August 2021 – Pediatric Infection Connection

See You in September

Bud WiedermannAugust 29, 2021Leave a comment

This song (as covered by The Happenings in 1966) has always stuck with me. September is upon us and schools are opening across the country. This year, however, these openings bring a bit more fear and arguments than in past years.

Another Lesson on Mitigation in Schools

Many of you likely have heard about the outbreak in an elementary school classroom in California reported in an early release from the CDC on August 27. The setting was an unvaccinated teacher who otherwise was following all the rules and teaching in a classroom that was optimized for prevention of SARS-CoV-2 transmission. The teacher became symptomatic but kept working plus routinely took his/her mask off to read aloud to students in class. What happened next is well summarized in this diagram from the report.

Note that the desks are 6 feet apart, an air filter was at the front of the room, the door was kept open, and windows flanking 2 sides of the classroom were open. The distribution and timing of cases in the classroom strongly suggest the teacher was the source of infection at least at the start of the classroom spread.

Vaccination, masks, social distancing, and other mitigation strategies all are important to keeping our kids safe when school opens.

Weighing Vaccine Risk/Benefits for Younger Children

Michael Schwartz, a former CNH pediatric resident and 1 of only 3 people (my wife and 1 of my 3 sons are the others) that I know actually read this blog, asked a great question last week that I wanted to answer more prominently this week. The folks at CDC have been great about distilling risks and benefits of the COVID vaccines as various rare adverse events have come to light in adolescents and adults, but do we have equivalent data for younger children to weigh the risks/benefits if and when vaccines are authorized for younger age groups?

I'm pretty sure CDC has access to unpublished numbers that they are monitoring, but for us regular pediatric healthcare providers I think the best place for summaries of pediatric information is the AAP/Children's Hospital Association biweekly reports. At the last update on August 19, things of course aren't looking good. It will be interesting to see how this changes as more schools are back in session. Also, remember that these data summaries are only as good as the sources. For example, the state of Texas (my place of birth, I'm sorry to say) has quit reporting COVID-19 data as of July 22.

Another Week of Confusion 1

Bud WiedermannAugust 22, 20211 Comment

The COVID-19 pandemic is confusing at baseline, but now others who should know better are aggravating the situation. My post this week is a little verbose, I'll try to return to concision next week.

To Boost or Not to Boost, That is (Not) the Question

Most evidence points to a need for a booster vaccine dose for the mRNA vaccines, but the timing is far from clear. So, I was dismayed to see that the main message this week was that everyone (some more than others) needs a booster 8 months following completion of the 2-dose series. Buried in the pronouncements was the fact that FDA and ACIP will look closely at the data to make a judgment. It is absolutely appropriate to plan for the possibility that booster vaccine doses will be administered in September, but don't use the need for advanced distribution planning as a surrogate for an 8-month booster timing. Let FDA and ACIP do their jobs.

I say this after having gone over the evidence with my best fine-tooth comb. Three reports appeared as early releases August 18 in MMWR. All are well-designed and well-reported studies utilizing different databases and study designs. One looked at hospitalizations in New York state from early May to late July, another at duration of effectiveness of mRNA vaccines March through July throughout the country, and the third (and only CDC study) looked at vaccine effectiveness in US nursing home residents March through July. The most important take-home point from all 3 studies is that the mRNA vaccines are all still tremendously effective at preventing severe illness and death. (The Janssen/J&J vaccine hasn't been in use long enough to make any concrete conclusions about changes in efficacy.) There was a slight decline in effectiveness in some groups recently, but whether this is due to waning of vaccine immunity, the appearance of the delta variant, or both isn't possible to sort out yet.

