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It was a busy week for infectious diseases, not in the sense of more outbreaks but rather more epidemiologic and vaccine data that point to better health for the future.

The big topic of the week was the Advisory Council on Immunization Practices regular February 2-day meeting. In retrospect, pediatric healthcare providers won't have any major new recommendations to work with; those are likely coming following the next meeting the end of June. I wasn't able to view as much of the meeting as I had hoped, patient care interfered a bit, but I did review all the presentations for those that I missed hearing live. Let's dive in.

ACIP

The Council discussed 9 different topics, but only 3 involved voting: COVID-19 vaccines (vote in favor of a spring vaccine for some high-risk people), Chikungunya vaccine (vote for use in some US adult travelers and in laboratory workers), Td vaccine availability for those with contraindications to receiving pertussis vaccine (discussion followed by a vote regarding the Vaccines for Children progam), influenza vaccines, polio vaccines, RSV vaccines for adults, meningococcal vaccines, pneumococcal vaccines, and the new Vaxelis combined product for diphtheria, tetanus, pertussis, polio, Hib, and hepatitis B. I'll expand on just a few of these topics. (Note all of the graphs/figures below are from the ACIP web site presentation slide link for the February meeting.)

RSV

We saw the most up-to-date representation of RSV epidemiology, showing that the epidemic curve for this year looks a lot like prepandemic years (see last presentation in RSV session).

A good part of the discussion centered on risk of Guillain-Barre syndrome following vaccine, compared to risks of GBS in the baseline population. Both are rare events, but I think at this point it is reasonable to conclude that GBS is a rare risk of RSV vaccination, though not enough to outweigh benefits for high risk populations.

A quick look at the benefits versus GBS risks for adults > 60 years of age (Melgar presentation from RSV session):

Note risks might vary with vaccine type - hard to know with rare events and large confidence intervals, plus both in the ballpark of background GBS numbers.

Influenza

This session was interesting for me to see a preliminary assessment of vaccine effectiveness for the 2023-2024 flu season. I'll just show you an overview of VE in the pediatric population; note that multiple methodologies are used to measure VE. (See slides from Frutos presentation in the influenza section.)

This is good VE for flu, certainly the CDC and WHO were on track for choosing the best combination of strains for this season. Look for the vote for next season's vaccine composition in June.

Meningococcal Vaccines

The focus of the discussion was how best to incorporate meningococcal B vaccine now that we have an approved combination vaccine containing this serogroup. Here are the main options discussed, from the 1st Schillie presentation:

The issues are complex, primarily due to 3 factors. First, meningococcal group B infections are extremely rare; traditional cost-effectiveness models show that meningococcal B vaccination in the US is by far the most expensive vaccine; very few cases are prevented due to the rarity of infection. Second, vaccination at age 11-12 risks significant waning of immunity by the age for peak meningococcal disease in adolescents; it might make sense to move the first dose to a later age. (The main argument against this is the confusion caused by eliminating the long-standing practice for vaccination at age 11-12, perhaps lowering overall vaccine acceptance.) Third, it is clear that not all meningococcal disease risk in adolescents is equal: college attendance is prime, but there are other behavioral risk factors (1st Schillie presentation):

The discussion was mainly to hear input from all stakeholders and then go back to the drawing board. Expect a vote on this at the June meeting - it will greatly impact your summer vaccine guidance for adolescents and young adults.

COVID Vacines

This section of the meetings seemed to garner the most publicity. Of course most of the results presented dealt with adults, given the relatively lower risk for bad outcomes in children plus low rates of vaccinations. Most helpful I thought were the discussions about covid VE in recent months looking at the fall monovalent vaccine.

These are great numbers. Also mentioned was the fact that waning of efficacy hasn't been seen yet, but that could just be a result of not having enough time to pass since the fall vaccine. Other good news is that in vitro studies suggest that the current monovalent vaccine is likely to protect against newer variants.

The official recommendations from CDC now state

Special situation for people ages 65 years and older: People ages 65 years and older should receive 1 additional dose of any updated (2023–2024 Formula) COVID-19 vaccine (i.e., Moderna, Novavax, Pfizer-BioNTech) at least 4 months following the previous dose of updated (2023–2024 Formula) COVID-19 vaccine. For initial vaccination with Novavax COVID-19 Vaccine, the 2-dose series should be completed before administration of the additional dose.

