Omicron’s Mutations Impaired Vaccine Effectiveness, CDC Says

Authors: Madison Muller  August 25, 2022 Bloomberg

Almost 40% of people hospitalized in the US with the Covid subvariant that circulated this spring were vaccinated and boosted, highlighting how new strains have mutated to more readily escape the immunity offered by current shots.

The findings from scientists at the US Centers for Disease Control and Prevention underscore the importance of having Covid shots that are better at targeting omicron subvariants. 

From the end of March through May, when the omicron BA.2 and BA.2.12.1 subvariants were dominant in the US, weekly hospitalization rates increased for all adults — with those over 65 hit the hardest. Even so, the total number of hospitalizations remained much lower than when the delta variant was rampant last fall. 

The overall number of hospitalizations is an important point, said Abraar Karan, an infectious disease doctor at Stanford University.

“When you look at who’s hospitalized, it’s much more likely that they will have been vaccinated because so many people are vaccinated now,” Karan said. “The real comparison is how many hospitalizations do we have now versus in the past when people were not vaccinated or not up-to-date with boosters.”

CDC scientists found that vaccines and boosters did a better job of keeping people with delta infections out of the hospital than those with later variants. Effectiveness decreased slightly with the BA.1 variant, then changed significantly with BA.2 — with a much greater share of hospitalized adults who had been vaccinated with at least one booster. 

Read more: Retiring Fauci expected Covid to be ‘behind us’

Immunity from vaccines starts to wane within six months, so staying up-to-date with shots is key to being fully protected. Fewer than half of Americans have gotten a booster shot.

Adults with at least two booster shots fared better than other people when BA.2 was dominant. The majority of those admitted to the hospital also had at least one underlying condition. Unvaccinated adults were more than three times as likely to be hospitalized, but breakthrough infections still represented a significant number of the severe Covid cases, the data show.

US regulators have pushed Moderna Inc., Pfizer Inc. and BioNTech SE to expedite development of omicron-specific boosters for a September rollout. The drugmakers this week submitted early data to the US Food and Drug Administration seeking emergency clearance for updated shots that target the BA.4 and BA.5 virus strains. Scientists and vaccinemakers are already beginning to look toward next-generation shots that may provide longer-lasting protection against more variants. 

The new report’s findings also indicate that along with vaccination, other pharmaceutical and non-pharmaceutical measures should be used by those at highest risk of getting Covid. That includes easy access to therapeutics such as Pfizer’s antiviral drug Paxlovid and Gilead Sciences’ remdesivir, as well as AstraZeneca’s Evusheld for immunocompromised people. Scientists also note that wearing a mask can help guard the wearer from getting sick.  

Though the number of Covid deaths is the lowest it has been since last July, the US continues to see hundreds of deaths each day from Covid, CDC data show.

Pfizer-BioNTech Vaccine Much Weaker in Kids Against Omicron and More

Authors: Mark Terry Published: Mar 01, 2022  BIOSPACE

Pfizer-BioNTech Vaccine Only 12% Effective Against Omicron in 5-11-Year-Olds 

In a new study that is yet to be peer-reviewed, the New York State Department of Health found that the PfizerBioNTech vaccine was only about 12% effective for children ages 5 to 11 years against the Omicron variant. In that age group, it was about 68% effective against Delta, but the effectiveness dropped significantly during the Omicron surge from Dec. 13, 2021, to Jan. 24, 2022. Protection against hospitalization also plummeted from 100% to 48% in the same period. 

The authors of the report think this drop may be the result of the lower dosage the children received. They were dosed with two 10-microgram shots, compared to 30-microgram doses for children 12 to 17 years of age.  

“Given rapid loss of protection against infections, these results highlight the continued importance of layered protections, including mask-wearing, for children to prevent infection and transmission,” the authors wrote. 

Pfizer-BioNTech Vaccine Integrates into Liver Cells in Cell Cultures 

Researchers at Lund University in Sweden conducted research into the Pfizer-BioNTech COVID-19 vaccine and human liver cell lines to determine what kind of effect the vaccine might have on liver cells. The research was published in Current Issues in Molecular Biology. The authors, noting the safety and efficacy of the vaccine against COVID-19, also point out that long-term studies have not been conducted. They note pharmacokinetics data provided by Pfizer to the European Medicines Agency (EMA) showed that the “injection site and the liver were the major sites of distribution, with maximum concentrations observed at 8-48 hours post-dose.

Furthermore, in animals that received the BNT162b2 injection, reversible hepatic effects were observed, including an enlarged liver, vacuolation, increased gamma-glutamyl transferase levels, and increased levels of aspartate transaminase (AST) and alkaline phosphatase (ALP).” They add that transient liver effects caused by the lipid nanoparticle (LNP) delivery systems used with mRNA vaccines have been previously reported, although LNP with no mRNA in it doesn’t cause any significant liver injury. 

Working with the specific human liver cell line Huh7 and the Pfizer-BioNTech vaccine, they found that the vaccine was able to enter the cell line as quickly as six hours after exposure. They cite a report saying some people who received the vaccine developed autoimmune hepatitis, and they question if the human liver cells, integrating the vaccine mRNA, produce SARS-CoV-2 spike protein that then catches the attention of the body’s immune system, inadvertently attacking the liver.

