Tag: Covid-19

Single Administration Therapeutic Interfering Particle (TIP) Reduces Covid-19 Viral Shedding & Pathogenesis in Hamsters

Proceedings of the National Academy of Sciences (PNAS) recently published a study showing:

Abstract

“The high transmissibility of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a primary driver of the COVID-19 pandemic. While existing interventions prevent severe disease, they exhibit mixed efficacy in preventing transmission, presumably due to their limited antiviral effects in the respiratory mucosa, whereas interventions targeting the sites of viral replication might more effectively limit respiratory virus transmission. Recently, intranasally administered RNA-based therapeutic interfering particles (TIPs) were reported to suppress SARS-CoV-2 replication, exhibit a high barrier to resistance, and prevent serious disease in hamsters. Since TIPs intrinsically target the tissues with the highest viral replication burden (i.e., respiratory tissues for SARS-CoV-2), we tested the potential of TIP intervention to reduce SARS-CoV-2 shedding. Here, we report that a single, postexposure TIP dose lowers SARS-CoV-2 nasal shedding, and at 5 days postinfection, infectious virus shed is below detection limits in 4 out of 5 infected animals. Furthermore, TIPs reduce shedding of Delta variant or WA-1 from infected to uninfected hamsters. Cohoused “contact” animals exposed to infected, TIP-treated animals exhibited significantly lower viral loads, reduced inflammatory cytokines, no severe lung pathology, and shortened shedding duration compared to animals cohoused with untreated infected animals. TIPs may represent an effective countermeasure to limit SARS-CoV-2 transmission.”

Is Treatment with Antibodies a Substitute for Vaccination for Covid-19?

I read the news article about scientists publishing a study which shows it’s possible to make antibodies that may neutralize most of the Covid-19 variants. I read this after failing to find any local facility in my area that has the updated bivalent Covid-19 vaccine booster available yet. Sena and I plan to get the booster, which would be our 5th shot.

I don’t have a clue how to evaluate the study itself, which was published in an Open Access journal, Communications Biology. I didn’t understand the peer reviewers’ comments and suggestions because I lack the scientific background to make sense of them.

I was under the impression that using antibodies for Covid-19 has to be prompted by getting infected first. In fact, the lead author of the study actually points out in the news article in published in the Jerusalem Post,

“In our view, targeted treatment with antibodies and their delivery to the body in high concentrations can serve as an effective substitute for repeated boosters, especially for at-risk populations and those with weakened immune systems. COVID-19 infection can cause serious illness, and we know that providing antibodies in the first days following infection can stop the spread of the virus.

“It is, therefore, possible that by using effective antibody treatment, we will not have to provide booster doses to the entire population every time there is a new variant,” Freund concluded.

I understand that immunity wanes after vaccination and that’s frustrating because apparently you need another booster every few months.

But I’m not sure I see how the antibody treatment would be a replacement for vaccines, if that’s the implication.

The interventions sound complementary. Wouldn’t it be better to have vaccine-induced immunity and use the antibodies as a backup treatment when you get infected?

I got the impression from reading about monoclonal antibody treatments that they have to be administered by infusions in specialty clinics. And you have to catch it in the first few days. And the indication for it is getting infected with the virus—which I thought could be avoided in the first place by getting vaccinated.

The plan now seems to be to manufacture vaccines annually to target important variants of Covid-19, similar to what we’ve been doing for influenza. We’ve been getting flu shots every year for a long time. Maybe we won’t need to get boosters every few months.

It makes sense to use antibodies for immunocompromised persons, though, because they don’t respond as well to vaccines.

Why would we “substitute” monoclonal antibody infusions administered in clinics to treat infections for vaccines which can prevent severe disease and death?

I’m not knocking the study; I’m just a retired psychiatrist, not an infectious disease scientist. Am I missing something?

CDC ACIP Meeting Today and Tomorrow: Covid-19 Vaccine Omicron Bivalent Booster Candidates

The CDC ACIP will meet today and tomorrow about the Covid-19 Vaccine Omicron Bivalent Booster candidates from Pfizer and Moderna. A vote is expected this afternoon.