That "should" wording was the subject of much debate, finally choosing this wording more for simplicity of recommendations. The gnashing of teeth came about for a good reason - people in the lower end of this age population who do not have underlying risk factors will have less benefit from a spring vaccine because rates of bad outcomes in the post-pandemic period are lower.

Recommendations for younger people with moderate or severe immunocompromise have slightly different wording:

  • People ages 1264 years who are moderately or severely immunocompromised may receive 1 additional dose of any updated (2023–2024 Formula) COVID-19 vaccine (i.e., Moderna, Novavax, Pfizer-BioNTech) at least 2 months after the last dose of updated (2023–2024 Formula) COVID-19 vaccine indicated in Table 2. Further additional doses may be administered, informed by the clinical judgement of a healthcare provider and personal preference and circumstances. Any further additional doses should be administered at least 2 months after the last updated (2023–2024 Formula) COVID-19 vaccine dose.
  • People ages 65 years and older who are moderately or severely immunocompromised should receive 1 additional dose of any updated (2023–2024 Formula) COVID-19 vaccine (i.e., Moderna, Novavax, Pfizer-BioNTech) at least 2 months after the last dose of updated (2023–2024 Formula) vaccine indicated in Table 2. Further additional doses may be administered, informed by the clinical judgement of a healthcare provider and personal preference and circumstances. Any further additional doses should be administered at least 2 months after the last updated (2023–2024 Formula) COVID-19 vaccine dose.
  • For all age groups, the dosage for the additional doses is as follows: Moderna, 0.5 mL/50 ug; Novavax, 0.5 mL/5 ug rS protein and 50 ug Matrix-M adjuvant; Pfizer-BioNTech, 0.3 mL/30 ug.

As an aside and not receiving much media attention, a new report showed that vaccine mandates didn't help and probably hurt. States with vaccine mandates didn't have higher covid vaccination rates and actually had lower covid booster uptake and flu vaccination rates. Yikes!

Nipah Virus

Never heard of it, or hard-pressed to find facts at the tip of your tongue? Most providers in the US don't need to know much about this bat-borne virus, but if you have any patients planning a trip to Bangladesh you may want to advise them not to consume raw date palm sap (not on my list of delicacies so far) and to stay away from pigs.

NiV gets its name from the village of Sugai Nipah in Malaysia, site of a 1999 outbreak highlighted by cases of encephalitis in pig farmers. Outbreaks typically occur in Bangladesh and India. Now, the World Health Organization reports that 2 individuals, including a 3-year-old girl, have died from the infection after consuming raw date palm sap. The sap likely was contaminated with fruit bat droppings laced with NiV. In addition to signs and symptoms of encephalitis, typical findings are those of nonspecific febrile illness. Diagnosis is difficult until/unless encephalitis findings appear. It's a relatively uncommon infection even in Bangladesh, but mortality is high.

Good Attitudes

It's a sign of our times that I was pleasantly surprised to see a vaccine attitude survey with good news. Investigators from RAND corporation, University of Iowa, and CDC performed an online survey of 1351 parents to assess their willingness to have their children 5-18 years of age receive a vaccine to prevent Lyme disease. About two-thirds of parents definitely or probably would vaccinate their children. The boldface numbers below show statistically significant predictors of willingness to have their children receive Lyme vaccine, with willingness of the parent to receive the vaccine the strongest predictor.

In case you were wondering, for the purposes of this survey the high incidence states were Connecticut, Delaware, Maine, Maryland, Massachusetts, Minnesota, New Hampshire, New Jersey, New York, Pennsylvania, Rhode Island, Vermont, Virginia, Washington D.C. (yes, I don't need to be reminded it's not a state), West Virginia, and Wisconsin. They also looked at states characterized as "emerging" Lyme disease states (Iowa, Ohio, Illinois, Indiana, Michigan, North Carolina), but this group had a slightly lower rate of willingness than in high incidence states. Lyme vaccine trials in the pediatric and adult populations are ongoing, so don't be surprised if parents and children have this option in the next year or so.

