A lot going on in the world of infectious diseases this past week, enough to challenge my ability to sort out and explain the key points. That's probably why my mind, and eyes, keep drifting to the window next to my desk. The neighborhood leaf pickup is coming any day now, and many leaves cover the ground. The number of fallen leaves is still far less than remain on the old maple tree just outside the window. Yes, it's too early to rake, I would just need to do it again in another week.
Here's my stab at summarizing recent ID events.
RSV and Nirsevimab Shortage
CDC issued a HAN (Health Alert Network) advisory statement on October 23 with a plan for prioritization of nirsevimab use in the face of limited supply.
I won't attempt to summarize everything here because the recommendations are detailed and depend highly on individual circumstances impacting nirsevimab access; please read the advisory. The 100 mg dose is the most severely restricted, and practitioners should not combine 2 50 mg doses to make up the difference because you are essentially depriving 2 younger/smaller children from access in order to treat 1 other child. Note that palivizumab (Synagis) is still available and is the go-to product for infants 8 - 19 months of age, the same as in previous RSV seasons.
At last week's Advisory Council on Immunization Practices (ACIP) meeting (see more below), the nirsevimab company representative completely avoided answering a request to provide details for the cause of the shortage, other than to invoke a supply versus demand problem. I'm hoping those details appear down the road so mistakes like this can be prevented in the future.
Remember COVID-19?
I hope nobody has forgotten, but never underestimate our short attention spans. Thankfully things are relatively calm compared to pandemic times.
I felt the lay press got things a bit wrong when reporting findings of a study by FDA and others regarding safety of monovalent covid vaccines given to children before early 2023 (i.e. NOT the current vaccines). Unfortunately the report has not been peer-reviewed, but it appears pretty sound from my brief reading. The risk of myocarditis/pericarditis in adolescent boys was pretty much the same as we've heard about all along. Also mentioned was seizure risk in younger children, and this part was over-hyped by some news agencies. The association merits further study, but currently is very uncertain: "...seizures/convulsions signals were detected following vaccination with BNT162b2 and mRNA-1273 in children aged 2-4/5 years. However, in a post-hoc sensitivity analysis, the seizures/convulsions signal was sensitive to background rates selection and was not observed when 2022 background rates were selected instead of 2020 rates." The exact numbers were 72 children with seizures, most fulfilling the case definition of febrile seizures, out of 429,119 doses administered to that age group. Thus, it is very close to the background rate of febrile seizures, without vaccination, in that population.
Tripledemic Status
Well, more like a weak monodemic now, with RSV still the only one of our RSV/Influenza/Covid triumvirate to appear in appreciable numbers in most places. RSV-NET shows some hospitalizations in young infants below, but note that hospitalizations are only the tip of the iceberg for infections.
FluView activity is similarly low in most locales.
Biobot wastewater tracking for covid remains low.
New Immunization Schedules for 2024
As mentioned above, the ACIP met October 25 and 26 to cover a variety of subjects and reveal proposed immunization schedules for 2024 which were approved. This approval is awaiting some tweaking and then final signoff by the CDC director. The new schedules will have many new options, which is both good and bad. It's always nice to have more choices, but at the same time those choices create new complexities that aren't easy to explain; CDC doesn't have a great track record for making recommendations understandable. Potential changes include vaccines for COVID-19, influenza, meningococcus, mpox, pneumococcus, polio, and RSV (monoclonal antibody and vaccine). Release is planned for January 2024, earlier than usual.
Pediatric healthcare providers should take note of proposed new mpox vaccine recommendations, now just applying to age 18 and older but likely to eventually include ages as young as 12 years once NIH trials are completed, perhaps as early as next year. Like most outbreaks/epidemics/pandemics, mpox has evolved from the 2022 epidemic into a 2023 endemic problem now at about 1-4 cases per week on average.
