Search:

A summary of presentations from the weekly Summit partner webinars

December 12, 2024 – The latest Summit Summary

Vaccine Coverage Update – Carla Black, PhD Lead, Influenza and Adult Coverage Assessment Team, Surveillance and Epidemiology Brand, CDC

Carla Black, PhD, gave an update about influenza, COVID-19, and RSV vaccine coverage.

VIEW SLIDES

Influenza, COVID-19, and RSV Vaccination Coverage Update – Carla Black, PhD
Most of the data presented in this section came from the National Immunization Survey – Adult COVID Module and the NIS Flu Module for Children. The pregnancy coverage data came from the Vaccine Safety Datalink.

Influenza Vaccine Coverage
For adults, there was a slight increase in seasonal vaccine coverage in 2020-2021 compared with 2019-2020, but there has been a decrease since then. Although adults ages 65 and older have returned to a “pre-pandemic” baseline, the declines in coverage are mostly happening in the younger age groups, particularly in those 18 to 49 years of age.

  • For this season, as of the end of November, the vaccination rate for adults is about 39%, which is very similar to last season.
    • The percentage of people who already have been vaccinated against flu or said they will definitely get a flu vaccine is 50%, which is one percentage point less than those who said the same last year.
      • Those indications have proven to be fairly accurate in the past, so the expectation is that this year’s coverage rate will be just at or below the percentage (48%) vaccinated against flu at the end of last season.
    • Flu vaccine coverage is lower among people in rural areas; higher among Asian and White adults, and lower among Black and Hispanic adults; and much higher among insured adults than among non-insured adults.
  • IQVIA data, which is from medical claims in pharmacies and physician offices, show that about 3 million fewer influenza vaccine doses have been given this season than last season. Although the lag may be caused by claims data issues or influenza vaccinations occurring in other settings (e.g., occupational settings), it does underscore the likelihood that flu vaccination coverage will not be higher this year than last.

For children, despite an upswing in coverage pre-pandemic, there was a decrease in flu vaccination beginning between the 2019-2020 season and the 2020-2021 season, which has continued.

  • For this season, children who have been vaccinated against flu and those whose parents say they will definitely have their children vaccinated against flu are both lower compared with last season.
    • There are data from IQVIA indicating that coverage actually may be higher for children, but there may be discrepancies due to VFC versus non-VFC differences, or the data could reflect better capture of pharmacy claims than medical office claims.
    • For children, flu vaccine coverage is lower among children in rural communities; about the same for White and Black children, with both of those groups having lower rates than Hispanic and multiracial children.

COVID-19 Vaccine Coverage
Although coverage is still much lower than desired, COVID-19 vaccine coverage is higher this season than it was last season, at 20% versus 16%.

For adults this season, intent to get vaccinated against COVID-19 is lower and perhaps hesitancy is increased.

  • For adults over 65 years of age, this season, about 41% has already been vaccinated against COVID-19, whereas the end-of-season percentage vaccinated last season was 40%.
  • For adults, there is lower coverage for COVID-19 in rural populations and lower coverage for Black and Hispanic adults compared with White adults. There is also less hesitancy in Black and Hispanic adults, so more of those individuals are in the ‘moveable middle,’ i.e., those who may be open to moving to vaccination.

For children, this season has similar COVID-19 vaccine coverage (about 10%) compared with last season.

  • Demographically, coverage for children is low across the board.

RSV Vaccine Coverage
For adults this season, there is a new RSV vaccination recommendation. Last season RSV vaccination was presented under a shared clinical decision making recommendation. The vaccine coverage numbers have increased under the new recommendation.

  • As of the end of November 2024:
    • For those 75 and older, RSV vaccine coverage was about 43%, about 11 percentage points higher under the new recommendation
    • For those ages 60-74 with high risk, RSV vaccine coverage was about 32%, about 9 percentage points higher under the new recommendation

For infants this season, the coverage calculations reflect the age at which infants are recommended to receive RSV protection (either through maternal vaccination or nirsevimab) based on date of birth and start of the season.

