Tag Archives: Omicron

Omicron BA.5 more virulent and replicates faster, new study in mice finds – Times of India

  1. Omicron BA.5 more virulent and replicates faster, new study in mice finds Times of India
  2. Omicron Sub-Variant ‘BA.5’ Shows Higher Virulence in Early Infection: Study | Weather.com The Weather Channel
  3. Engineered mice reveal how Omicron subvariant BA.5 is more virulent News-Medical.Net
  4. Protective effect of previous infection and vaccination against reinfection with BA.5 Omicron subvariant: a nationwide population-based study in Japan The Lancet
  5. Omicron subvariant BA.5 more virulent, study in mice finds Times of India
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Additive effects of booster mRNA vaccination and SARS-CoV-2 Omicron infection on T cell immunity across immunocompromised states – Science

  1. Additive effects of booster mRNA vaccination and SARS-CoV-2 Omicron infection on T cell immunity across immunocompromised states Science
  2. PLSCR1 is a cell-autonomous defence factor against SARS-CoV-2 infection Nature.com
  3. IL-9 identified as contributor to viral spread and airway inflammation in COVID-19 News-Medical.Net
  4. Enhanced MHC-I Suppression In Omicron Variants: A Key Factor In Sustained Infection Forbes
  5. Antigen test swabs are comparable to nasopharyngeal swabs for sequencing of SARS-CoV-2 | Scientific Reports Nature.com
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Genomic Surveillance for SARS-CoV-2 Variants: Circulation of Omicron Lineages — United States, January 2022–May 2023 | MMWR – CDC

  1. Genomic Surveillance for SARS-CoV-2 Variants: Circulation of Omicron Lineages — United States, January 2022–May 2023 | MMWR CDC
  2. Hybrid immunity in older adults is associated with reduced SARS-CoV-2 infections following BNT162b2 COVID-19 immunisation | Communications Medicine Nature.com
  3. Trained immunity: its role in COVID-19 and potential in preparing for future infectious outbreaks News-Medical.Net
  4. CD62L expression marks SARS-CoV-2 memory B cell subset with preference for neutralizing epitopes Science
  5. Fitness, growth and transmissibility of SARS-CoV-2 genetic variants Nature.com
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Virological characteristics of the SARS-CoV-2 XBB variant derived from recombination of two Omicron subvariants – Nature.com

  1. Virological characteristics of the SARS-CoV-2 XBB variant derived from recombination of two Omicron subvariants Nature.com
  2. Identifying trajectories of the evolution of post-COVID-19 condition News-Medical.Net
  3. Profiling post-COVID-19 condition across different variants of SARS-CoV-2: a prospective longitudinal study in unvaccinated wild-type, unvaccinated alpha-variant, and vaccinated delta-variant populations The Lancet
  4. A retrospective analysis of clinical features of patients hospitalized with SARS-CoV-2 Omicron variants BA.1 and BA.2 | Scientific Reports Nature.com
  5. Novel ‘CLEVER’ method accelerates engineering and genetic study of SARS-CoV-2 and its variants News-Medical.Net
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Convergent evolution of SARS-CoV-2 Omicron subvariants leading to the emergence of BQ.1.1 variant – Nature.com

  1. Convergent evolution of SARS-CoV-2 Omicron subvariants leading to the emergence of BQ.1.1 variant Nature.com
  2. Study may provide new avenues for addressing somatosensory symptoms of long COVID News-Medical.Net
  3. New study suggests that SARS-CoV-2 might induce lasting pain in unique way Medical Xpress
  4. Targetable elements in SARS-CoV-2 S2 subunit for the design of pan-coronavirus fusion inhibitors and vaccines | Signal Transduction and Targeted Therapy Nature.com
  5. Cationic crosslinked carbon dots-adjuvanted intranasal vaccine induces protective immunity against Omicron-included SARS-CoV-2 variants Nature.com
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A novel pan-sarbecovirus vaccine candidate neutralizes Omicron BQ.1.1 and XBB subvariants – News-Medical.Net