Because of this, and the fact that a highly effective and safe vaccine is available, the new guidelines likely will recommend immunization for those at high risk:
Gay, bisexual, and other men who have sex with men, transgender or nonbinary people who
in the past 6 months have had one of the following:
- A new diagnosis of ≥ 1 sexually transmitted disease
- More than one sex partner
- Sex at a commercial sex venue
- Sex in association with a large public event in a geographic area where mpox
transmission is occurring - Sexual partners of persons with the risks described in above
- Persons who anticipate experiencing any of the above
We will also see new recommendations for pneumococcal vaccine now that a 20-valent pneumococcal conjugate vaccine is approved. PCV13 will phase out and infant immunization will include just PCV15 or PCV20. The 23-valent pneumococcal vaccine also will phase out, except perhaps for a stockpile kept for use in immunologic diagnostic testing.
Covid vaccination will be a little easier for young children, with clarifications for which vaccines to use for children undergoing age transitions in the midst of vaccine cycle as well as greater allowance for interchangeability of vaccines (e.g. administering Pfizer vaccine when previous vaccine was Moderna) for children 6 months through 4 years of age:
COVID-19 vaccine doses from the same manufacturer should be administered whenever recommended. In the following circumstances, an age-appropriate COVID-19 vaccine from a different manufacturer may be administered:
- Same vaccine not available at the vaccination site at the time of the clinic visit
- Previous dose unknown
- Person would otherwise not receive a recommended vaccine dose
- Person starts but unable to complete a vaccination series with the same COVID-19 vaccine due to a contraindication
The changes for meningococcal vaccination are the most confusing. A pentavalent vaccine was approved recently by FDA for use as a 2-dose regimen for ages 10 through 25 years. The confounding factor for meningococcal vaccination is that the disease is relatively uncommon, particularly for serogroup B where we see only a handful of cases annually. Furthermore, vaccine immunity wanes fairly quickly following group B vaccination, and we are potentially faced with healthcare offices needing to stock 3 different meningococcal vaccines to cover all circumstances. Here are the current recommendations for meningococcal vaccination:
Here's a look at the serogroup distribution by age (June 2023 ACIP meeting, presentation 3 slide 9 for meningococcus):
How best to add in the pentavalent vaccine? Just using that vaccine alone isn't a good idea. Trying to incorporate immunization against group B into the current schedule that starts at age 11 is likely too early to be effective. ACIP has been struggling for several months to come up with a plan for meningococcal vaccination that takes into account the relative rarity of the disease as well as the need to provide a pragmatic plan that can be implemented in diverse healthcare settings. They focused on 3 policy questions that were debated by working groups over the past several months:
PICO 2 was deemed unfavorable for a variety of reasons. We are left with deciding how best to use the pentavalent vaccine for situations 1 and 3, knowing that stocking 3 different meningococcal vaccine products may not be feasible for many practice settings. I expect continued tweaking of the options before we see the final guidelines in January, but it appears that routine immunization will still be recommended at age 11-12 years with second dose at 16 years. Group B vaccination options will variously allow use of the monovalent or pentavalent products, but it may be that the pentavalent product will be recommended for a slightly different age range (16 - 23 years) than what was approved by FDA (10 - 25 years). Regardless, the Menactra vaccine (covering groups A, C, W, Y) will be withdrawn so at least some simplification there.
A concluding disclaimer to this section: all we have now from ACIP are proposed changes. They are not approved and very likely will undergo some changes before we see them in print. Please don't act on the above until we have the updated guidelines from CDC.
Staring Out the Window Again
You can perhaps understand my tendency to wander after reading the section above. The meningococcal vaccination options are almost endless, and I didn't necessarily agree with the way the discussions were going at the ACIP meeting.
The title of this posting is a lame riff on Shakespeare, and his Sonnet 73 mentions leaves prominently. However, it is primarily a poem about aging and I didn't necessarily want to be reminded of that! I found a more playful ode to autumn in a poem by James Whitcomb Riley; he has a children's hospital named after him although he was a very complex individual who suffered from alcoholism and wasn't exactly a model citizen. His poems often are written with a child-like voice and lend themselves well to reading aloud.
"But the air’s so appetizin’; and the landscape through the haze
Of a crisp and sunny morning of the airly autumn days
Is a pictur’ that no painter has the colorin’ to mock—
When the frost is on the punkin and the fodder’s in the shock."