However, there does not appear to have been many other cases of this happening, which would make it extremely rare, assuming it was actually caused by the vaccine and not something else. 

The researchers note, “At this stage, we do not know if DNA reverse transcribed from BNT162b2 is integrated into the cell genome. Further studies are needed to demonstrate the effect of BNT162b2 on genomic integrity, including whole genome sequencing of cells exposed to BNT162b2, as well as tissues from human subjects who received BNT162b2 vaccination.” 

Adamis’ COVID-19 Trial Surpasses Enrollment Expectations 

San Diego-based Adamis Pharmaceuticals reported that due to the acceleration of enrollment in its Phase II/III study for Tempol for COVID-19, its Data Safety Monitoring Board (DSMB) decided the study could continue. No safety or clinical problems were observed. The data from the first 50 participants will be reviewed again in March as part of the first planned interim analysis. 

Tempol has strong, broad in vitro anti-cytokine activity, and in animal studies, appeared to have anti-inflammatory effects in the lungs. 

“We are pleased with the progress of the trial, which has already exceeded the required number of subjects (124) for the second planned interim DSMB analysis,” said Dr. Dennis J. Carlo, president and CEO of Adamis. “We appreciate the feedback from the DSMB. Following the first planned interim analysis, if the DSMB advises for the study to continue, we will also report on the second planned DSMB review following its completion, which may provide additional insight into the safety and clinical results at that time.” 

Here’s Why Viral Vector Vaccines Don’t Alter DNA

— It’s pretty simple — they can’t

Authors: by Veronica Hackethal, MD, MSc, Enterprise & Investigative Writer, MedPage Today March 12, 2021

Adenoviral vector vaccines have been in development for decades, but very few have been approved for use in humans. What does the history of adenoviral vector vaccine development tell us about their safety and their potential to alter DNA?

How Do Adenoviral Vector Vaccines Work?

Essentially, these types of vaccines act like delivery shuttles. They use an adenovirus — which has been engineered to be incapable of replicating and causing disease — to deliver the genes for making the antigen; in this case, that’s the SARS-CoV-2 spike protein. That in turn elicits an immune response and provides protection against the coronavirus.

Adenoviruses are basically common cold viruses that can cause illnesses ranging from cold-like symptoms to bronchitis, gastroenteritis, and conjunctivitis.

“I think people are unfortunately familiar with adenoviruses … [A]t far too many points, you know, you’ve had the sniffle. You’ve had the cough. You felt crummy. If it’s a cold it’s often adenovirus,” Daniel Griffin, MD, PhD, said on a recent episode of MedPage Today‘s “Track the Vax” podcast. Griffin is chief of infectious disease at ProHEALTH Care, an Optum unit.

Humans are infected with multiple different types of adenoviruses throughout their lifetimes. Most serotypes cause mild illness, although adenovirus serotype 7 has been associated with more severe illness. Older adults and people who are immunocompromised or have pre-existing respiratory or cardiac disease may have worse illness.

Precisely because adenoviruses are so common, one problem with using them in vaccines is that people may already have antibodies to them, overwhelming them before they can do their assigned work. Researchers get around that issue by using adenoviruses that humans are unlikely to have encountered before.

Currently, five adenovirus vector vaccines for COVID-19 are in use worldwide.

Each works on the same basic principle, although delivery platforms differ. The AstraZeneca/Oxford vaccine uses the ChAdOx1 platform, which is based on a modified version of a chimpanzee adenovirus.

The Johnson & Johnson vaccine uses a proprietary AdVac platform, made up of a recombinant human adenovirus (adv26). It’s the same platform used in the company’s Ebola virus vaccine (which is approved in Europe) and its investigational Zika, RSV, and HIV vaccines.

Russia’s Sputnik V uses recombinant human adenoviruses Ad26 and Ad5 for the first and second doses, respectively. Finally, China’s CanSino vaccine uses the recombinant human adenovirus Ad5.

For More Information: https://www.medpagetoday.com/special-reports/exclusives/91604

What Do We Really Know About Adenovirus Vectors for Vaccines?

Authors: By Serena Marshall and Lara Salahi February 24, 2021

— The newest COVID shot uses an existing technology but one with lingering questions

As the U.S. hits the half-million death mark from COVID-19 — a grim milestone that is equal to roughly the entire population of Atlanta and more than that of Miami — a new weapon is being added to the COVID-19 vaccine arsenal.

Johnson & Johnson is seeking emergency use authorization for what would become the U.S.’s first one-dose and non-mRNA COVID vaccine. It employs adenovirus vectors, a technology that has been used in labs for decades and was approved for the Ebola vaccine by the FDA in December 2019. It’s the same technology that AstraZeneca/Oxford and Sputnik V use.

Still, questions remain on how these vaccines may be different than mRNA or similar enough to other existing shots to encourage vaccine uptake. To explain how adenovirus vectors work and what to expect from the new products.

For More Information: https://www.medpagetoday.com/podcasts/trackthevax/91323