  • As of November 2024, RSV protection coverage in infants is about 45% overall. For infants less than 8 months and recommended to be protected, about 38% had nirsevimab and 7% were protected by maternal vaccination. (Maternal vaccination is not low; these numbers reflect the ages of the infants and eligibility for the season, see below.)

Vaccine Coverage in Pregnant People

  • Influenza
    • For this season, about 34% of pregnant people have been vaccinated against influenza, a much lower percentage compared with the pre-pandemic 2019-2020 season.
  • COVID-19
    • For this season, vaccination against COVID-19 is a little bit higher than last season, but still very low overall among pregnant people.
  • RSV
    • For this season, of pregnant people in the window of eligibility for RSV vaccination about 33% have been vaccinated.

Note: All the data that was shared in this presentation can be found online at RespVaxView: https://www.cdc.gov/respvaxview/about/index.html.

QUESTIONS & ANSWERS

Q: Do you have a sense, with the surveys, what continues to drive these rates down? The loss of medical practice seems to be one factor. Are we at rock bottom, yet?
Carla Black (CDC): For children, we are working on a paper looking at reasons for parents reporting non-vaccination. And what has increased over the years, of course, people still say that they’re concerned about safety, but not being concerned about flu or not being concerned that you’ll get very sick from flu. That’s seems to be the reason that has been increasing over the years. That’s for kids. We speculated for adults that – I don’t know that we have data to show this – that fewer provider offices stocking vaccine is related. For pregnant women, I really can’t say. Actually, we always ask for reasons for non-vaccination but the reasons are always the same. They’re concerned about safety for the baby. There are now potentially – depending on timing of pregnancy – four vaccines that a woman could get while she is pregnant. I don’t know how much that’s a factor.
L.J Tan (Immunize): One of our sessions at the in-person Summit meeting in May 2025 is on maternal immunization, and we’re hoping to discuss exactly what you just said: this idea, for maternal vaccines, how do we make those vaccinations happen? That’s an important point. Do you have any information about the nirsevimab coverage versus the maternal immunization coverage? It sounds like 35% of infants were protected by one or the other and, of that 35%, 33% were protected by maternal immunization. Is that right?
Carla Black (CDC): No, it’s kind of hard to compare the two because the denominators are different. If you look at the infants that are eligible, that would be less than 8 months during the respiratory season, it’s infants born all the way back to April of 2024. So, for those infants, their mother would not have been eligible. So, in the data that I showed on the slide, only about 0.2% were protected by maternal vaccination, but that’s because they were all born before. And the more recent data, it’s 38% by nirsevimab and 7% by maternal. But, again, most of those infants wouldn’t be eligible for maternal. So that’s why, if we look at only the mothers who were eligible, that number is about 33% of them have got RSV, but that doesn’t account for how many of them might have been waiting for them to get their infants nirsevimab instead. It’s complicated, those numbers.
L.J Tan (Immunize): That’s going to be important information as we go into next season: what’s the best way to message to maternal providers and, then, to pediatricians. And who wants to take the lead in protecting the infant against RSV? Should it be at maternal immunization or should it be at the birthing hospital through nirsevimab?

Q: Does CDC have an estimate of the percentage of people with chronic diseases who have been hospitalized or died due to respiratory virus infections during the season? Chronic conditions, as we know…we do see a few articles in MMWR that have published reports from the cancer registries, but a nationwide report would be nice.
Carla Black (CDC): We do not monitor hospitalization data, just the vaccination data. I would defer to Katie or Ben on that question.
Ben Silk (CDC): I’ll be talking a little bit more during my presentation on some of the burden estimates that were newly released for COVID and RSV. And burden estimates for flu have been around for quite a while. That’s the “yes” part to the question; the “no” part is that they’re not specific to the population of people who have chronic diseases per se, at least not what we’re doing routinely.

BACK TO TOP

Seasonal Influenza Updates – Katie Reinhart, PhD, MPH, Influenza Division, CDC

Katie Reinhart, PhD, MPH, gave an update on seasonal influenza activity.

