Scientists Warn of Going Too Fast to Develop Coronavirus Vaccine
2020-03-16
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1Drug manufacturers are trying to develop a vaccine for the new coronavirus as quickly as possible in an effort to slow its spread.
2But scientists and medical experts are concerned that moving too quickly to release a vaccine for the virus could create added risk.
3Studies suggest that coronavirus vaccines carry the risk of what is known as vaccine enhancement.
4This is a condition in which the vaccine can make the disease worse when a vaccinated person is infected with the virus.
5Scientists do not know what causes vaccine enhancement,
6but it has prevented the successful development of a coronavirus vaccine.
7There are many coronaviruses, such as the one responsiblefor Severe Acute Respiratory Syndrome, in 2003,also known as SARS.
8Other coronaviruses have been linked to Middle East Respiratory Syndrome, known as MERS, and even the common cold.
9COVID-19 is the name of the disease resulting from infection with the new coronavirus.
10Normally, researchers need months of tests to study the possibility of vaccine enhancement in animals.
11But the Reuters news agency reports that some drug-makers are moving forward with limited human testing because of the new coronavirus outbreak.
12Peter Hotez is head of the National School of Tropical Medicine at Baylor College of Medicine in Texas.
13Hotez told Reuters that he understands the need to speed up development of a vaccine.
14But he added, "...from everything I know, this is not the vaccine to do it with."
15Hotez worked on the development of a vaccine for the SARS virus in the early 2000s.
16He said researchers at the time found that some vaccinated animals developed more severe disease compared to unvaccinated animals when they became infected.
17"The way you reduce that risk is first you show it does not occur in laboratory animals," he added.
18Hotez spoke this month to a United States congressional committee about the need to provide public money for vaccine research.
19There are no vaccines for any of the coronaviruses that have caused outbreaks in the past 20 years, Reuters noted.
20But health experts believe at this time that speeding vaccine development is worth taking the risk.
21The World Health Organization (WHO) called a meeting last month to organize efforts to fight the new coronavirus.
22The meeting was not open to the public.
23At the conference, scientists representing government-supported research groups and drug-makers agreed that the threat was severe.
24Four people attending the meeting told Reuters that vaccine developers agreed that efforts should move forward quickly to human tests before animal testing was completed.
25Marie-Paule Kieny is a doctor and a former official with the WHO.
26She said that moving forward quickly can create new risks.
27"You have to balance this with the risk that you impose on a small number of people, and do all you can do to mitigate this risk as much as possible," she told Reuters.
28Researchers and drug companies are developing at least 20 possible vaccines to help protect against the new coronavirus.
29The biotechnology company Moderna is working with the U.S. government-supported National Institutes of Health (NIH) on one vaccine candidate.
30It is said to be closest to human testing.
31Moderna announced a trial with 45 people in Seattle, Washington this month.
32Since that area was chosen, it has had many cases of the new coronavirus, including more than 20 deaths.
33The NIH told Reuters that testing on animals for vaccine enhancement will take place at the same time as human tests.
34The NIH said the trial is expected to last 14 months.
35Another company, Inovio Pharmaceuticals, is developing a coronavirus vaccine in cooperation with a Chinese company.
36It is not waiting for tests on animals and expects to start testing on 30 U.S. volunteers in April.
37Inovio chief Joseph Kim said, "The community as a whole weighed that and said we don't want to delay the clinical process."
38Earlier work on coronaviruses and other vaccines have drug developers on guard for warning signs.
39The best-known example of vaccine enhancement took place in the United States in the 1960s.
40At the time, NIH researchers created a vaccine to fight a virus - called RSV - that caused lung infections in babies.
41But most of the babies who received the vaccine developed severe cases of the disease, and two youngsters died.
42Research has shown that coronaviruses have the ability to produce this kind of reaction.
43But testing for the risk of vaccine enhancement takes time because scientists must develop genetically-engineered mice to test the vaccine.
44Development of such animals is just starting in several laboratories around the world.
45Moderna, Inovio and several other companies are not waiting for that process to be completed.
46They want to carry out tests on humans in record time.
47The latest new coronavirus, which causes COVID-19, was first identified in late December.
48Johnson & Johnson also is trying to create a vaccine.
49The company is developing animal models to test for vaccine enhancement.
50It hopes to begin human tests by October.
51Johan Van Hoof, head of the company's vaccine division, said, "People know how traumatic the RSV experience was."
52He added "When you see signals in animals like this, we should not ignore them."
53I'm Mario Ritter Jr.
54And I'm Ashley Thompson.
