Saturday, October 16, 2021
ADVT 
International

How long does protection from COVID-19 vaccines last?

Darpan News Desk The Canadian Press, 22 Apr, 2021 10:18 PM
  • How long does protection from COVID-19 vaccines last?

How long does protection from COVID-19 vaccines last?

Experts don't know yet because they're still studying vaccinated people to see when protection might wear off. How well the vaccines work against emerging variants will also determine if, when and how often additional shots might be needed.

“We only have information for as long as the vaccines have been studied," said Deborah Fuller, a vaccine researcher at the University of Washington. “We have to study the vaccinated population and start to see, at what point do people become vulnerable again to the virus?”

So far, Pfizer's ongoing trial indicates the company's two-dose vaccine remains highly effective for at least six months, and likely longer. People who got Moderna’s vaccine also still had notable levels of virus-fighting antibodies six months after the second required shot.

Antibodies also don't tell the whole story. To fight off intruders like viruses, our immune systems also have another line of defence called B and T cells, some of which can hang around long after antibody levels dwindle. If they encounter the same virus in the future, those battle-tested cells could potentially spring into action more quickly.

Even if they don't prevent illness entirely, they could help blunt its severity. But exactly what role such “memory” cells might play with the coronavirus -- and for how long -- isn’t yet known.

While the current COVID-19 vaccines will likely last for at least about a year, they probably won’t offer lifelong protection, as with measles shots, said Dr. Kathleen Neuzil, a vaccine expert at the University of Maryland School of Medicine.

“It’s going to be somewhere in the middle of that very wide range,” she said.

Variants are another reason we might need an additional shot.

The current vaccines are designed to work against a particular spike protein on the coronavirus, said Mehul Suthar of the Emory Vaccine Center. If the virus mutates enough over time, vaccines might need to be updated to boost their effectiveness.

So far, the vaccines appear protective against the notable variants that have emerged, though somewhat less so on the one first detected in South Africa.

If it turns out we need another shot, a single dose could extend protection of the current shots or contain vaccination for one or more variants.

The need for follow-up shots will also depend partly on the success of the vaccination push globally, and tamping down transmission of the virus and emerging variants.

MORE International ARTICLES

Biden hints at more vaccine help for Canada

Biden hints at more vaccine help for Canada

The U.S. has already provided Canada with about 1.5 million doses of the AstraZeneca vaccine, and gave 2.5 million doses to Mexico.

Biden hints at more vaccine help for Canada

DOJ to investigate police practices in Minneapolis

DOJ to investigate police practices in Minneapolis

Attorney General Merrick Garland says the investigation will look into the department's use of force and whether it engaged in discriminatory practices.

DOJ to investigate police practices in Minneapolis

UPDATE: The names of the victims killed in the Indianapolis shooting released, half of them Sikhs

UPDATE: The names of the victims killed in the Indianapolis shooting released, half of them Sikhs

Police did not release the names of those who were injured and taken to hospital. The Sikh Coalition and the Sikh Community reeling from the loss of their loved ones and sharing their grief condemning this senseless act of violence over social media posts. 

UPDATE: The names of the victims killed in the Indianapolis shooting released, half of them Sikhs

Majority of employees killed and wounded in shooting at a FedEx facility in Indianapolis from the Sikh Community

Majority of employees killed and wounded in shooting at a FedEx facility in Indianapolis from the Sikh Community

According to Indiana police the motive of the gunman on opening fire Thursday night at a FedEx processing centre near the Indianapolis airport is not known. The shooter started randomly firing at people in the parking lot and then went into the building and continued shooting. 

Majority of employees killed and wounded in shooting at a FedEx facility in Indianapolis from the Sikh Community

US recommends 'pause' for J&J vaccine

US recommends 'pause' for J&J vaccine

More than 6.8 million doses of the J&J vaccine have been administered in the U.S., the vast majority with no or mild side effects.

US recommends 'pause' for J&J vaccine

Serving Humanity At No Cost

Serving Humanity At No Cost

The purpose of this hospital is to serve humanity; Sikhs are known for this, we are doing this for years. Soon you will see, this will not be just India’s but the world’s largest kidney dialysis hospital.

Serving Humanity At No Cost

PrevNext