January 25, 2018

Influenza Surveillance Update – Alicia Budd (CDC)

Alicia provided highlights of the influenza surveillance report from week 2, ending January 13, 2018. Influenza activity has continued to increase nationally.

The percentage of respiratory specimens testing positive for influenza in clinical laboratories was 25.6%, up slightly from the 24.7% positive reported in the previous week. The majority of specimens (~88%) tested at public health laboratories were influenza A, and ~12% were influenza B. Influenza A H3 (90%) continues to be the dominant strain reported, though smaller numbers of influenza A (H1) and influenza B also have been reported. Of the influenza B specimens on which lineage testing was performed, 91% were B Yamagata. Specimens characterized since May continue to be antigenically and genetically similar to the reference virus for this season’s vaccine. Of the several hundred viruses that have been tested, only 2 have shown any antiviral resistance. Both of these virus samples were H1N1, which is not the predominant strain this season.

Nationwide, influenza-like illness (ILI) activity was at 6.2%, up from the 5.8% reported in the prior week. This is the 8th consecutive week that we have been at or above baseline ILI levels. All 10 HHS regions are above their region-specific baselines. ILI information also is available on a state level, with activity summarized as high, moderate, low, or minimal. Last week, 32 states, New York City, and Puerto Rico reported high ILI activity, 9 states reported moderate ILI activity, 6 states and the District of Columbia reported low ILI activity, and 3 states reported minimal ILI activity.

Based on reports from the National Center for Health Statistics (NCHS) surveillance system available for the week ending December 30, 8.2% of deaths were due to pneumonia and influenza (P&I). This system has been above the epidemic threshold for two consecutive weeks.

Information from the Influenza Hospitalization Surveillance Network (FluSurv-NET) indicates an overall hospitalization rate of 31.5 per 100,000 population. The highest rate (136.5 per 100,000) was among adults aged >65 years, followed by adults aged 50–64 (33.2 per 100,000 population) and children aged 0–4 years (22.8 per 100,000 population).

Ten (10) influenza-associated pediatric deaths were reported during week 2. For the 2017–2018 season, the total number of reported pediatric deaths is 30. Of these, 5 were typed as H3N2, 8 were H1N1, 8 were influenza A that was not subtyped, and 9 were influenza B.

In terms of geographic spread of influenza within a state (characterized as regional, local, sporadic, or no activity) as reported by state and territorial epidemiologists, 49 states and Puerto Rico reported widespread activity, 0 states and Guam reported regional activity, 1 state (Hawaii) and the District of Columbia reported local activity, and 0 states and the U.S. Virgin Islands reported sporadic activity.

Alicia noted that this is the second week in which all states in the continental U.S. have reported widespread activity at the same time.

ACIP Recommendations for Use of Herpes Zoster Vaccines – Kathleen Dooling (CDC)

Dr. Dooling provided a presentation on the new recommendations for use of herpes zoster vaccines. The policy note on this topic was published in today’s MMWR. Following approval of the new recombinant zoster vaccine (RZV or Shingrix, GSK), ACIP issued this guidance to serve as a supplement to the existing zoster vaccine recommendations for the use of zoster vaccine live (ZVL or Zostavax, Merck).

In October 2017, ACIP recommended the following:

  1. RZV is recommended for the prevention of herpes zoster and related complications for immunocompetent adults aged >50 years.
  2. RZV is recommended for the prevention of herpes zoster and related complications for immunocompetent adults who previously received zoster vaccine live (ZVL).
  3. RZV is preferred over ZVL for the prevention of herpes zoster and related complications.

Dr. Dooling provided background on herpes zoster disease clinical manifestations and epidemiology. She noted that ~90% of herpes zoster infections are associated with pain. Treatment with antivirals can reduce the duration of the rash and pain. Pain continuing for at least 90 days following resolution of the rash is defined as post herpetic neuralgia (PHN). No effective treatment is available for PHN, and some treatments can have side effects, particularly in the elderly.

Approximately 1 million cases of herpes zoster (HZ) occur in the U.S. annually. The incidence of disease and PHN increase with age.

ZVL has been licensed in the U.S. since 2006, with ~33% of adults >60 reporting receipt of the vaccine. RZV is an adjuvanted recombinant protein subunit vaccine that was approved by the FDA on October 20, 2017.