  1. A novel pan-sarbecovirus vaccine candidate neutralizes Omicron BQ.1.1 and XBB subvariants News-Medical.Net
  2. Synthetic multiantigen MVA vaccine COH04S1 and variant-specific derivatives protect Syrian hamsters from SARS-CoV-2 Omicron subvariants | npj Vaccines Nature.com
  3. Anti-Omicron antibodies are induced by hypermutation with ancestral BNT162b2 COVID vaccine News-Medical.Net
  4. A new generation Mpro inhibitor with potent activity against SARS-CoV-2 Omicron variants | Signal Transduction and Targeted Therapy Nature.com
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Maternal mRNA covid-19 vaccination during pregnancy and delta or omicron infection or hospital admission in infants: test negative design study – The BMJ

  1. Maternal mRNA covid-19 vaccination during pregnancy and delta or omicron infection or hospital admission in infants: test negative design study The BMJ
  2. COVID vaccination in pregnancy found to protect infants against infection and hospital admission Medical Xpress
  3. Vaccination campaigns can reduce the impact of COVID-19 on pregnant women News-Medical.Net
  4. Protecting infants through covid-19 vaccination during pregnancy The BMJ
  5. COVID-19 vaccination during pregnancy helps protect newborns, Canadian study suggests CBC News
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Breakthrough Omicron BA.1/BA.2 infections in the triple-vaccinated linked to broad-based immunity – News-Medical.Net

  1. Breakthrough Omicron BA.1/BA.2 infections in the triple-vaccinated linked to broad-based immunity News-Medical.Net
  2. Severe SARS-Cov2 pneumonia in vaccinated patients: a multicenter cohort study | Scientific Reports Nature.com
  3. Establishment of a rapid and accurate SARS-CoV-2 antigen detection kit able to identify Omicron mutants News-Medical.Net
  4. New study suggests Omicron BA.1 breakthrough infection drives long-term remodeling of memory B cell repertoire in vaccinated populations News-Medical.Net
  5. Risk factors for Omicron reinfections among previously infected frontline workers in the United States News-Medical.Net
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Information for Persons Who Are Immunocompromised Regarding Prevention and Treatment of SARS-CoV-2 Infection in the Context of Currently Circulating Omicron Sublineages — United States, January 2023

BOX. Prevention measures against SARS-CoV-2 for persons who are immunocompromised, their household members, and close contacts in the context of currently circulating Omicron sublineages — United States, January 2023

Because Evusheld is not currently authorized for preexposure prophylaxis against SARS-CoV-2 infection in the United States, it is important that persons who are moderately to severely immunocompromised,* those who might have an inadequate immune response to COVID-19 vaccination, and those with contraindications to receipt of COVID-19 vaccines, exercise caution and recognize the need for additional preventive measures to protect themselves from SARS-CoV-2 infection. Persons with immunocompromise, their household members, and close contacts can use the following steps and precautions to help prevent SARS-CoV-2 infection and mitigate COVID-19 illness if they become infected.

