Virus antibodies fade fast but not necessarily protection

Virus antibodies fade fast but not necessarily protection

Virus antibodies fade fast but not necessarily protection

New research suggests that antibodies the immune system makes to fight the new coronavirus may only last a few months in people with mild illness, but that doesn’t mean protection also is gone or that it won’t be possible to develop an effective vaccine.

“Infection with this coronavirus does not necessarily generate lifetime immunity,” but antibodies are only part of the story, said Dr. Buddy Creech, an infectious disease specialist at Vanderbilt University. He had no role in the work, published Tuesday in the New England Journal of Medicine.

The immune system remembers how to make fresh antibodies if needed and other parts of it also can mount an attack, he said.

Antibodies are proteins that white blood cells called B cells make to bind to the virus and help eliminate it. The earliest ones are fairly crude but as infection goes on, the immune system becomes trained to focus its attack and to make more precise antibodies.

Dr. Otto Yang and others at the University of California, Los Angeles, measured these more precise antibodies in 30 patients diagnosed with COVID-19 and four housemates presumed to have the disease. Their average age was 43 and most had mild symptoms.

Researchers found that the antibodies had a half-life of 36 days, which means that half of them would be gone after that much time. It dovetails with a previous report from China also suggesting antibodies quickly fade.

The results “call for caution regarding antibody-based ‘immunity passports,’ herd immunity, and perhaps vaccine durability,” the California authors write.

That’s true, Creech said, but other parts of the immune system also help confer protection. Besides churning out antibodies, B cells develop a memory so they know how to do that again if needed.

“They would get called into action very quickly when there’s a new exposure to the virus. It’s as if they lie dormant, just waiting,” he said.

Other white blood cells called T cells also are better able to attack the virus the next time they see it, Creech said.

Although circulating antibodies may not last long, what we need to know is if and how people remake antibodies if exposed to the coronavirus again and if they protect against another infection, Alison Criss, an immunologist at the University of Virginia, wrote in an email. “We also need to know if there is a protective T cell response” that reappears.

Vaccines, which provoke the immune system to make antibodies, might give longer-lasting protection than natural infection because they use purified versions of what stimulates that response, she noted.

Creech agreed.

“This shouldn’t dissuade us from pursuing a vaccine,” he said. “Antibodies are only a part of the story.”

___

Marilynn Marchione can be followed on Twitter at http://twitter.com/MMarchioneAP

___

The Associated Press Health and Science Department receives support from the Howard Hughes Medical Institute’s Department of Science Education. The AP is solely responsible for all content.

___

This story was updated on July 22, 2020, to correct the half-life of coronavirus antibodies, because of an error made by the researchers. It is 36 days, not 73, according to the lead researcher.

Marilynn Marchione, The Associated Press

Coronavirus

Get local stories you won't find anywhere else right to your inbox.
Sign up here

Just Posted

Mike Ammeter (Photo by Rebecca Hadfield)
Sylvan Lake man elected chair of Canadian Canola Growers Association

Mike Ammeter is a local farmer located near the Town of Sylvan Lake

City of Red Deer has nearly doubled its active COVID-19 case count since Feb. 10 and has 75.6 per cent of the Central zone’s active cases. (File photo)
Another new high: Red Deer hits 574 active COVID-19 cases

Province reports 13 new COVID-19 deaths, 430 new cases

Alberta chief medical officer of health Dr. Deena Hinshaw reported 11 additional deaths over the past 24 hours. (photography by Chris Schwarz/Government of Alberta
Red Deer active COVID-19 cases drop slightly

Province reports 267 additional COVID-19 cases, 11 new deaths

RCMP photo
Lacombe man caught stealing scrap metal in Bonnyville

A male from Edmonton was also arrested

A past production by Cow Patty Theatre. (File Photo)
Lacombe dinner theatre company looking to future with new shows

Cow Patty Theatre is planning its 2021-22 season to being in November

Bookings for COVID-19 vaccines for people age 75 or older start Wednesday. (File photo by THE CANADIAN PRESS)
Updated: Delays for seniors booking for vaccine appointments

By 9:20 a.m. Wednesday, 4,500 seniors had booked their appointments

NDP leader Jagmeet Singh holds a press conference on Parliament Hill in Ottawa on Wednesday, Feb. 24, 2021. THE CANADIAN PRESS/Sean Kilpatrick
NDP will not trigger election as long as pandemic continues: Singh

‘“We will vote to keep the government going’

Students and staff at Gateway Christian School wore pink Wednesday in support of Pink Shirt Day, a worldwide anti-bullying initiative that was started in 2007. (Photo courtesy of Red Deer Public Schools)
Students, central Alberta community celebrate Pink Shirt Day

Mayor of Sylvan Lake Sean McIntyre supports anti-bullying cause

Minister Rick Wilson poses with Katie at the Boys and Girls Club of Wetaskiwin, both wearing her Pink Shirt Day design. Facebook/ Boys and Girls Club of Wetaskiwin.
Wetaskiwin Boys and Girls club Pink Shirt day design focuses on kindness

Katie with the Boys and Girls Club of Wetaskiwin created this year’s Pink Shirt Day design.

Black Press File Photo
Valentine’s Day shooting in Maskwacis leaves one male in hospital, one male in custody

19-year-old Francis Edward Nepoose from Maskwacis has been charged with attempted murder.

Red Deer Court of Queen’s Bench Justice Anne Kirker is expected to sentence Satnam Singh Sandhu on Friday. Red Deer Advocate file photo
Updated: Sylvan Lake man pleads guilty to manslaughter for strangling wife in 2019

Kulvinder Sandhu was strangled and died in hospital several days later

Sentencing delayed in the stabbing death of Samantha Sharpe, of Sunchild First Nation. (Red Deer Advocate file photo)
Central Alberta man not criminally responsible for killing his father in 2020: judge

Psychiatrist testified Nicholas Johnson was psychotic when he killed his father

The cover of “Hometown Asylum: A History and Memoir of Institutional Care.” (Submitted)
Ponoka-born author writes history of old mental hospital

“Hometown Asylum: A History and Memoir of Institutional Care” covers 1911 to 1971

Most Read