VIEW SLIDES

Influenza Update; 2024-2025 – Katie Reinhart, PhD, MPH
Seasonal influenza activity is continuing to increase but remains low nationally.

  • Outpatient respiratory illness is above baseline nationally, and increasing. Influenza A(H1N1) and A(H3N2) are co-circulating, with low B viruses.
    • Monitoring and testing for influenza A(H5N1) continue.
  • CDC recommends that everyone 6 months and older get an annual flu vaccine.
  • Prescription flu antivirals can treat flu illness and should be started as early as possible, especially in higher risk patients.

Outpatient Respiratory Illness
Looking at ILINet and national data reveals a steady trend upwards in outpatient visits for influenza-like illnesses (ILI) – fever with a cough or sore throat – this season.

  • The past week was the first week where visits for ILI rose above the national baseline, at 3.2% of patient visits for fever with a cough or sore throat.
    • Those in the lower age groups, 0 to 4 years and 5 to 24 years, have the highest percentage of these visits, and have also been trending upwards.
  • Geographically, during week 48 of this year, there were 4 jurisdictions that had either high or very high influenza-like illness activity and 9 jurisdictions with moderate activity levels.

Virologic Surveillance

  • At clinical labs, the percentage of specimens that were positive for flu has been trending upwards and was at 3.5% during week 48 of this year.
  • At public health labs, the percentage of positive specimens by type and subtype were about 36% influenza A (H1N1) and 62% influenza A (H3N2) during week 48 of this year.
    • Very few B viruses are being seen currently.

Emergency Department Visits and Hospitalizations

  • Emergency Department visits are beginning to trend upwards at week 48 of this year.
    • The most recent increases were among those ages 0 to 4 years and 5 to 17 years.
  • Hospitalization data through FluSurv-NET does not show much of an increase at week 48 of this year.
    • The hospitalization rate was estimated to be at 0.4 per 100,000 population. The highest rate of hospitalizations is among adults ages 65 and older, followed by adults ages 50 to 64 years.

Mortality
At this early point in the season, there are no increases in mortality.

  • About 1% of deaths that occurred were due to influenza at week 48 of this year, which is stable compared with the previous week and since last season.
  • There have been 2 pediatric deaths reported thus far this season, both associated with influenza A.

QUESTIONS & ANSWERS

Q: Is it still too early to decide whether H1 or H3 is going to become the predominant influenza strain, or if there will be co-dominance?
Katie Reinhart (CDC): Yes, I would say it’s still too early. Right now, it’s fairly skewed, but anything could happen. We still have really low circulating rates and it could be a season with two peaks, as well. We just don’t know, yet.

Q: Any data on vaccine match right now, in terms of circulating strains and vaccine strains?
Katie Reinhart (CDC): I just started to look at that before jumping on this call and it looks like we do have the antigenic and genetic characterization data that we’re putting out in FluView. That includes data on viruses going back to about May and, as you know, we’re not seeing 100% match, so not like what we were seeing last season where we had quite a bit of match, but I wouldn’t say that it’s awful, either. I’ll try to have a more specific update on that next time we meet.

BACK TO TOP

Coronavirus and Other Respiratory Viruses – Benjamin J. Silk, PhD, MPH, Coronavirus and Other Respiratory Viruses Division, National Center for Immunization and Respiratory Diseases, CDC, and Monica Patton, MD, Epidemic Intelligence Officer, CDC

Ben Silk, PhD, MPH, and Monica Patton, MD, gave an update on in-season COVID-19 and RSV surveillance.

In-Season Updates on COVID-19 and RSV – Benjamin J. Silk, PhD, MPH and Monica Patton, MD

National Respiratory and Enteric Virus Surveillance System (NREVSS) Data
NREVSS is a passive, laboratory-based system used to monitor real-time virus circulation and trends in seasonality for respiratory and enteric viruses. The majority of the data from NREVSS comes from PCR detections.