1Drug manufacturers are trying to develop a vaccine for the new coronavirus as quickly as possible in an effort to slow its spread. 2But scientists and medical experts are concerned that moving too quickly to release a vaccine for the virus could create added risk. 3Studies suggest that coronavirus vaccines carry the risk of what is known as vaccine enhancement. This is a condition in which the vaccine can make the disease worse when a vaccinated person is infected with the virus. 4Scientists do not know what causes vaccine enhancement, but it has prevented the successful development of a coronavirus vaccine. 5There are many coronaviruses, such as the one responsiblefor Severe Acute Respiratory Syndrome, in 2003,also known as SARS. Other coronaviruses have been linked to Middle East Respiratory Syndrome, known as MERS, and even the common cold. 6COVID-19 is the name of the disease resulting from infection with the new coronavirus. 7Normally, researchers need months of tests to study the possibility of vaccine enhancement in animals. But the Reuters news agency reports that some drug-makers are moving forward with limited human testing because of the new coronavirus outbreak. 8Peter Hotez is head of the National School of Tropical Medicine at Baylor College of Medicine in Texas. 9Hotez told Reuters that he understands the need to speed up development of a vaccine. But he added, "...from everything I know, this is not the vaccine to do it with." 10Hotez worked on the development of a vaccine for the SARS virus in the early 2000s. He said researchers at the time found that some vaccinated animals developed more severe disease compared to unvaccinated animals when they became infected. 11"The way you reduce that risk is first you show it does not occur in laboratory animals," he added. 12Hotez spoke this month to a United States congressional committee about the need to provide public money for vaccine research. There are no vaccines for any of the coronaviruses that have caused outbreaks in the past 20 years, Reuters noted. 13But health experts believe at this time that speeding vaccine development is worth taking the risk. 14The World Health Organization (WHO) called a meeting last month to organize efforts to fight the new coronavirus. The meeting was not open to the public. 15At the conference, scientists representing government-supported research groups and drug-makers agreed that the threat was severe. Four people attending the meeting told Reuters that vaccine developers agreed that efforts should move forward quickly to human tests before animal testing was completed. 16Marie-Paule Kieny is a doctor and a former official with the WHO. She said that moving forward quickly can create new risks. "You have to balance this with the risk that you impose on a small number of people, and do all you can do to mitigate this risk as much as possible," she told Reuters. 17Testing moving forward 18Researchers and drug companies are developing at least 20 possible vaccines to help protect against the new coronavirus. 19The biotechnology company Moderna is working with the U.S. government-supported National Institutes of Health (NIH) on one vaccine candidate. It is said to be closest to human testing. 20Moderna announced a trial with 45 people in Seattle, Washington this month. Since that area was chosen, it has had many cases of the new coronavirus, including more than 20 deaths. 21The NIH told Reuters that testing on animals for vaccine enhancement will take place at the same time as human tests. The NIH said the trial is expected to last 14 months. 22Another company, Inovio Pharmaceuticals, is developing a coronavirus vaccine in cooperation with a Chinese company. It is not waiting for tests on animals and expects to start testing on 30 U.S. volunteers in April. 23Inovio chief Joseph Kim said, "The community as a whole weighed that and said we don't want to delay the clinical process." 24Early warning signs 25Earlier work on coronaviruses and other vaccines have drug developers on guard for warning signs. 26The best-known example of vaccine enhancement took place in the United States in the 1960s. At the time, NIH researchers created a vaccine to fight a virus - called RSV - that caused lung infections in babies. But most of the babies who received the vaccine developed severe cases of the disease, and two youngsters died. 27Research has shown that coronaviruses have the ability to produce this kind of reaction. But testing for the risk of vaccine enhancement takes time because scientists must develop genetically-engineered mice to test the vaccine. Development of such animals is just starting in several laboratories around the world. 28Moderna, Inovio and several other companies are not waiting for that process to be completed. They want to carry out tests on humans in record time. The latest new coronavirus, which causes COVID-19, was first identified in late December. 29Johnson & Johnson also is trying to create a vaccine. The company is developing animal models to test for vaccine enhancement. It hopes to begin human tests by October. 30Johan Van Hoof, head of the company's vaccine division, said, "People know how traumatic the RSV experience was." He added "When you see signals in animals like this, we should not ignore them." 31I'm Mario Ritter Jr. 32And I'm Ashley Thompson. 33Julie Steenhuysen reported this story for Reuters. Mario Ritter Jr. adapted it for VOA Learning English. George Grow was the editor. 34________________________________________________________________ 35Words in This Story 36vaccine enhancement -n. when a vaccine causes an increase in a viral infection 37impose -v. to cause something to affect a person using a form of authority 38mitigate -v. to make something less harmful or severe 39clinical -adj. related to treating real patients 40traumatic -n. related to or causing serious problems or harm