This years’ seasonal flu shot carried out abysmally for lowering medical visits for influenza, based on CDC information.
For the 2021-2022 season, vaccine effectiveness in opposition to medical visits for acute respiratory infections (ARIs) associated to the predominant influenza pressure, A(H3N2), landed at a non-significant 16% (95% CI -16 to 39), reported Jessie Chung, MPH, of the CDC in Atlanta, and colleagues.
“These VE [vaccine effectiveness] estimates underscore the necessity for ongoing diagnostic testing for influenza, influenza antiviral remedy and prophylaxis when indicated, and on a regular basis preventive measures,” the authors wrote within the Morbidity and Mortality Weekly Report.
“Whereas flu seasons are at all times unpredictable, flu exercise up to now this season has been lower than in flu seasons earlier than the COVID-19 pandemic,” Chung informed MedPage At present.
However Chung famous that “there’s a rising physique of analysis suggesting vaccination can stop severe outcomes even when it doesn’t stop an infection,” and the CDC continues to advocate the vaccine throughout the flu season to scale back the chance of such outcomes, even when it reveals decrease effectiveness in opposition to a specific pressure.
For his or her interim report for the 2021-2022 season, the researchers examined information on 3,636 youngsters and adults searching for take care of ARIs enrolled within the U.S Influenza Vaccine Effectiveness Community from Oct. 4, 2021 to Feb. 12, 2022. The evaluation adjusted for research web site, age, month of sickness, and days from symptom onset to enrollment.
Individuals have been prospectively enrolled from seven websites — in California, Pennsylvania, Michigan, Tennessee, Texas, Wisconsin, and Washington — and included these 6 months of age and older searching for outpatient medical care or SARS-CoV-2 testing for his or her ARIs (together with fever, cough, or lack of style or scent) inside 10 days of their signs. Those that already have been handled with influenza antivirals akin to baloxavir (Xofluza) or oseltamivir (Tamiflu) have been excluded.
Total, 5% examined optimistic for the flu (influenza A) on RT-PCR. None examined optimistic for influenza B. Of 178 influenza A viruses that have been subtyped, 177 have been A(H3N2), whereas just one was the 2009 pandemic A(H1N1). Eleven examined optimistic for each influenza A and SARS-CoV-2 infections.
Among the many optimistic exams, 41% had obtained the 2021-2022 influenza vaccine, versus 50% of those that examined unfavorable. Documented flu vaccinations among the many members ranged from 31-64% throughout the seven websites, and principally relied on self-reporting.
“Influenza exercise is tough to foretell, and techniques to forestall influenza sickness stay essential to scale back pressure on well being care providers,” wrote Chung and coauthors. “Clinicians must be conscious that influenza exercise would possibly proceed or improve, and influenza must be thought of as a doable analysis in all sufferers with ARI.”
The authors acknowledged a number of limitations to the info. Due to inadequate enrollment, vaccine effectiveness couldn’t be stratified by age or vaccine kind. Healthcare searching for habits has additionally been reported to have modified throughout the pandemic, which can have influenced the outcomes.
Zaina Hamza is a employees author for MedPage At present, overlaying Gastroenterology and Infectious illness. She relies in Chicago.
Chung reported no conflicts of curiosity.Coauthors reported relationships with the Company for Well being Care Analysis and High quality, Campbell Alliance/Syneos Well being, FDA, Gilead, GlaxoSmithKline, Merck, Moderna, the NIH, Pfizer, Sanofi Pasteur, Seqirus, and the HHS/CDC.