• Home
  • Health & Wellness
  • Disclaimer
    • Terms of Use
    • Privacy Policy
    • DMCA Notice
Podcast
  • Home
  • Health & Wellness
  • Disclaimer
    • Terms of Use
    • Privacy Policy
    • DMCA Notice
24/7 Health News
No Result
View All Result
Home Article

Will omicron-specific booster shots be effective at combating COVID-19? 5 questions answered

September 1, 2022
in Article
0
Will omicron-specific booster shots be effective at combating COVID-19? 5 questions answered
file 20220831 4878 mt0k59
In a matter of days, eligible people will be lining up to receive the newly formulated booster shot. filadendron/E+ via Getty Images

On Aug. 31, 2022, the Food and Drug Administration authorized the use of updated COVID-19 booster shots that are specifically tailored to combat the two most recent and contagious omicron subvariants, BA.4 and BA.5. Following the FDA’s emergency use authorization, the Centers for Disease Control and Prevention is expected to endorse the shots, allowing them to be administered within days.

The new booster shots – one by Moderna and another from Pfizer-BioNTech – come as more than 450 people are still dying of COVID-19 every day in the U.S.

_As of Aug. 31, 2022, only 48.5% of booster-eligible people in the U.S. have received their first booster shot, and just under 34% of those eligible have received their second. These low numbers may in part be influenced by people waiting for the newer versions of the vaccines to provide better protection. But booster shots have proven to be an essential layer of protection against COVID-19.

Prakash Nagarkatti and Mitzi Nagarkatti are immunologists who study infectious disorders and how vaccines trigger different aspects of the immune system to fight infection. They weigh in on how the updated booster shots train the immune system and how protective they might be against COVID-19.

Table of Contents

  • 1. What is different about the updated booster shots?
  • 2. How does a bivalent vaccine trigger an immune response?
  • 3. How protective will the new shots be against infection?
  • 4. Will it only be a booster shot?
  • 5. Will the new shots protect against future variants?

1. What is different about the updated booster shots?

The newly authorized shots are the first updates to the original COVID-19 vaccines that were introduced in late 2020. They use the same mRNA technology as the original vaccines. The key difference between the original COVID-19 shots and the new “bivalent” version is that the latter consists of a mixture of mRNA that encodes the spike proteins of both the original SARS-CoV-2 virus and the more recent omicron subvariants, BA.4 and BA.5.

As of late August 2022, the BA.4 and BA.5 omicron subvariants are dominant worldwide. In the U.S., currently 89% of COVID-19 infections are caused by BA.5 and 11% are caused by BA.4.

The inability of the original vaccine strains to prevent reinfection and to trigger long-term protective immunity prompted the need for the reformulated vaccines.

The booster shots target the BA.4 and BA.5 subvariants of the omicron variant, as well as the original version of SARS-CoV-2, the virus that causes COVID-19.

2. How does a bivalent vaccine trigger an immune response?

In an actual COVID-19 infection, the SARS-CoV-2 virus uses its protruding spike protein to latch onto human cells and gain entry into cells. The spike protein triggers the production of so-called neutralizing antibodies, which bind to the spike protein and prevent the virus from invading other cells.

But when the virus mutates, as we know that it does, the antibodies that were previously produced in response to the virus can no longer effectively bind to the newly mutated spike protein. In this respect, the SARS-CoV-2 virus acts like a chameleon – a master of disguise – by changing its body configuration and escaping recognition by the immune system.

The ongoing viral mutations are why antibodies produced in response to the original vaccine strains have over time become less effective at fending off infections by new variants.

The concept of bivalent vaccines aimed at protecting against two different strains of a virus is not new. For instance, Cervarix is an FDA-approved bivalent vaccine that provides protection against two different types of human papillomaviruses that cause cancer.

3. How protective will the new shots be against infection?

There are as of yet no human studies on the efficacy of the new bivalent vaccine at preventing reinfections and providing long-term immune protection.

