in India. It is the fourth addition […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"closed","sticky":true,"template":"","format":"standard","meta":{"footnotes":""},"categories":[122,132,174],"tags":[],"class_list":["post-114280","post","type-post","status-publish","format-standard","hentry","category-health","category-science","category--19-"],"_links":{"self":[{"href":"https:\/\/www.lankaweb.com\/news\/items\/wp-json\/wp\/v2\/posts\/114280","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.lankaweb.com\/news\/items\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.lankaweb.com\/news\/items\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.lankaweb.com\/news\/items\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.lankaweb.com\/news\/items\/wp-json\/wp\/v2\/comments?post=114280"}],"version-history":[{"count":0,"href":"https:\/\/www.lankaweb.com\/news\/items\/wp-json\/wp\/v2\/posts\/114280\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.lankaweb.com\/news\/items\/wp-json\/wp\/v2\/media?parent=114280"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.lankaweb.com\/news\/items\/wp-json\/wp\/v2\/categories?post=114280"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.lankaweb.com\/news\/items\/wp-json\/wp\/v2\/tags?post=114280"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}