Antigenic Drift in Influenza A Virus H3N2

By on 6:37 AM

On December 3, the Centers for Disease Control and Prevention (CDC) released a healthcare advisory relating to the circulation of influenza A (H3N2) virus in the nation. 

Between October 1 and November 22, an antigenic difference in the circulating influenza A virus compared to the strain found in the current vaccine was identified. Known as antigenic "drift," this will most likely result in a more severe flu season with the potential for higher morbidity and mortality.

The CDC is advising people who have not received the vaccine to get vaccinated as soon as possible because, despite that coverage for influenza A is diminished, the vaccine still provides protection against circulating influenza strains that have not undergone significant antigenic drift such as influenza A, H1N1 and influenza B viruses.

The CDC is stressing the importance for use of antiviral drugs which are most effective within the first 48 hours of the onset of symptoms, particularly for persons who are considered "high risk."

The 3-pronged approach to preventing outbreaks of influenza include vaccination, use of anti-viral medications particularly in high-risk individuals and basic infection prevention and control principals, including frequent handwashing, respiratory hygiene, cough etiquette (cover your cough) and staying home from work or school when ill.

Phenelle Segal, RN, CIC, FAPIC

Phenelle Segal, RN, CIC, FAPIC, is the founder and president of Infection Control Consulting Services LLC (ICCS). Phenelle has more than 30 years' experience providing customized comprehensive infection control and prevention services to healthcare facilities nationwide. Her services focus on assisting hospitals, ambulatory surgery centers, dental office and oral surgery practices, doctor's offices, nursing homes and other organizations with implementing and maintaining an infection control program that: complies with The Joint Commission, AAAHC, Centers for Medicaid and Medicare Services (CMS) and other regulatory agencies; respond to situations of noncompliance; and improve the processes for reducing risk.