Scientists Test mRNA Vaccines to Protect Against Bird Flu
2024-06-11
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1From VOA Learning English, this is the Health & Lifestyle report.
2Scientists are testing next-generation vaccines to deal with the spread of bird flu in the United States.
3The vaccines use the same mRNA technology that led to the development of COVID-19 shots in record time.
4The U.S. Agriculture Department is planning to test a vaccine, developed by University of Pennsylvania researchers, by giving it to cows in order to protect farm workers.
5They say this could lessen the chance for the virus to jump into people and mutate, or change, in ways that could cause human-to-human spread.
6Meanwhile, officials at the U.S. Department of Health and Human Services have been talking to drugmakers about possible mRNA flu vaccines for people.
7These mRNA vaccines would be in addition to the millions of bird flu vaccines already in government hands.
8"If there's a pandemic, there's going to be a huge demand for vaccine," said Richard Webby, a flu researcher at St. Jude Children's Research Hospital in Memphis.
9The more vaccines, the better, he added.
10Since 2020, the bird flu virus has been spreading among different kinds of animals in many countries.
11In March, it was found in U.S. dairy cows.
12However, investigators think it may have been in cows since December.
13Recently, the USDA announced it had been found in alpacas for the first time.
14At least three dairy farm workers in the U.S. have been diagnosed with bird flu.
15Their illnesses were not severe. But earlier versions of the same H5N1 flu virus have been deadly to humans in other parts of the world.
16And U.S. officials are taking steps to be prepared if the virus mutates to a deadlier version or permits it to spread more easily from person to person.
17Health officials say they already have two candidate vaccines for people that appear to be well-matched to the bird flu virus in U.S. dairy cows.
18They say, hundreds of thousands of prepared vaccines could go out immediately.
19And nearly 10 million more treatments could be produced in a few months.
20The drugmaker CSL Seqirus said the U.S. government hired it to fill and finish about 4.8 million shots that could be completed by late summer.
21But the production lines for flu vaccines are already working on this autumn's seasonal shots.
22And drugmakers would have to stop the lines to produce the bird flu vaccine.
23So, the government has been looking for another, faster pathway: the mRNA technology used by drugmakers Moderna and Pfizer to produce the vaccines against COVID-19.
24Vaccine makers usually add elements of an inactive or weakened virus to the shot mixture.
25But with mRNA vaccines, scientists instead create a genetic material to direct the human body to produce antibodies and recognize and destroy the virus.
26Moderna already has a bird flu mRNA vaccine in very early testing in humans.
27In a statement, Moderna said they "are in discussions with the U.S. government on advancing our pandemic flu candidate."
28Similar work has been going on at Pfizer.
29Company researchers in December gave human volunteers an mRNA vaccine against a version of bird flu that is somewhat similar to the one in cows.
30Since then, researchers have performed a lab experiment exposing blood samples from those volunteers to the version seen in dairy cows.
31Pfizer said in a statement that they saw "notable increases in antibody responses."
32As for cows, University of Pennsylvania researcher Scott Hensley worked with Nobel-prize winner Drew Weissman on an experimental vaccine similar to the Moderna one for people.
33In first-step testing, mice and ferrets produced high levels of bird flu virus-fighting antibodies after vaccination.
34In another experiment, researchers infected one group of ferrets after vaccination.
35Then they compared what happened to unvaccinated ferrets.
36All the vaccinated animals survived and the unvaccinated did not, Hensley said.
37"The vaccine was really successful," said Webby of St. Jude Children's Research Hospital in Memphis.
38His lab did that work last year in partnership with Hensley.
39The cow study will be similar to the early testing done in smaller animals.
40The plan is for about 10 small cows to be vaccinated, half with one shot and half with another.
41Then their blood will be examined to look for how much bird flu-fighting antibodies were produced.
42Hensley said that if a vaccine reduces the amount of virus in the cow, "then ultimately we reduce the chance that a mutant virus that spreads in humans is going to emerge."
43That's the Health & Lifestyle report.
44I'm Anna Matteo.
45And I'm Andrew Smith.