COVID-19 vaccines, booster doses, and staying up to date*
  • COVID-19 vaccines remain the best way to protect against severe COVID-19. COVID-19 vaccines help the body develop protection against SARS-CoV-2 infection. Although vaccinated persons sometimes get infected with SARS-CoV-2, staying up to date with COVID-19 vaccines significantly lowers the risk for severe illness, hospitalization, or death from COVID-19.
  • CDC recommends that all persons who are eligible, especially those who are immunocompromised or have weakened immune systems, get an updated (bivalent) booster dose and stay up to date with their COVID-19 vaccines.
Personal COVID-19 action plan§
  • Persons should consider how to protect themselves and others around them should they become ill with COVID-19 or if the community COVID-19 transmission level changes. The plan should include:
    • ways to protect oneself and others including considerations in case of illness, such as finding a room in which to isolate
    • actions to take in case of exposure or symptom onset
    • what to do in the event of receipt of a positive SARS-CoV-2 test result
  • Persons should share their COVID-19 plan with their family, friends, and health care providers so they can support prevention and preparation steps. CDC suggests that persons consider how others can help them if they get ill. It is important to adhere to treatment plans, keep routine health care appointments, and ensure that prescriptions are filled. Persons should make alternative plans for work, child care, and other responsibilities that might cause stress if they become ill.
Masks or respirators
  • Masks are made to contain droplets and particles that persons breathe, cough, or sneeze. A variety of masks are available. Some masks provide a higher level of protection than others. Wearing a mask with the best fit and comfort provides the best protection.**
  • Respirators (e.g., N95 and NIOSH-approved KN95) provide higher protection than masks.†† Respirators are made to protect persons by fitting closely on their face to filter out particles, including SARS-CoV-2. They can also block droplets and particles that a person breathes, coughs, or sneezes out to limit transmission to others. NIOSH approves many types of filtering facepiece respirators. The most widely available are N95 respirators, but other types (N99, N100, P95, P99, P100, R95, R99, and R100) offer the same or better protection as an N95 respirator.
Physical distancing
  • Small particles that persons breathe out can contain virus particles. The closer a person is to other persons, the higher the risk for exposure to SARS-CoV-2. Persons can minimize risk of exposure by avoiding indoor crowded areas or maintaining a ≥6 ft (1.8 m) distance from others. Such actions must be balanced against risks of avoiding such activities.
Ventilation§§
  • Opening windows and doors to bring as much fresh air into the home as possible (weather permitting) can improve ventilation.
  • Portable high-efficiency particulate air cleaners are useful if a home is not outfitted with an HVAC system.
  • Exhaust fans and other fans can improve air flow.
  • In homes where the HVAC fan operation can be controlled by a thermostat, the fan should be set to the “on” position instead of “auto” when others are visiting. This allows the fan to run continuously, even if heating or air conditioning is not on, to ensure the HVAC system provides continuous airflow and filtration.
Time outdoors
  • Spending time outdoors, when possible, instead of indoors, can also help reduce transmission. Viral particles spread between persons more readily indoors than outdoors.
Handwashing
  • Frequent handwashing with soap and water, preferably, or using a hand sanitizer that contains ≥60% alcohol can reduce risk for many illnesses, including COVID-19.
Testing for SARS-CoV-2¶¶
  • Persons should get tested if they have COVID-19 symptoms. Viral tests are used for SARS-CoV-2 detection. There are two types of viral tests: rapid tests and laboratory tests. These tests might use nasal, throat, or saliva samples. Persons can take actions to reduce further transmission if they are aware of their SARS-CoV-2 infection.
  • Free at-home tests*** are available. Persons should check with their health insurance, Medicaid, or Medicare plan to learn what tests are available.††† Persons with a disability can receive help from the Disability Information and Access Line§§§ to access a test or identify an accessible test location.
  • Persons should be aware of free or low-cost testing locations¶¶¶ that are near their homes.
COVID-19 Treatment****
  • Persons should contact their health care provider, health department, or community health center†††† to learn about treatment options. Treatment must be started within 5–7 days after symptoms develop to be effective.
  • Community Test to Treat locations§§§§ can be accessed if or when persons cannot reach their health care provider or do not have one. These sites offer testing and prescriptions from a health care provider (either onsite or by telehealth) and dispense medications.
  • Antiviral treatments are available for persons with mild to moderate COVID-19 symptoms who are at high risk for progression to severe disease, hospitalization, and death. Persons are at high risk of disease if they
    • are aged ≥50 years
    • have an underlying health condition,¶¶¶¶ especially moderate to severe immunosuppression
    • are unvaccinated
  • Persons who are immunocompromised should discuss a treatment plan with their doctor and identify which COVID-19 treatment would be best for them. Some persons with COVID-19 who are immunocompromised or receiving immunosuppressive treatment might benefit from a convalescent plasma treatment.*****
  • CDC recommends that immunocompromised persons with COVID-19 isolate for ≥10 days and check with their health care provider before ending isolation.†††††

Abbreviations: HVAC = heating, ventilation, and air conditioning; NIOSH = National Institute for Occupational Safety and Health.

