delta variant – Pediatric Infection Connection

Whirlwind Week

Bud WiedermannDecember 19, 2021Leave a comment

Somebody pushed the reset button this past week. Although we don't yet have the weekly variant reports from CDC (they are published on Tuesdays) it is very clear from just my small world at Children's National Hospital that omicron has hit with a vengeance. I was speaking in the hallway on Friday with my longtime friend and esteemed colleague Dr. Larry D'Angelo who likened what we are seeing to the early situation in South Africa where omicron increased exponentially even while delta was still very much present. An important caveat, however: it's risky to make too much out of day-to-day data, many factors affect case rates and sometimes we can be misled by "hot off the presses" numbers.

A Triple Whammy Ahead?

Most winters in pre-pandemic times I kept my fingers crossed that we would not have our RSV and influenza seasons occur concurrently; the few years we had a double whammy like that it really strained our resources. This winter could be worse. The good news is that although RSV is still around it seems to be on a downward trend. However, influenza A numbers have been increasing both at Children's National and nationally, suggesting we will hit full-blown flu season soon. The second and third components of the trifecta are delta and omicron. If we see all 3 of these viruses causing infections in large numbers at the same time it will be very tough. One silver lining of the omicron era is that it may stimulate more individuals to seek out primary series and booster vaccinations. Also, with school winter break and perhaps a bit more caution on the part of the public, we might have less viral circulation the next couple of weeks. We'll see.

For now clinicians should remember we have two effective influenza antiviral medications, oseltamivir (Tamiflu) and baloxivir marboxil (Xofluza), available. From a treatment perspective we don't have a lot of choices for outpatient therapy for pediatric SARS-CoV-2 infections, and the monoclonal antibody combination bamlanivimab and etesivimab just authorized for use down to newborn ages but isn't likely to be effective against omicron. (Note that currently Children's National is not using age under 1 year as an independent risk factor for use of this combination.) NIH has a nice web site to check the latest on effects of different therapeutics for SARS-CoV2 variants, much based on in vitro data rather than solid efficacy studies because it's just too soon in the omicron wave for reliable analysis.

Setback and Hope for Pediatric COVID-19 Management

On December 17 we all learned via a press release that the Pfizer vaccine trial failed to reach the pre-established noninferiority margin for children 2 - 4 years of age, although that goal was reached in the 6 - 23 month old age group. As you know I am an investigator in that trial, at the time of this writing still waiting to hear specific plans for modification of the trial presumably to administer third doses to those children.

Also on December 17, CDC released reports of 2 studies of the "Test to Stay" (TTS) strategy for managing school attendance with positive covid cases, one from Los Angeles County, CA, and the other from Lake County, IL. A lot of us have been waiting for high-quality published data on this approach. The basic approach to TTS is described on the CDC web site, suffice to say ready access to testing must be available as well as compliance with masking and other prevention methods. We of course do not have data available for TTS efficacy in the omicron era but at the moment this seems to be a reasonable approach.

Bottom line for all of this, we are entering another worrisome time for COVID-19, no reason to panic but be careful and stay abreast of new developments. Please encourage everyone to get their influenza and COVID-19 vaccinations, including boosters for the latter.

A Slow Week

Bud WiedermannAugust 8, 2021Leave a comment

Well, not really slow in terms of the rise in COVID-19 cases, now with daily averages in the same range as last winter. But, I didn't see any groundbreaking studies released in the past week that you need to digest immediately. I did find a couple items that should interest you, however.

Vaccine Provides Better Protection Than Natural Immunity Against Reinfection

I was particularly interested in this MMWR report because one of my colleagues had contacted me about his family member a while back. The family member, who had a medical background, was using the fact that he had SARS-CoV-2 infection in the past as a reason to forego vaccination now. He felt he was already protected well enough, and my colleague was unable to convince him otherwise.

We certainly know that vaccination is less effective at preventing infection with the delta variant but still highly effective against developing severe disease. The recent MMWR report goes a step further, giving us pretty good evidence that immunization is better than immunity from natural infection at protecting from reinfection. If you know of anyone using prior infection as an argument against receiving vaccine, maybe you can steer them to this information.

Helping the Public Understand Variants

This is a tough order. The vast majority of us, yours truly included, are not practicing molecular virologists. The CDC just posted a video comparing variants to tree branches. Most of us learn better from graphical or pictorial displays of information rather than endless tables of numbers. See what you think of this 89 second video; recommend it to your patients, friends, and family members if you think it would help.

A Whole New Ballgame

Bud WiedermannAugust 1, 2021Leave a comment

More data became available this past week, and I think it is safe to say the delta variant is different enough that we will need to modify pandemic practices as the CDC has begun to do.

[Also, on a lighter note, I decided to investigate where the idiom in my title originated. As best I can tell, the first appearance in print was the March 13, 1971 issue of The New Yorker (page 30) in an unattributed posting in the "Talk of the Town" section commenting on what would happen if China entered the Vietnam War. The term appeared in quotation marks and I suspect that was a nod to the fact that the term was already in use.]

Delta Data

The CDC annoyed me early in the week when they came out with new recommendations for masking and other practices, referencing internal/unpublished data but not providing it. Subsequently the Washington Post released a draft slide set from the CDC that I read but was not going to comment on that because it was clearly a draft document. You can look at it but your time is better served by going to the CDC/IDSA COVID-19 Clinician Calls site where CDC's Dr. Tom Brooks provided an overview on Saturday July 31 (presentation not yet posted as of August 1).