1From VOA Learning English, this is the Health & Lifestyle report. 2Scientists are testing next-generation vaccines to deal with the spread of bird flu in the United States. The vaccines use the same mRNA technology that led to the development of COVID-19 shots in record time. 3The U.S. Agriculture Department is planning to test a vaccine, developed by University of Pennsylvania researchers, by giving it to cows in order to protect farm workers. They say this could lessen the chance for the virus to jump into people and mutate, or change, in ways that could cause human-to-human spread. 4Meanwhile, officials at the U.S. Department of Health and Human Services have been talking to drugmakers about possible mRNA flu vaccines for people. These mRNA vaccines would be in addition to the millions of bird flu vaccines already in government hands. 5"If there's a pandemic, there's going to be a huge demand for vaccine," said Richard Webby, a flu researcher at St. Jude Children's Research Hospital in Memphis. The more vaccines, the better, he added. 6Spread of bird flu virus 7Since 2020, the bird flu virus has been spreading among different kinds of animals in many countries. In March, it was found in U.S. dairy cows. However, investigators think it may have been in cows since December. Recently, the USDA announced it had been found in alpacas for the first time. 8At least three dairy farm workers in the U.S. have been diagnosed with bird flu. Their illnesses were not severe. But earlier versions of the same H5N1 flu virus have been deadly to humans in other parts of the world. And U.S. officials are taking steps to be prepared if the virus mutates to a deadlier version or permits it to spread more easily from person to person. 9Health officials say they already have two candidate vaccines for people that appear to be well-matched to the bird flu virus in U.S. dairy cows. They say, hundreds of thousands of prepared vaccines could go out immediately. And nearly 10 million more treatments could be produced in a few months. 10The drugmaker CSL Seqirus said the U.S. government hired it to fill and finish about 4.8 million shots that could be completed by late summer. But the production lines for flu vaccines are already working on this autumn's seasonal shots. And drugmakers would have to stop the lines to produce the bird flu vaccine. 11Looking for a faster pathway 12So, the government has been looking for another, faster pathway: the mRNA technology used by drugmakers Moderna and Pfizer to produce the vaccines against COVID-19. 13Vaccine makers usually add elements of an inactive or weakened virus to the shot mixture. But with mRNA vaccines, scientists instead create a genetic material to direct the human body to produce antibodies and recognize and destroy the virus. 14Moderna already has a bird flu mRNA vaccine in very early testing in humans. In a statement, Moderna said they "are in discussions with the U.S. government on advancing our pandemic flu candidate." 15Similar work has been going on at Pfizer. Company researchers in December gave human volunteers an mRNA vaccine against a version of bird flu that is somewhat similar to the one in cows. 16Since then, researchers have performed a lab experiment exposing blood samples from those volunteers to the version seen in dairy cows. Pfizer said in a statement that they saw "notable increases in antibody responses." 17As for cows, University of Pennsylvania researcher Scott Hensley worked with Nobel-prize winner Drew Weissman on an experimental vaccine similar to the Moderna one for people. 18In first-step testing, mice and ferrets produced high levels of bird flu virus-fighting antibodies after vaccination. 19In another experiment, researchers infected one group of ferrets after vaccination. Then they compared what happened to unvaccinated ferrets. All the vaccinated animals survived and the unvaccinated did not, Hensley said. 20"The vaccine was really successful," said Webby of St. Jude Children's Research Hospital in Memphis. His lab did that work last year in partnership with Hensley. 21The cow study will be similar to the early testing done in smaller animals. The plan is for about 10 small cows to be vaccinated, half with one shot and half with another. Then their blood will be examined to look for how much bird flu-fighting antibodies were produced. 22Hensley said that if a vaccine reduces the amount of virus in the cow, "then ultimately we reduce the chance that a mutant virus that spreads in humans is going to emerge." 23That's the Health & Lifestyle report. 24I'm Anna Matteo. 25And I'm Andrew Smith. 26Mike Stobbe and Lauran Neergaard reported this story for the Associated Press from. Anna Matteo adapted it for VOA Learning English. 27______________________________________________ 28Words in This Story 29mutate - v. to cause to undergo changes at the genetic level (mutation) 30dairy - n. milk from a cow or other domestic animal (such as a goat) 31diagnose - v. to recognize (something, such as a disease) by signs and symptoms 32advance - v. to bring or move forward 33sample - n. a part (as a set of individuals chosen from a whole population) used for investigating the whole 34response - n. a reaction of a living thing to a stimulus 35ultimately - adv. in the end 36emerge - v. to become known or apparent 37We want to hear from you. Our comment policy is here.