  • SARS-COV-2
    • PCR test percent positivity for SARS-COV-2, for May 21, 2022 through December 6, 2024, shows a continuing trend of periodicity with bi-modal activity waves happening 2x/year in summer and winter.
      • There was a large increase in percent-positivity in summer 2024, more than past summers and the winter of 2023-2024.
      • There seems to be a clear signal for an uptick starting now; the last two winters the uptick started 4 weeks earlier, indicating that the peak this winter may be later in January.
      • Despite signs of a national uptick, looking by region in the last week, percent positivity has been stable or only showed small increases.
    • Comparing years from July 2020 through December 2024 reveals the higher summer peak of 2024 and a lower incidence of positive PCR test results in fall 2024. This may indicate the potential for a later and less intense COVID winter.
  • RSV
    • Regional trends in RSV are important: it starts in the southeast each year and works its way north and west.
      • This season, the regions with highest percent positivity have been Region 6 (Texas and surrounding areas) and Region 3 (Northeast), although at this point, all regions are showing increases in RSV activity.
      • This season, RSV has returned to the typical seasonality and levels seen before the COVID-19-pandemic .

National Syndromic Surveillance Program (NSSP) Data
NSSP provides near-real-time statistics for influenza-like illness, COVID-19-like illness, and inpatient status.

  • Discharge Diagnoses specific to COVID, RSV, and Influenza in Recent Weeks
    • For COVID, the percentage of visits in all ages is very low.
    • For RSV, the percentage of visits are highest for infants under 1 year, and also high in those 65 and older.
    • For influenza, the percentage of visits is increasing in many age groups.

Levels of Acute Respiratory Illness (ARI) on CDC’s Respiratory Illness Data Channel
The data in the ARI index help demonstrate for the public that there are respiratory illnesses other than COVID, flu, and RSV. The levels are state-specific and calibrated to low levels off-season for each of the respiratory viruses.

  • For the past week, there is considerable variation between states for discharge diagnoses.

Respiratory Virus Hospitalization Surveillance Network (RESP-NET) Data
RESP-NET is an active, population-based surveillance network for RSV, COVID-19, and influenza before or during hospitalization in acute care hospitals.

  • Weekly rates of COVID-19 and RSV
    • COVID-19-associated hospitalization rates have been trending down for some time.
    • RSV-associated hospitalization rates are experiencing an uptick for young children.

National SARS-COV-2 Genomic Surveillance System
For genomic surveillance of SARS-COV-2 variants and nowcasting, there are multiple pathways to acquire specimens or sequence data used to provide prevalence estimates of variants every 2 weeks:

    • The National SARS-COV-2 Strain Surveillance (NS3) submission of specimens from public health labs.
    • Purchased sequencing data from commercials laboratories
    • Sequences from public repositories tagged for surveillance
  • As of December 3, 2024, the most common variant is Omicron lineage XEC; other common variants are KP.3, MC.1, and LF.7.

Burden Pyramid for COVID-19 and RSV Burden Estimation
Using data on hospitalizations from RespNet, combined with census data and using multipliers, burden estimates have, for the first time, allowed for preliminary, in-season estimates of the burden of COVID-19 and RSV. These burden estimates can be a useful tool in advocating for the uptake of vaccines in-season.

  • For COVID-19, CDC estimates that, from October 1, 2024 through November 30, 2024, there have been:
    • 2.2 million – 4.0 million illnesses
    • 540,000 – 940,000 outpatient visits
    • 64,000 – 110,000 hospitalizations
    • 7,500 – 13,000 deaths
  • For RSV, CDC estimates that, from October 1, 2024 through November 30, 2024, there have been:
    • 330,000 – 700,000 outpatient visits
    • 17,000 – 34,000 hospitalizations
    • 690 – 1,700 deaths

There were no questions for this session.

BACK TO TOP

Announcements
  • The in-person Summit meeting will be May 13 – 15, 2025, and registration will open in early January 2025.

BACK TO TOP

Search: