A summary of presentations from the weekly Summit partner webinars
June 30, 2022 – The latest Summit summary
Flu Surveillance Update – Alicia Budd (CDC)
Alicia Budd, MPH, NCIRD, CDC gave an update on the 2021–2022 influenza season. (VIEW SLIDES)
This flu season, as of the week ending June 18, 99% of the viruses nationwide were influenza A (H3) viruses. There were two waves of flu activity this season which is not unusual, however, both waves of activity were caused by H3 viruses. In most other seasons, there are both influenza A and B virus waves.
Of further interest, H3 was the predominant virus throughout all age groups, which also is not typically the case. Flu activity was first seen in those age 5–24 years, which may have to do with the early season university flu outbreaks, however, everything leveled out among all age groups as the season progressed. The second wave did not have as dramatic of an age fluctuation, as flu activity in all ages leveled out. The second wave was not nearly as dramatic when comparing age groups.
When comparing this season’s H3 age distribution with that which was seen in recent H3 predominant seasons, previous H3 predominant seasons did not nearly have such large amounts of H3 virus circulation. In the prior seasons, typically individuals age 5–24 were about 25% H3 positive and individuals age 65 and older were about 33% positive. This is a very different age breakdown than what we saw this year. This may have to do in part with the fact that COVID-19 virus testing, and therefore flu testing procedures, were different this season than in past seasons.
Of all the H3 viruses tested, 99.7% belong to the 3C.2a1b.2a.2 clade, and most were not antigenically similar to the vaccine reference virus. Some of the rarely seen influenza B (Victoria) viruses that were both antigenically and genetically characterized, were found to be similar to the vaccine reference viruses. In terms of antiviral susceptibility testing, more than 1,600 viruses were tested and there has been one H1 and one H3 virus with reduced antiviral susceptibility to Baloxivir and to neuraminidase inhibitors.
There has been a total of four novel H3 viruses identified this season. Often, novel viruses are variant viruses or flu viruses that are normally seen in pigs that are found to infect a person. This year, the latter was the case for three of the four novel viruses. The variant virus came from the individual who had avian influenza A(H5N1).
Currently, activity is still declining and in most of the age groups activity is stable and hovering at low levels. Long-term care facilities are continuing to see a decline and influenza-associated hospitalizations are low this year when compared to prior pre-COVID-19 seasons. This season has lasted much longer than prior seasons. Due to the longevity of this season, FluServ-NET decided to extend its surveillance season this year.
There have now been 30 pediatric deaths reported this season. Compared to prior seasons (except for last season), there have been fewer deaths among all age groups. NCHS mortality data shows that the percentage of deaths due to pneumonia, influenza, and COVID-19 (PIC) is driven almost exclusively by COVID-19.
CDC estimates that from October 1, 2021, to June 11, 2022, there have been:
- 8–13 million flu illnesses (normal range 9–41 million)
- 7–6.1 million flu-related medical visits
- 82–170 thousand flu-related hospitalizations (normal range 140–710 thousand)
- 5–14 thousand flu-related deaths (normal range 12–52 thousand)
Looking at the national numbers for peak flu week from week 50 (middle of December) of 2021 to week 17 (end of April) of 2022, it is clear that the first wave of flu activity came in early December and the second wave came in April. The most common month for peak flu activity is February, so both waves are outside of what would be expected in terms of timing.
When looking at regional activity extended to the end of May, the first peak of activity in December can be seen at around the same time regardless of location. The second peak occurred in different areas of the country at different times. The central part of the country saw a second peak around weeks 10–12 in 2022. Other parts of the country such as the southeast, pacific northwest, and west coast were seeing peak activity into May.
The activity came later than usual this year, but overall activity was low compared to what was seen during pre-COVID-19 seasons. It was speculated that low activity was due to low testing rates, however, there have been much higher testing rates in clinical laboratories than any previous season.
What is being seen in the U.S. is not unique. Globally, the 2021–22 season had less flu virus circulation than pre-COVID-19 seasons, however, the 2021-22 season has seen the most flu virus circulation since COVID-19 began. The timing of activity has not been usual in many counties, similar to the U.S.
Flu virus variants may surface this summer and there may be an early start to the 2022–23 season.
Do you have any thoughts on the current resurgence in the southern hemisphere?
This is the time when the southern hemisphere would be typically seeing flu activity. Australia started to see an increase earlier than usual, but not completely off-season for the southern hemisphere since it’s their winter now. They typically have low vaccination rates and low vaccination coupled with years of not really seeing the flu, therefore it took off quickly there. We don’t have any specific data as to why Argentina’s flu timing is off. This could be in part due to when they started to relax COVID-19 mitigation measures, giving flu a foothold.
Do you know why they are seeing this predominately in the youngest age groups?
Australia is seeing mostly H3s and some H1s, which are predominant in younger people, but that’s not unexpected.
Is there any information on Australia’s coverage rates?
I know historically the flu vaccine coverage is low in Australia. They have been expanding the free flu vaccines that they offer to younger age groups due to this season’s activity.
What are the theories about unusual patterns in timing for different respiratory viruses?
Nationally, RSV has been increasing for the last several weeks, which is similar to what it did last year but not a pre-COVID-19 normal pattern. In this new COVID-19 world, all respiratory viruses are fighting for position. No one knows what’s going on entirely, but it is seen in other countries, as well.
Is this unusual RSV pattern in all age groups or just children?