What really has had the steam coming out of my ears lately is the discussion of Israeli data, as yet unpublished in a peer-reviewed journal. It seemed to me to be a clear error in statistical analysis and reporting, something I would use an example in my old EBM classes. Just this week I found support in the form of an online site that explains the problem far better than I could. It is an example of Simpson's Paradox (Edward Hugh Simpson, not Homer). Briefly stated, Simpson's Paradox is "a trend or result that is present when data is put into groups that reverses or disappears when the data is combined." More simply, if one is not careful to take into account confounding variables, you can end up with conclusions that are the exact opposite of the truth. In the case of the Israeli data, reanalyzing numbers available from the Israeli government data dashboard showed that it is likely that claims of waning vaccine efficacy are a byproduct of higher vaccination rates in the elderly, who have more underlying risk factors, compared to the highly unvaccinated group of teenagers and young adults. When you correct for the confounding, or hidden, variables, the vaccine efficacy looks great for all ages.

Please Don't Administer Vaccines Off-Label!

I received an email from the mother of a child enrolled in our COVID-19 vaccine trial at Children's National. He received his 2 injections (either vaccine or placebo) a couple months ago and is doing very well, but mother is concerned because he will start school soon and has very mild asthma. (She felt this was a risk factor for severe disease but plenty of studies show that this is not a risk.) She had a few great questions, but what concerned me most is that she had heard from others that some healthcare providers were planning to administer COVID-19 vaccines to children 9-11 years of age which of course is not an authorized age group. I don't know if this is true, but I do know this is one of the worst ideas I've heard, right up there with drinking bleach.

DO NOT make up your own vaccine schedules. How would you know what dose to give a 9 year old child? What if there is a severe adverse reaction? Remember also that you need to report all vaccine doses administered. If you want to get involved with giving COVID-19 vaccines to children under 12, join a clinical trial. 'Nuff said.

A 3rd Vaccine Dose, Plus a Non-COVID Item

Bud WiedermannAugust 15, 2021October 24, 2021Leave a comment

A notable week for new vaccine recommendations for immunocompromised individuals, but could be confusing for some. Also, a bit of new information about a medical mystery that's been brewing the past few months.

3rd Dose of COVID-19 Vaccine for Moderately to Severely Immunocompromised People

Both FDA and ACIP weighed in this week to recommend a 3rd dose of mRNA vaccine to a subset of immunocompromised people. (Not enough data at this time to make any judgment for those who received Janssen/Johnson&Johnson vaccine.) These individuals as a group tended not to respond with robust immunity after the standard 2-dose regimen, and now we have some new data suggesting a modest improvement after a 3rd dose. Note however that this is just a modest improvement, many individuals still may not be protected after the 3rd dose and all should continue to use masks, social distancing, and good judgment in avoiding crowds, etc., as if they were not immunized. It is tough to exactly spell out what moderate/severe immunocompromise is, but essentially all of these patients are being followed closely by whomever is prescribing their treatments and would be able to advise them on an individual basis. CDC provides excellent explanations.

Ever Seen a Case of Melioidosis?

I haven't, and I hope I don't. It's a serious infection caused by Burkholderia pseudomallei that normally is seen mostly in adults with underlying conditions residing in eastern Asia, northern Australia, and to a lesser extent in Africa, the Caribbean basin, and Central and South America. This past week the CDC reported the 4th case of melioidosis in the US this year not connected with any travel or other risk factors for the disease or to each other. These isolated cases have occurred in Texas, Kansas, Minnesota, and Georgia. Two of the 4 cases have occurred in children. Furthermore, genetic testing has shown all 4 isolates to be closely related so likely from a common source, as yet unidentified.

The clinical presentation often is nonspecific, with severe pneumonia and/or a typical septic shock presentation. Sometimes draining abscesses can develop. The organism is high risk to lab personnel and they should be warned if meliodosis is suspected. Also, many of the automated and high-tech laboratory identification machines can misidentify this organism; I suspect all the clinical labs in our area are aware of this since so many notifications have gone out, but if by chance you have a severely ill patient with a bacterial culture growing any Burkholderia species (especially B. cepacia or B. thailandensis) or Chromobacterium violaceum, Ochrobactrum anthropi, Acinetobacter spp., Aeromonas spp., and maybe even Pseudomonas spp., please check with the lab.

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.

Month: August 2021