However, in human clinical trials and laboratory studies, both Pfizer-BioNTech and Moderna found that their initial version of the bivalent vaccine, which was directed against the original SARS-CoV-2 virus and an earlier omicron strain, BA.1, induced a strong immune response and longer protection against both the original strain and the BA.1 variant. In addition, the companies reported that the same early combination generated a significant antibody response against the newest omicron subvariants, BA.4 and BA.5, though this antibody response was lower than that seen against subvariant BA.1.

Based on those results, in spring 2022 the FDA rejected the BA.1 bivalent boosters because the agency felt the boosters may fall short of providing sufficient protection against the newest strains, BA.4 and BA.5, which were by then spreading quickly throughout the U.S. and the world. So the FDA asked Pfizer-BioNTech and Moderna to develop bivalent vaccines specifically targeting BA.4 and BA.5, instead of BA.1.

Because clinical trials are time-consuming, the FDA was willing to consider animal studies and other laboratory findings, such as the ability of antibodies to neutralize the virus, to decide whether to authorize the bivalent boosters.

This decision has stirred up controversy over whether it is appropriate for the FDA to approve a booster without direct human data to support it. However, the FDA has stated that millions of people have safely received the mRNA vaccines – which were originally tested in humans – and that the changes in the mRNA sequences in the vaccines do not affect vaccine safety. Thus, it concluded that the bivalent vaccines are safe and that there is no need to wait for human clinical trials.

It is also noteworthy that influenza vaccines are introduced each year based on prediction of the strain that is likely to be dominant, and such formulations do not undergo new clinical trials.

Based on available evidence from the previous COVID-19 vaccines, we believe it is very likely that the new boosters will continue to offer strong protection from severe COVID-19 leading to hospitalization and death.
But whether they will protect against reinfection and breakthrough infections remains to be seen.

4. Will it only be a booster shot?

The bivalent vaccines can only be used as a booster shot at least two months after the completion of the primary series – or initial required shots – or following a previous booster shot. The Moderna bivalent vaccine is authorized for use in people 18 years of age, while the Pfizer bivalent vaccine is authorized for those 12 years of age and older.

Because of the superiority of the bivalent vaccines, the FDA has also removed the use authorization for the original monovalent Moderna and Pfizer COVID-19 vaccines for booster purposes in individuals 18 years of age and older and 12 years of age and older, respectively.

The new bivalent vaccines contain a lower dose of mRNA, and as such are meant to be used only as boosters and not in people who have never received a COVID-19 vaccination.

5. Will the new shots protect against future variants?

How well the bivalent vaccines will perform in the face of new variants that might arise will depend on the nature of future spike protein mutations.

If it is a minor mutation or set of mutations when compared to the original strain or to omicron variants BA.4 and BA.5, the new shots will provide good protection. However, if a hypothetical new strain were to possess highly unique mutations in its spike protein, then it’s likely that it could once again dodge immune protection.

On the flip side, the successful development of the updated vaccines demonstrates that the mRNA vaccine technology is nimble and innovative enough that – within a couple of months of the emergence of a new variant – it is now likely possible to develop and distribute new vaccines that are tailor-made to fight an emerging variant.

The Conversation

Prakash Nagarkatti receives funding from the National Institutes of Health and the National Science Foundation.

Mitzi Nagarkatti receives funding from the National Institutes of Health.

ShareTweetSharePin
Previous Post

Canada’s low-risk alcohol use guidelines have been slashed to 6 drinks per week. Here’s why.

Next Post

75 Hard: what you need to know before taking on this viral fitness challenge

Next Post
75 Hard: what you need to know before taking on this viral fitness challenge

75 Hard: what you need to know before taking on this viral fitness challenge

Most Read

What causes stuttering? A speech pathology researcher explains the science and the misconceptions around this speech disorder

What causes stuttering? A speech pathology researcher explains the science and the misconceptions around this speech disorder

December 15, 2022
morning back pain

Morning Again Ache Trigger Is Not the Mattress

October 11, 2021
lower back pain relief exercises

5 decrease again ache aid workouts

October 11, 2021
3 years after legalization, we have shockingly little information about how it changed cannabis use and health harms

3 years after legalization, we have shockingly little information about how it changed cannabis use and health harms

October 15, 2021
Nasal vaccines promise to stop the COVID-19 virus before it gets to the lungs – an immunologist explains how they work

Nasal vaccines promise to stop the COVID-19 virus before it gets to the lungs – an immunologist explains how they work

December 14, 2022
bleeding in gum

When The Bleeding in gum Is Severe ?