Update: The committee voted by a majority to upvote the approval of the Pfizer and Moderna bivalent boosters this afternoon. There was one dissenting vote because there was no clinical data to present. There was a clinical study using the bivalent vaccine booster, but results would not have been available until November or December.

However, there was a complicated statistical predication model which showed that if the boosters were rolled out this month, many thousands of hospitalizations and deaths could be prevented as opposed to waiting a few more months. That got prioritized in order to approve the boosters now rather than wait for the clinical study results.

There was a lot of concern about the packaging of the boosters resembling other boosters which might lead to mistakes in administration. Pfizer has a booster vial that looks very similar to that of their bivalent Omicron booster, unless you closely read the tiny print on the vial which says it’s BA.4/BA.5.

The committee voted to cancel tomorrow’s meeting since they completed the goal today.

CDC ACIP Meeting for September 1-2 on Bivalent Omicron Covid-19 Vaccine Boosters

The CDC ACIP have an agenda posted indicating that the advisory committee will discuss Covid-19 Bivalent Omicron vaccine candidates on September 1-2, 2022. A vote is scheduled on September 1, 2022.

FDA Removes N95 Respirators from Shortage List

I think it’s ironic that about the same time a PLOs One study and news articles came out announcing a new method using 8-inch rubber bands for improving the fit of the surgical mask to approximate that of the N95 respirator, the FDA removed the N95 respirator from the medical device shortage list. This is relevant to help protect people from infection with Covid-19 because even vaccinated older people are getting hospitalized with the Omicron variant of the virus.

I’m not saying that the new rubber band method to tighten the fit of the surgical mask is not an improvement. It might come in handy when there is another shortage of N95 respirators.

The method mainly targets health care professionals. It would be difficult to persuade everyone in the community to adopt the technique. It’s tough enough to get people to wear masks even in crowded buildings in high transmission areas.

This is despite the CDC study showing that the elderly population continue to be at high risk for hospitalization from Covid-19 despite being vaccinated with the initial series and one or more boosters.

I think it’s hard to achieve a good fit even with the N95 respirators. The free ones distributed by the Federal government early this year were not widely available and fit poorly because the straps were elastic (similar to rubber bands, only flimsier) and loosened quickly, even after using only 2 or 3 times. At least the ones I got did. Prior to retiring, I was never able to pass a Fit test at the hospital using that type of mask.

I think my surgical masks fit better than the N95 respirators, especially after using the knot and tuck method to get a tighter seal.

Now the newer rubber band method to get a better seal uses two large 8-inch rubber bands to make the mid-face portion of the mask fit closer to your face. It looks a little easier to do than the earlier 3 rubber band technique developed a couple of years ago. That one was even tested at the University of Iowa Hospitals and Clinics by emergency room health care professionals, resulting in a small published study (the “double eights mask brace”).

All of the rubber band mask braces techniques were a response to the shortage of N95 respirators. What’s interesting to me is that, as the authors of the PLOs One study point out, there is a fair amount of variability in how well the N95 mask fits. Differences in the shape of a person’s face can account for some of this.

And there’s no shortage of N95 respirators—for now, at least according to the FDA.

If a non-health care professional wanted to use a rubber band brace, it would take some practice to get a good seal. There’s a bit of a learning curve even for a pro.

I think it would be difficult to persuade the average person to get the rubber bands and the surgical mask out of a pocket or a purse and fiddle around to achieve a good fit if you’re just going to run into Wal Mart—where I could not find that the big 8-inch rubber bands are even in stock. They’re pretty much a “3-day shipping” kind of item and could cost as much as $20 a bag.

Covid-19 Vaccine Immune Response to Omicron Wanes According to NIH

According to the National Institute of Health (NIH) the current Covid-19 vaccine booster elicits a robust immune response, it wanes quickly against the Omicron variant.

FDA Advisory Committee Green Lights Novavax Covid-19 Vaccine

The FDA Advisory Committee endorsed the Novavax Covid-19 Vaccine at their meeting June 7, 2022. It awaits the FDA Director’s decision and, if endorsed by the director, would next go to the CDC Advisory Committee for their evaluation, which looks like it might be scheduled later this month.

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