Speaking of attitudes, take a look at AAP's new guidance for improving vaccine communication and uptake. It has an excellent literature review and describes various strategies that pediatric healthcare providers can use to improve vaccine acceptance. It is still true that different studies sometimes have reported different conclusions on how best to discuss vaccine hesitancy with parents, likely because it is very difficult to design studies that deal with such subjective issues in a uniform manner.

WRIS

Winter respiratory infection season is still chugging along, mostly due to influenza which is stubbornly persisting in scattered areas in the US. What a crazy patchwork!

New Covid Isolation Guidelines

Maybe this has overshadowed everything in the news. I've discussed this recently in the blog and was expecting the new guidelines to come in April, but CDC bumped it up by a month. It incorporates new information about covid epidemiology, hospitalization rates, and outcomes with balancing for impacts on the economy and on school and work attendance into a comprehensive guideline for all respiratory infections. So, no longer do we have a specific number of days after covid diagnosis to remain out of school or work. The document has multiple links and is pretty complicated. The CDC's press release is a good summary, however. Note that vaccination is still stressed heavily, though I expect it will be ignored by the same hardcore group of antivaxxers. Here's the quick blurb:

"When people get sick with a respiratory virus, the updated guidance recommends that they stay home and away from others. For people with COVID-19 and influenza, treatment is available and can lessen symptoms and lower the risk of severe illness. The recommendations suggest returning to normal activities when, for at least 24 hours, symptoms are improving overall, and if a fever was present, it has been gone without use of a fever-reducing medication."

I am very much in favor of these new recommendations. Circumstances have changed, and we have learned a lot from management of the pandemic these past few years. I just hope our vaccination rate will improve and that people with any respiratory symptoms at all will be aware that they can pose a significant risk to others who may have circumstances putting them at high risk for hospitalization or death from respiratory viruses. Also, please note this only applies to community settings; there are no changes for healthcare settings.

Squirrel Redux

If I were superstitious, I wouldn't mention the fact that my neighborhood squirrels still have not attacked my newly-positioned bird feeder. I was bemused by an article in the Local Living section of the Washington Post last Thursday, clearly written by a squirrel lover. Squirrels do have value, and I have no desire to wipe them off the face of the earth. I just don't want them eating all my bird seed.

A friend of mine in South Carolina with an array of bird feeders and birds also has come to terms with squirrels, albeit somewhat differently than my crazy solution. He just monitors things, and when the squirrels reach a point that he feels they become a significant barrier to maintaining bird happiness and seed access, he uses a humane trap to collect squirrels and then release them far from his neighborhood. I won't disclose where he releases them, but it sounded like a good place for squirrels and unlikely to bother too many people. I wonder if any of them found their way back to him.

A downy woodpecker said hello to me last week.

I was thumbing through my Farmer's Almanac this morning and noticed a mention of "Indian summer" for November 12. That's not a great term to use nowadays, so I'm opting for the European version called St. Martin's summer or day. I never bothered to see what these terms really meant, but I've learned it represents a period officially from November 11 to November 20 where we experience unseasonably warm weather. We've certainly had that recently, though November 11 and 12 in Maryland is back to cool fall weather.

Miscellaneous Vaccine News

I have no idea what a "miscellaneous" vaccine is, I was just desperate for something to title this section.

A new vaccine to prevent chikungunya virus infection was approved by the FDA this week for individuals 18 years and older at increased risk for infection with this mosquito-borne pathogen. It is a live virus vaccine. As with most arboviral illnesses these days, the vector range is expanding as our climate warms, and transmission has occurred within the US. Still, most infections in US residents are acquired via travel to more endemic areas such as Africa, southeast Asia, and Central and South America. The clinical illness is similar to dengue fever and mostly is a miserable but self-limited illness. However, elderly are at risk for complications, principally chronic joint disease. Newborns also are at risk for more severe disease, including death, and it is unknown whether the vaccine virus could be transmitted to the fetus. The package insert includes precautions for use in pregnant people. The main study supporting approval appeared a few months ago and looked primarily at side effects and antibody response, not actual vaccine efficacy. One big caveat, the manufacturer is required to conduct post-marketing studies to ensure that vaccine recipients do not develop a worse form of chikungunya after becoming infected; this is a possibility though not highly likely. For now, I'd consider this mostly as an option for older individuals at very high risk for infection. Most other US residents should wait for further information about the vaccine, but it's good we have this option available.

