COVID Measures Will Not End When Vaccine Arrives, Experts Say
2020-10-29
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1The arrival of the first COVID-19 vaccine will not mean people can throw away their face masks, experts say.
2Face coverings, social distancing and a lot of handwashing still will be required for some time after COVID-19 vaccines become available.
3But for how long? That depends on how effective the vaccines are and how long protection lasts.
4Such questions will not be answered when the first injections arrive.
5"This vaccine is not likely to be a suit of armor," said William Schaffner, an expert on infectious disease at Vanderbilt University Medical Center in Tennessee.
6In other words, a vaccine is not likely to be 100 percent effective.
7 Seasonal influenza vaccines, for example, have been 60 percent effective, at best, in recent years.
8The least efficient vaccines were only 10 percent effective.
9The United States Food and Drug Administration, FDA, has said it aims to have a 50 percent rate of effectiveness in COVID-19 vaccines.
10A partly effective vaccine might help high-risk groups, such as healthcare workers or those with existing health problems.
11But it might not be right for the general population, noted Jesse Goodman, an infectious disease expert and former Chief Scientist at the FDA.
12"...That's not the vaccine you would ideally immunize 300 million people with," he said.
13"Even if everybody was immunized, that's probably not enough immunity in the population to stop the virus from spreading."
14Goodman is now working as a professor at Georgetown University in Washington, D.C.
15Even an imperfect vaccine could help if it means people get less severe health problems and stay out of the hospital, experts note.
16People who get flu shots usually get less severe cases of the disease than those who do not get an injection, even when the vaccine is not very effective.
17Yet, "there is the risk that even the vaccinated people may unconsciously spread infection," Goodman said.
18Some experts call this a "worst-case scenario": a vaccine that works well enough to prevent patients from getting sick, but not well enough to stop them from spreading the virus.
19The vaccine could produce an immune response that does not completely block the virus but reduces it enough so that the patient does not experience symptoms of the disease.
20However, patients without the usual symptoms can still be infectious.
21That is a big part of what makes COVID-19, the disease caused by the coronavirus, so hard to control.
22The vaccine also may not protect everyone equally.
23There may be "big, big differences" in how children, adults and the very old respond to a vaccine, said Paul Duprex.
24He is director of the University of Pittsburgh Center for Vaccine Research.
25Flu vaccines usually do not work as well in older people, for example.
26People with some existing health conditions may respond better or worse than others.
27Also, there may be differences among different ethnic groups.
28"Biology is not black and white," Duprex said.
29"Biology is a super gray thing."
30When we can take face masks off also will depend on how many people get their vaccine injections.
31The goal is to get enough people immunized so that the virus has a hard time finding new people to infect.
32That is a point known as herd immunity.
33However, opinion studies show that the number of people willing to get a vaccine as soon it becomes available is dropping.
34In one study, nearly half of respondents said they would not get the vaccine.
35"We may be at a point where we actually don't have the ability to get to that herd immunity," said Daniel Larremore, a University of Colorado computer science professor who models disease transmission.
36 If that happens, he added, "we're going to continue to need other measures," such as masking and social distancing.
37Once vaccines become widely available, it still might be wise to keep your mask.
38Scientists will not immediately know how long the new vaccines offer protection.
39"If the trial's been going on for six months, we're going to not really know if the immunity lasts three, five or 10 years," Larremore said.
40Scientists also do not know how long the body's defenses remain active after a natural infection with the virus.
41Viruses related to COVID-19 cause common colds.
42Such viruses create immune responses that lessen after a few months to a couple years.
43Medical experts say people should expect to keep their masks on at least through most of 2021, while the vaccines become available and scientists learn more about them.
44Even then, the virus may not disappear completely.
45 COVID-19 may become a common threat to public health.
46"I think if you were a betting person, you would say this probably won't completely go away," Georgetown's Goodman said.
47"But, in nature, strange things happen."
48I'm Ashley Thompson. And I'm Caty Weaver.