Dr. Dooling reviewed the rationale for each of the recommendations outlined above. (NOTE: In addition to the following brief summary, see additional details in the links to the presentation and MMWR article provided above.)

RZV is recommended for immunocompetent adults aged >50 years due to its high efficacy against HZ and PHN. The vaccine maintained efficacy >85% for 4 years following vaccination in persons >70 years.

RZV is recommended for persons who previously received ZVL because RZV is more efficacious in all age categories. In addition, ZVL studies indicate significant waning of protection, which is not the case with RZV. Approximately 20 million people have been vaccinated with ZVL and are potentially eligible for RZV.

RZV and ZVL have not been studied in a head-to-head efficacy trial. However, RZV is preferred over ZVL because: (1) estimates of efficacy are significantly higher than ZVL estimates across all age groups, (2) RZV appears to wane at a slower rate than ZVL over the first 4 years, and (3) the expected cases of HZ and PHN averted are far greater with RZV compared to ZVL. Neither vaccine is associated with serious adverse events, but RZV is more reactogenic than ZVL. From an economic standpoint, RZV leads to more disease prevention and decreased overall costs.

Unlike ZVL, RZV is refrigerator stable, requires reconstitution prior to administration, and is administered IM. The vaccine schedule is 2 doses given at 0 and 2–6 months. It is recommended for adults with chronic medical conditions, adults taking low-dose immunosuppressive therapy, and those who are anticipating or have recovered from immunosuppression. It is given irrespective of prior receipt of varicella vaccine, ZVL, or herpes zoster episode. Screening for a history of varicella is not necessary.

For adults who previously received ZVL, no interference or safety problems were seen when RZV vaccination was administered >5 years after ZVL. HCP may consider an interval shorter than 5 years in patients >70 years; protection from ZVL is 38% for intervals >3 years. Although there were no studies of minimum intervals, expert opinion suggests a minimum interval of 8 weeks between the two types of zoster vaccine. Persons concerned about insurance coverage due to the timing between the two vaccines may wish to contact their insurance company. L.J asked Summit members to contact him with any reports of insurance denial due to both vaccines being given <5 years apart.

The only true contraindication to RZV is that it should not be administered to persons with a history of severe allergic reaction, such as anaphylaxis, to any component of the vaccine. Precautions include having a current herpes zoster infection, as well as pregnancy and breastfeeding.

Patients should be counseled about a higher level of reactogenicity (pain, myalgia, fatigue) with RZV, Reactions to the first dose do not strongly predict reactions to the second dose. Vaccine recipients should be encouraged to complete the series even if they experienced a grade 1–3 reaction to the first dose.

In response to a question, Dr. Dooling noted that an updated zoster VIS is not yet available. However, this is being actively worked on and should be available soon.

Announcements – L.J Tan (IAC)

2018 Summit In-Person Meeting

L.J reminded callers that the 2018 Summit in-person meeting will be held in conjunction with the National Immunization Conference (NIC) in Atlanta, Georgia. The NIC will be May 15–17, and the Summit will be May 17–18. Attendees are encouraged to participate in both events.

Information on registration and submission of poster abstracts for the Summit is now available online. (Persons needing to receive the password to access the site may contact L.J Tan.) The poster/networking session will be held on Thursday evening, May 17.

L.J requested that persons registering also use the Summit link to make hotel reservations through the Summit site. A block of rooms at a competitive rate is being held for Summit attendees.

2018 Immunization Excellence Awards

Summit members are encouraged to submit nominations for the 2018 Immunization Excellence Awards, which will be presented at the annual Summit meeting. Awards will be presented in the following categories:

  • Non-Healthcare Employer Campaign
  • Laura Scott NAIIS Immunization Excellence Award for Outstanding Influenza Season Activities Campaign
  • “Immunization Neighborhood” Adult Immunization Champion
  • Corporate Campaign
  • Adult Immunization Publication Award

The deadline for submission of nominations is February 1, 2018.

Upcoming Survey of Influenza Vaccine and Antiviral Medication Availability

Due to reported spot shortages of influenza vaccine and antiviral medications, L.J announced that the Summit will be conducting a survey beginning on Monday to assess availability of these products. This short survey will be conducted through Survey Monkey.

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