Here's the bottom line on what's new and serious about the delta variant. A multisite outbreak on July 4 in Barnstable County, MA is showing us that not only is the delta variant highly contagious but also that vaccinated individuals had similar cycle threshold values to unvaccinated people. Cycle thresholds are sort of a biomarker for amount of virus in nasal secretions, though it is clearly not as reliable as, for example, viral load in blood in HIV patients. Cycle threshold also does not provide any exact translation into amount of viable intact virus present. Still, the concern is that even vaccinated individuals have significant amounts of replicating virus that they can pass on to other individuals and also are themselves a source of new variants. Another, non-peer reviewed, study suggests that the period of contagion with delta may be longer than with the original strain or earlier variants, though less so for vaccinated people. This could mean that quarantine periods after delta infection will need to be extended beyond our current guidelines. We need follow-up studies, but this early information is very sobering.

Note that we continue to see new, encouraging data that vaccination is still incredibly effective against infection (though slightly less so for delta variant) and for protection against hospitalizations and death. The mRNA vaccines are still working far better than anyone hoped to predict a year ago. (We don't yet have enough information about Janssen/Johnson & Johnson vaccine with delta, it hasn't been authorized as long so not as many people in the US have received it.)

Pandemic Communication

My whining about CDC being less than transparent and straightforward this week leads me to mention that CDC (and also WHO) has had a panoply of pandemic playbooks available well before the current pandemic, with a lot of updating following our 2009 influenza A pandemic (remember that?). I decided to browse the CDC's 2014 Crisis and Emergency Risk Communication Manual. At 462 pages it is not for the faint of heart, but it was interesting to reflect on communication with the current pandemic. In my nonexpert opinion, I would say that early in the pandemic it seems as if no one had even consulted this manual. Lately things are better, but the CDC needs to provide timely, clear updates and provide the supporting data at the same time so that the rest of us can make our own assessments. This is a tough job, no doubt, but I'm hoping they are learning quickly how best to manage public information in these very difficult times.

Of Vacations and Variants

Bud WiedermannJuly 11, 2021Leave a comment

Is Your Vacation Spot an Immunization Wasteland?

Overwhelming evidence suggests that immunization is a highly effective preventive tool for COVID-19 disease, With the delta variant now the leading strain circulating in the US, risk of infection is now higher than with previous strains and those immunized are somewhat less well protected. Thankfully, complete immunization does still protect well against serious disease; partial (single dose) immunization with either of the mRNA vaccines is not so great protection.

Much of the DC metropolitan area (the DMV) enjoys a high immunization rate, though some zip codes or wards have extremely low rates. But how about traveling beyond the DMV for summer vacation? I recently found a nice web site, US COVID-19 Vaccination Tracking, originating from Georgetown University. You can check out their interactive map to see if your dream vacation site is full of unvaccinated local residents, though only down to county-level detail. I'm not suggesting you change your vacation plans based on this, but at least you'll have some idea how much to worry when you go to the local grocery store.

Prior SARS-CoV-2 Infection Doesn't Give You a Pass on Immunization

This fact has been apparent for a few weeks now, though only from relatively difficult-to-decipher non-peer-reviewed sources. Now we have a peer-reviewed article in Nature with more easily accessible data. This dilemma is all thanks to the delta variant. If you happen to run across anyone declaring they don't need a vaccine because they already had COVID-19 infection, plus set them straight and encourage them to be immunized.

Myocarditis Concerns, and Delta Marches On 2

Bud WiedermannJune 27, 20212 Comments

Better Data on Risks of Myocarditis and Pericarditis from COVID-19 Vaccines

The ACIP/CDC held their meeting, postponed from June 18 due to the new federal Juneteenth holiday, on June 24. It was worth the wait, and fortunately I was able to attend the meeting online. You can see all of the presentation slides on their website, in particular I'd recommend the risk-benefit discussion by Drs. Wallace and Oliver. I had 2 major take-aways from the approximately 5-hour presentation.

First, as more time and cases have accumulated, the link between vaccines and myocarditis/pericarditis in adolescents and young adults (primarily male) seems much more convincing. The timing after the second dose, the striking age distribution, and the mostly mild clinical features strongly suggest a link even though the rates are very rare. It is worth mentioning this potential risk to people considering vaccination, though in these same demographic groups the risk of adverse sequelae from COVID-19 disease itself is much higher. Also note that this association was seen with both of the mRNA vaccines, Pfizer and Moderna, but I don't think we have enough information yet to know if this will occur with other COVID-19 vaccines. The mechanism of injury is still unknown and is the subject of much research.

Second, recognize that the only reason this was brought to light so quickly is that we have very massive and effective surveillance of adverse events with these vaccines. Please encourage all of your patients to sign up for V-safe when they are vaccinated, and everyone should report any suspected vaccine adverse events to the VAERS system.

Delta Variant is a Real Problem Everywhere

Evidence continues to mount that the SARS-CoV-2 delta variant is a major problem worldwide. It is unquestionably more easily transmissible than other variants by a long shot. Both mRNA vaccines seem to provide very good protection against severe disease caused by the delta variant, though preliminary data suggests that a single dose, rather than the recommended 2 doses, is not very protective. The jury is still out about whether delta causes more severe disease than other variants, but clearly this is the strain responsible for the vast majority of hospitalizations in developed countries, primarily impacting children and young adults who represent a disproportionate number of unvaccinated individuals. It likely will be the dominant strain in the US in a matter of weeks. Please encourage everyone to be vaccinated.

Somewhat more in the rumor category, a "delta-plus" variant has cropped up in the lay press. It is a strain that carries an additional mutation, K417N, that was known to be present in the beta variant and has been associated with poor response to treatment with monoclonal antibody preparations. We still need more information about this new sub-lineage strain to know its clinical significance.

Tag: delta variant