October 11, 2021
Good Night Sleep

6 Causes of Good Evening Sleep

October 11, 2021

COVID vaccines: how one can pace up rollout in poorer international locations

October 5, 2021
Ten small changes you can make today to prevent weight gain

Ten small changes you can make today to prevent weight gain

October 12, 2021
Support and collaboration with health-care providers can help people make health decisions

Support and collaboration with health-care providers can help people make health decisions

December 16, 2021
Greece to make COVID vaccines mandatory for over-60s, but do vaccine mandates work?

Greece to make COVID vaccines mandatory for over-60s, but do vaccine mandates work?

December 1, 2021

Multiple sclerosis: the link with earlier infection just got stronger – new study

October 12, 2021
News of war can impact your mental health — here’s how to cope

Binge-eating disorder is more common than many realise, yet it’s rarely discussed – here’s what you need to know

December 2, 2022
Nurses’ attitudes toward COVID-19 vaccination for their children are highly influenced by partisanship, a new study finds

Nurses’ attitudes toward COVID-19 vaccination for their children are highly influenced by partisanship, a new study finds

December 2, 2022
Kick up your heels – ballroom dancing offers benefits to the aging brain and could help stave off dementia

Kick up your heels – ballroom dancing offers benefits to the aging brain and could help stave off dementia

January 3, 2023
How hot is too hot for the human body? Our lab found heat + humidity gets dangerous faster than many people realize

How hot is too hot for the human body? Our lab found heat + humidity gets dangerous faster than many people realize

July 6, 2022
The promise of repairing bones and tendons with human-made materials

The promise of repairing bones and tendons with human-made materials

January 4, 2022
As viral infections skyrocket, masks are still a tried-and-true way to help keep yourself and others safe

As viral infections skyrocket, masks are still a tried-and-true way to help keep yourself and others safe

December 14, 2022
How regulatory agencies, not the courts, are imposing COVID-19 vaccine mandates

How regulatory agencies, not the courts, are imposing COVID-19 vaccine mandates

October 24, 2021
Heart disease risk from saturated fats may depend on what foods they come from – new research

Heart disease risk from saturated fats may depend on what foods they come from – new research

November 29, 2021
Late night eating may cause greater weight gain – new research points to why

Late night eating may cause greater weight gain – new research points to why

October 12, 2022

10 Things I Learned During My Body Transformation

October 12, 2021

7 Health Benefits of Sweet Potatoes

October 12, 2021
Nobel prize: how chilli peppers helped researchers uncover how humans feel pain

Nobel prize: how chilli peppers helped researchers uncover how humans feel pain

October 12, 2021
How air filters can make COVID wards safer for patients and staff

How air filters can make COVID wards safer for patients and staff

December 1, 2021
GPs don’t give useful weight-loss advice – new study

GPs don’t give useful weight-loss advice – new study

December 16, 2022
Four ways to avoid gaining weight over the festive period – but also why you shouldn’t fret about it too much

Four ways to avoid gaining weight over the festive period – but also why you shouldn’t fret about it too much

December 22, 2022
Five ways to avoid pain and injury when starting a new exercise regime

Five ways to avoid pain and injury when starting a new exercise regime

December 30, 2022
Why suicide prevention support is crucial for people with fetal alcohol spectrum disorder

Why suicide prevention support is crucial for people with fetal alcohol spectrum disorder

September 28, 2022
Too hot to handle: Climate considerations for youth sport during the hottest years on record

Too hot to handle: Climate considerations for youth sport during the hottest years on record

July 19, 2022
  • Home
  • Health & Wellness
  • Disclaimer

© 2020 DAILY HEALTH NEWS

  • Home
  • Health & Wellness
  • Disclaimer
    • Terms of Use
    • Privacy Policy
    • DMCA Notice

© 2020 DAILY HEALTH NEWS