This past week also saw publication of new data from Singapore about benefits to newborns of covid vaccination of mothers during pregnancy. It was a cohort study, which is a study design slightly more prone to inaccuracies than are randomized controlled trials, but it did show about 40% efficacy in preventing infection in newborns when their mothers were vaccinated during pregnancy. Of interest, pre-pregnancy vaccination of mothers was not effective in preventing newborn infection. The study covered the period from January, 2022, through March 2023. This is yet another reason to encourage covid vaccination for pregnant people, along with pertussis and RSV vaccination. The benefits do extend to their children.

Unfortunately, we also have some disappointing vaccine news in the category of missed opportunities. First, 2 studies from the CDC demonstrated poor influenza vaccine uptake by healthcare providers. In the first report, flu vaccination rates for HCP in acute care hospitals fell from 88.6 - 90.7% in the years 2017-2020 down to 85.9% in 2020-2021 and 81.1% in 2021-2022. We all know that the pandemic made it difficult to access regular health care for many people, but these are workers in acute care hospitals who didn't have that excuse. The second study looked at a broader range of HCP during the 2022-2023 flu season and showed 81.0% flu vaccination rates in acute care hospital employees and a shocking (to me) 47.1% rate for nursing home employees. Up to date covid vaccination status rates were even more depressing: 17.2% and 22.8% in acute care hospitals and nursing homes, respectively. I can understand why some people may choose not to receive these vaccines, but HCP do have a responsibility to protect those for whom they provide care. (IMHO; I'll get off my soap box now.)

Also in the Debbie Downer category, CDC reported that vaccine exemptions for kindergarteners increased for the 2022-2023 school year. The rogues' gallery includes 10 states (Alaska, Arizona, Hawaii, Idaho, Michigan, Nevada, North Dakota, Oregon, Utah, and Wisconsin) having exemption rates above 5%. Idaho easily came out on "top" with a 12.1% exemption rate. The reasons for high exemption rates are complex, note that the list of states doesn't necessarily follow political lines. States that make it more difficult for parents to apply for non-medical, aka philosophical, exemptions have lower exemption rates overall. An oldie but goodie study also stressed that exemption rates vary within a state, and small hot spots with high exemption rates can fuel outbreaks of vaccine-preventable diseases.

Missed Opportunities to Prevent Congenital Syphilis

The CDC was very busy this past week! Another report looked at missed opportunities for prevention of congenital syphilis in 2022. Looking at the 3761 cases of congenital syphilis reported that year, almost 90% of birth parents received inadequate management. This included no or nontimely testing (36.8% of parents) and no or nondocumented (11.2%) or inadequate (39.7%) treatment. I'm hoping our public health infrastructure can be shored up to lower cases of congenital syphilis, now at a 30-year high.

Tripledemic Update

Rather than showing yet another RSV-NET graph, where data are somewhat delayed anyway, I thought I'd mention a bit more about that system. It is set up in 14 states covering about 8% of the US population. Here's what the distribution and data collection looks like:

I'm not sure why (Veteran's Day?) but FLUVIEW did not update this past week, so nothing new to report there. Wastewater covid levels reported by Biobot remain lowish.

No Hasty Pudding Again This Year

I'm starting to help plan a Thanksgiving menu for later this month, and I was reminded of another ill-named item, Indian pudding. It is similar to the British hasty pudding that uses wheat flour rather than cornmeal. I have a wonderful recipe, dated 1958, from the Durgin-Park Restaurant in Boston. Durgin-Park opened in 1742 and closed in 2019, and this dessert was an icon on their menu. The reasons I won't be having it again this year are multiple but include the fact that I'm the only one in my family who likes it and that it contains about 5000 calories per tablespoon (only slight exaggeration). I think I'll just change the name to Durgin-Park pudding for future reference.