* https://www.cdc.gov/coronavirus/2019-ncov/vaccines/stay-up-to-date.html

https://www.cdc.gov/coronavirus/2019-ncov/need-extra-precautions/people-with-medical-conditions.html

§ https://www.cdc.gov/coronavirus/2019-ncov/downloads/needs-extra-precautions/FS_COVID_Plan_FINAL.pdf

https://www.cdc.gov/coronavirus/2019-ncov/prevent-getting-sick/types-of-masks.html

** Persons who are deaf or hard of hearing may request a clear mask to assist with lipreading or seeing facial expressions. Persons with sensory disorders or intellectual and developmental disabilities might be unable to wear masks and should consider face shields.

†† Persons with severe respiratory impairment (e.g., shortness of breath with minimal exertion or supplemental oxygen use) should consult with a health care provider regarding N95 respirator usage. Some N95 respirators might contain latex. Persons with natural rubber latex allergies should consult the manufacturer’s website for information about the specific model.

§§ https://www.cdc.gov/coronavirus/2019-ncov/prevent-getting-sick/Improving-Ventilation-Home.html; https://www.cdc.gov/coronavirus/2019-ncov/community/ventilation.html

¶¶ https://www.cdc.gov/coronavirus/2019-ncov/symptoms-testing/testing.html

*** https://special.usps.com/testkits

††† https://www.cms.gov/how-to-get-your-at-home-OTC-COVID-19-test-for-free

§§§ https://acl.gov/DIAL

¶¶¶ https://www.hhs.gov/coronavirus/community-based-testing-sites/index.html

**** https://www.cdc.gov/coronavirus/2019-ncov/your-health/treatments-for-severe-illness.html

†††† https://data.hrsa.gov/data/reports/datagrid?gridName=FQHCs

§§§§ https://covid-19-test-to-treat-locator-dhhs.hub.arcgis.com/

¶¶¶¶ https://www.cdc.gov/coronavirus/2019-ncov/hcp/clinical-care/underlyingconditions.html

***** https://www.fda.gov/media/136798/download

††††† https://www.cdc.gov/coronavirus/2019-ncov/your-health/isolation.html

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Even bivalent updated COVID-19 boosters struggle to prevent omicron subvariant transmission – an immunologist discusses why new approaches are necessary

By almost any measure, the vaccination campaign against SARS-CoV-2, the virus that causes COVID-19, has been a global success.

As of January 2023, more than 12 billion vaccines against SARS-CoV-2 have been administered in an effort that has saved countless lives – more than 14 million in the first year of vaccine availability alone. With a 95% efficacy in the prevention of severe infection and death, and better safety profiles than similar historically effective vaccines, the biomedical community hoped that a combination of vaccination and natural immunity might bring the pandemic to a relatively quick end.

But the emergence of new viral variants, particularly omicron and its array of subvariants, upended those expectations. The latest omicron strain, XBB.1.5. – dubbed “Kraken”, after a mythical sea creature – has rapidly become the dominant subvariant in the U.S. The World Health Organization is calling it the most contagious strain so far, with its success almost certainly attributable to an ability to dodge immunity from previous vaccines or infections.

The effort to get ahead of these ever-changing variants is also in part what has led the Food and Drug Administration to reconsider its approach to COVID-19 vaccination. On Jan. 23, 2023, the agency proposed that current guidelines for a series of shots followed by a booster be replaced by an annual COVID-19 vaccine that is updated each year to combat current strains. The proposal is set to be reviewed by the FDA’s science advisory committee on Jan. 26.

Limitations of current mRNA vaccination strategies

Unfortunately, the new bivalent shots, which include components from both the original SARS-CoV-2 strain as well as a recent omicron variant, have not performed as well as some scientists had hoped. Although there is no question that the updated jabs are capable of boosting antibody levels against SARS-CoV-2 and helping to prevent severe illness and hospitalization, several studies have suggested that they are not necessarily more capable of preventing omicron infections than their predecessors.

As an immunologist who studies how the immune system selects which antibodies to produce and immune responses to COVID-19, these new results are disappointing. But they are not entirely unexpected.

When COVID-19 vaccines were being rolled out in early 2021, immunologists began having public discussions about the potential obstacles to rapidly generating updated vaccines to emerging viral strains. At the time, there was no hard data. But researchers have known for a very long time that immunological memory, the very thing that offers continued protection against a virus long after vaccination, can sometimes negatively interfere with the development of slightly updated immune responses.