1The arrival of the first COVID-19 vaccine will not mean people can throw away their face masks, experts say. 2Face coverings, social distancing and a lot of handwashing still will be required for some time after COVID-19 vaccines become available. But for how long? That depends on how effective the vaccines are and how long protection lasts. Such questions will not be answered when the first injections arrive. 3"This vaccine is not likely to be a suit of armor," said William Schaffner, an expert on infectious disease at Vanderbilt University Medical Center in Tennessee. 4In other words, a vaccine is not likely to be 100 percent effective. Seasonal influenza vaccines, for example, have been 60 percent effective, at best, in recent years. The least efficient vaccines were only 10 percent effective. 5The United States Food and Drug Administration, FDA, has said it aims to have a 50 percent rate of effectiveness in COVID-19 vaccines. 6A partly effective vaccine might help high-risk groups, such as healthcare workers or those with existing health problems. But it might not be right for the general population, noted Jesse Goodman, an infectious disease expert and former Chief Scientist at the FDA. 7"...That's not the vaccine you would ideally immunize 300 million people with," he said. "Even if everybody was immunized, that's probably not enough immunity in the population to stop the virus from spreading." 8Goodman is now working as a professor at Georgetown University in Washington, D.C. 9Vaccinated but infectious 10Even an imperfect vaccine could help if it means people get less severe health problems and stay out of the hospital, experts note. People who get flu shots usually get less severe cases of the disease than those who do not get an injection, even when the vaccine is not very effective. 11Yet, "there is the risk that even the vaccinated people may unconsciously spread infection," Goodman said. 12Some experts call this a "worst-case scenario": a vaccine that works well enough to prevent patients from getting sick, but not well enough to stop them from spreading the virus. 13The vaccine could produce an immune response that does not completely block the virus but reduces it enough so that the patient does not experience symptoms of the disease. 14However, patients without the usual symptoms can still be infectious. That is a big part of what makes COVID-19, the disease caused by the coronavirus, so hard to control. 15The vaccine also may not protect everyone equally. There may be "big, big differences" in how children, adults and the very old respond to a vaccine, said Paul Duprex. He is director of the University of Pittsburgh Center for Vaccine Research. 16Flu vaccines usually do not work as well in older people, for example. People with some existing health conditions may respond better or worse than others. Also, there may be differences among different ethnic groups. 17"Biology is not black and white," Duprex said. "Biology is a super gray thing." 18Vaccine indecision 19When we can take face masks off also will depend on how many people get their vaccine injections. 20The goal is to get enough people immunized so that the virus has a hard time finding new people to infect. That is a point known as herd immunity. 21However, opinion studies show that the number of people willing to get a vaccine as soon it becomes available is dropping. In one study, nearly half of respondents said they would not get the vaccine. 22"We may be at a point where we actually don't have the ability to get to that herd immunity," said Daniel Larremore, a University of Colorado computer science professor who models disease transmission. If that happens, he added, "we're going to continue to need other measures," such as masking and social distancing. 23Once vaccines become widely available, it still might be wise to keep your mask. Scientists will not immediately know how long the new vaccines offer protection. 24"If the trial's been going on for six months, we're going to not really know if the immunity lasts three, five or 10 years," Larremore said. 25Scientists also do not know how long the body's defenses remain active after a natural infection with the virus. 26Viruses related to COVID-19 cause common colds. Such viruses create immune responses that lessen after a few months to a couple years. 27Medical experts say people should expect to keep their masks on at least through most of 2021, while the vaccines become available and scientists learn more about them. 28Even then, the virus may not disappear completely. COVID-19 may become a common threat to public health. 29"I think if you were a betting person, you would say this probably won't completely go away," Georgetown's Goodman said. "But, in nature, strange things happen." 30I'm Ashley Thompson. And I'm Caty Weaver. 31Steve Baragona reported this story for VOA News. Ashley Thompson adapted it for VOA Learning English. George Grow was the editor. 32_________________________________________________________ 33Words in This Story 34armor - n. a hard covering that protects something (such as a vehicle or an animal) 35immunize - v. to give (someone) a vaccine to prevent infection by a disease 36unconsciously - adv. not aware of something 37scenario - n. a description of what could possibly happen 38response - n. something that is done as a reaction to something else 39symptom - n. a change in the body or mind which indicates that a disease is present 40herd - n. a large group of people 41transmission - n. the act or process by which something is spread or passed from one person or thing to another