I don’t have a lot of visibility into this. The clinical lab system we use doesn’t have a lot of age data. When we do look by age, it’s predominately the younger pediatric age group.
ACIP Update – Andrew Kroger (CDC)
Andrew Kroger, MD, MPH, Medical Officer, Communication and Education Branch, Immunization Services Division, CDC, gave a presentation on the adult influenza update of ACIP from June 22–23, 2022. (VIEW SLIDES)
Age 65 and older
ACIP voted for the preferential use of higher dose or adjuvanted flu vaccines. That includes vaccines:
- Higher Dose: high-dose influenza vaccine (Fluzone High-Dose)
- Higher Dose Recombinant Influenza Vaccine (Flublok)
- Adjuvanted: adjuvanted influenza vaccine (Fluad)
The vote was based on the Evidence to Recommendations Process. ACIP determined that the higher dose or adjuvanted flu vaccines are preferred but that there is no preference between the three vaccines. If one of the recommended three vaccines is not available, then another age-appropriate vaccine may be used.
ACIP also voted on the policy statement which discussed the new strains for the upcoming season. The strains include:
Egg-based influenza vaccines:
- A/Darwin/9/2021 (H3N2)-like (New strain)
- A/Victoria/2570/2019 (H1N1) pdm09-like virus (Same strain as last year)
- B/Phuket/3073/2013 (Yamagata lineage)-like virus (Same strain as last year)
- B/Austria/1359417/2021 (Victoria lineage)-like virus (New strain)
Cell-culture and recombinant:
- A/Darwin/6/2021 (H3N2)-like (New strain, different from the egg-based vaccine)
- A/Wisconsin/588/2019 (H1N1) pdm09-like – (Same as last year, different from the egg-based vaccine)
- B/Phuket/3073/2013 (Yamagata lineage)-like – (Same as last year, same as egg-based vaccine)
- B/Austria/1359417/2021 (Victoria lineage)-like (New strain, same as egg-based vaccine)
New formulation: ccIIV (Flucelvax) was also given a new age approval. It’s now approved for individuals age 6 months and older.
MMR Vaccine (Priorix)
ACIP voted to recommend GlaxoSmithKline’s Priorix according to currently recommended schedules and off-label uses as an option to prevent measles, mumps, and rubella, an alternative to MMRII (Merck). There is no preference for one vaccine over the other; it’s just another vaccine option. This vote was also based on the Evidence to Recommendations Process.
Adult MMR recommendations:
- MMR is recommended for all adults who lack evidence of immunity to measles, mumps, or rubella. Evidence of immunity includes:
- Born before 1957 (healthcare providers excluded)
- Documented lab evidence of immunity
- Age-appropriate evidence of vaccination (varies by age and virus)
If an adult lacks evidence that they are immune, they are recommended:
- Two doses if:
- Healthcare provider (even born before 1957)
- Post-secondary school students
- International travelers
Exceptions to the two-dose recommendations above for people who are recommended to have two doses:
- A positive serology or laboratory evidence for both measles AND mumps (or other single-component immunity evidence for BOTH), but negative for rubella (susceptible to rubella) then you only need one dose
- Completing a two-dose series with one dose administered previously (exception: vaccination prior to one year of age does NOT count toward two-dose recommendation)
Most other adults will need one dose.
- Vaccination at age 6–11 months
- Three doses in a mumps outbreak
Avoid conception one month after administration of MMRII or Priorix.
ACIP’s influenza recommendations should be out in August.
What is the availability of Priorix for the VFC providers and others?
The vaccine only recently became licensed and posted on FDA’s licensure page. I’m not sure right now.
The 2022 Influenza Vaccine meeting, What’s Up with Flu in ’22! Surveillance, Vaccines, Policy, and Communications Last Year and Next, will be held virtually on May 19, 2022, from 2:00–4:45 p.m. (ET). Pre-meeting registration is required by 5:00 p.m. (PT)/8:00 p.m. (ET) on May 18, 2022, to attend. For more information and to register, visit: https://www.izsummitpartners.org/2022-naiis/.
The Summit is soliciting nominations for awardees for the 2022 NAIIS Immunization Excellence Awards. For the past two years, immunization stakeholders have gone above and beyond to serve the public health and healthcare needs of individuals and communities, and The Summit wants to recognize our heroes. The 2022 awards recognize individuals and organizations that have made extraordinary contributions towards improving vaccination access and delivery, health equity, and vaccine confidence within their communities during 2021–2022. The awards focus on individuals and organizations that exemplify the meaning of the “immunization neighborhood” (collaboration, coordination, and communication among immunization stakeholders dedicated to meeting the immunization needs of the patient and protecting the community from vaccine-preventable diseases). The NAIIS Immunization Excellence Awards recognize contributions to influenza vaccination and adult vaccination. Unless an award is specifically focused on influenza, it is the intent of The Summit to recognize broader adult immunization activities. Of course, vaccination activities related to COVID-19 vaccination and/or other vaccinations during the COVID-19 pandemic can and should be highlighted in your nomination packet. A National Winner will be selected for each award category. Where appropriate, an Honorable Mention recipient will also be selected. The winners will receive their awards at the NAIIS in-person meeting (tentatively scheduled for November 2–3, 2022, in Atlanta, GA). The national winner in each category will be invited to give a brief talk about their programs at the NAIIS meeting. The deadline for nominations is July 25, 2022.