The failure of these new bivalent vaccines in widely preventing omicron infections suggests that our current approach is simply not sufficient to interrupt the viral transmission cycle driving the COVID-19 pandemic. In my view, it’s clear that innovative vaccine designs capable of producing a broader immunity are badly needed.

Vaccines are designed to generate immune memory

In simplest terms, vaccines are a way to give your immune system a sneak peek at a pathogen. There are several different ways to do this. One way is to inject inactivated versions of a virus, as has been done with polio. Another is to use noninfectious viral components, such as the proteins used for flu vaccines.

And most recently, scientists have found ways to deliver mRNA “instructions” that tell your body how to make those noninfectious viral components. This is the approach used with the Moderna and Pfizer vaccines targeted against COVID-19.

The mRNA-based vaccines all train your immune system to identify and respond against critical components of a potential invader. An important part of that response is to get your body to produce antibodies that will hopefully prevent future infections, helping to break the cycle of person-to-person transmission.

In a successful response, the immune system will not only produce antibodies that are specific to the pathogen, but will also remember how to make them in case you encounter that same pathogen again in the future.

The existing approach to COVID-19 vaccines has proved effective at preventing serious illness and death, but it has not prevented infections as well as scientists had hoped. Morsa Images/DigitalVision via Getty Images

The specter of ‘original antigenic sin’

But what happens when the virus evolves and that memory becomes obsolete?

Immunologists have wondered this since the initial COVID-19 vaccine rollout. Recently, it has found new relevance in light of the FDA’s proposal for an updated annual COVID-19 shot.

While it is possible that immune responses to updated vaccines will simply replace the old ones, that has not been true for influenza. With flu, researchers have learned that preexisting immunity to one strain can actively inhibit the ability to respond well against another.

Put in everyday language, think of a virus as a car trying to run you over. You might produce one kind of antibody against the hood, one against the bumper and one against the hubcaps that prevents the wheels from turning. You have produced three kinds of antibodies specific to the car, but it turns out that only the hubcap antibodies effectively slow it down.

Now the car mutates, like SARS-CoV-2 has. It changes the shape of the hubcaps or it removes them altogether. Your immune system still recognizes the car, but not the hubcaps. The system doesn’t know that the hubcap was the only effective target, so it ignores the hubcaps and ramps up its attack on the hood and bumper.

In ignoring the new hubcap response, the immune system’s memory of the original car is not only obsolete, but it is also actively interfering with the response necessary to target the new car’s wheels. This is what immunologists call “original antigenic sin” – ineffective immune memory that hampers desired responses to new pathogen strains.

This sort of interference has been extremely difficult to quantify and study in humans, although it may become easier with the FDA’s proposal. A once-yearly approach to COVID-19 vaccination opens the door for more straightforward studies on how memory to each vaccine influences the next.

Multi-strain vaccinations offer hope

Simultaneously, significant efforts are being made to prioritize the pursuit of a single-shot or “universal” vaccine. One approach has been to take advantage of emerging research showing that if your immune system is presented with multiple versions of the same pathogen, it will tend to choose targets that are shared between them.

Presented with a Model T, Ford F-150 and electric Mustang all at once, your immune system will often choose to ignore differences like the hubcaps in favor of similarities like the shape and rubber on the tires. Not only would this interfere with the function of all three vehicles, but it could theoretically interfere with most road-based vehicles – or viral threats such as variants.

Researchers have begun making rapid headway using this approach with the development of complex multi-strain flu vaccines that are performing well in early clinical trials. New studies focused on SARS-CoV-2 hope to do the same. Persistent pathogens including influenza and HIV all suffer from versions of the same antibody-targeting issues. It is possible that this pandemic may serve as a crucible of innovation that leads to the next generation of infectious disease prevention.

This is an updated version of an article originally published on March 8, 2021.

This article is republished from The Conversation, an independent nonprofit news site dedicated to sharing ideas from academic experts. If you found it interesting, you could subscribe to our weekly newsletter.

It was written by: Matthew Woodruff, Emory University.

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Matthew Woodruff does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.

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