• Flu activity is unusually low at this time.
• An annual flu vaccine is the best way to protect against flu and its potentially serious complications.
• There are also flu antiviral drugs that can be used to treat flu illness.
National Influenza Activity:
According to this week’s FluView report, seasonal influenza activity in the United States remains lower than usual for this time of year.
Below is a summary of the key influenza indicators for the week ending April 24, 2021:
Viral Surveillance - Clinical Lab: The percentage of respiratory specimens testing positive for influenza at clinical laboratories is 0.1% this week.
Viral Surveillance - Public Health Lab: The number of influenza positives reported by public health labs remains unusually low.
Virus Characterization: Influenza virus characterization information will be reported later this season.
Outpatient Illness: For the third week in a row, 1.1% of patient visits to a health care provider were for Influenza-like illness (ILI). Nationally, ILI remains below the national baseline of 2.6%. ILI surveillance may be impacted by the COVID-19 pandemic and should be interpreted with caution.
Outpatient Illness: ILINet Activity Map During week 16, all jurisdictions experienced minimal activity. ILI activity levels may be impacted by the COVID-19 pandemic and should be interpreted with caution.
Influenza-associated Hospitalizations: FluSurv-NET sites reported a current cumulative hospitalization rate of 0.8 per 100,000 population, which is about one-tenth the rate reported at this time during the low-severity 2011-12 season.
NCHS Mortality: 11.8% of deaths were attributed to pneumonia, influenza, or COVID 19 (PIC ). This is above the epidemic threshold of 6.7%. Currently, the majority of PIC deaths are due to COVID-19. (NCHS:National Center for Health Statistics)
Influenza-associated Pediatric Deaths: No influenza-associated pediatric deaths were reported to CDC this week. The total for the season is one.
Influenza Activity in Massachusetts
Figure 1 shows that for MMWR week 16, the percent of ILI visits visits is lower than the two previous seasons in the same week. For more information, see CDC’s influenza surveillance website at
ILI Activity in Massachusetts by Region
Figure 4 shows the relative intensity of reported ILI activity in Massachusetts by region. Although regions may not all experience the same intensity of ILI at similar times, infections due to influenza can be found throughout Massachusetts during flu season. Figure 4 shows that all regions of Massachusetts are reporting minimal ILI activity.
For more information about flu, go to our Weekly Flu Reports.
Questions and Resources
MDPH Influenza Vaccine Guidelines and Tools. This webpage contains information about influenza vaccine and links to guidance about planning flu and other mass immunization campaigns, standing orders, screening forms, consent forms, and MDPH-specific vaccine management guidance.
This website helps professionals work with their patients and emphasizes the importance of your role in protecting the public against influenza each season. Your recommendation to your patients that they receive the influenza vaccine is critical and more effective in increasing acceptance of vaccination than any other influencing factor.
CDC Make a Strong Flu Vaccine Recommendation
Vaccine Ordering and Locating Clinics
A free, online service where users can search for locations that offer immunizations.
Providers Wishing to Order Flu Vaccine for Private Purchase:
The national Influenza Vaccine Availability Tracking System (IVATS) assists providers wishing to privately purchase flu vaccine. IVATS identifies available doses of influenza vaccine by formulation and distributor/vendor throughout the season.
For questions about influenza please call the Massachusetts Department of Public Health Immunization Program at 617-983-6800 or your local board of health.
MDPH Resources for Fall Vaccination Clinics
For questions about state-supplied influenza vaccine, please call the Vaccine Unit at 617-983-6828.