Infection Prevention Manual

Type A influenza causes moderate to severe illness in all age groups and infects humans and other animals. Type B influenza primarily affects children, and infects only humans. Type C influenza is rarely reported as a cause of human illness and has not been associated with any epidemics. Impact of Institutional Influenza Outbreaks ,QVWLWXWLRQDO LQIOXHQ]D RXWEUHDNV FDQ KDYH VHULRXV LPSOLFDWLRQV SDWLHQWV DUH DW ULVN RI FRQWUDFWLQJ LQIOXHQ]D VWDII VKRUWDJHV FDQ UHVXOW RU EH H[DFHUEDWHG DGPLVVLRQV KRPH YLVLWV PD\ EH FXUWDLOHG DQG LQFUHDVHG FRVWV PD\ EH LQFXUUHG 3XEOLVKHG VWXGLHV FOHDUO\ GHPRQVWUDWH WKHVH RXWFRPHV Effectiveness and Safety of Influenza Vaccine FDA regulates vaccines for use in the U.S.; FDA and CDC are responsible for evaluating their safety and effectiveness and monitoring conformity with statutory and regulatory standards for licensure and use in the U.S. Ensuring an adequate, safe, and effective supply of influenza vaccine each year is one of FDA’s and CDC’s highest priorities. Because of the changing influenza viruses and the need for many months between strain determination and vaccine administration, vaccines and circulating viruses do not always match. Studies have shown that influenza vaccines are 59–91% effective in preventing laboratory-confirmed influenza illness when closely matched to the circulating virus strains. (YHQ LQ LQIOXHQ]D VHDVRQV GXULQJ ZKLFK WKH YDFFLQH GRHV QRW H[DFWO\ PDWFK WKH FLUFXODWLQJ VWUDLQ VWXGLHV KDYH VKRZQ WKDW WKH YDFFLQH VWLOO PD\ KDYH SURWHFWLYH HIIHFWV )RU RXU SDWLHQWV Vaccination of individuals 65 years of age and older not living in nursing homes reduces the likelihood of hospitalization for influenza-related complications by 30–70% when the vaccine is well-matched In this age group, influenza vaccination also has been shown to reduce both the frequency of secondary complications and the risk for influenza-related hospitalizations and death for those with and without high-risk medical conditions, such as heart disease or diabetes. Some studies have suggested that the influenza vaccine can be up to 80% effective in preventing death from influenza for individuals 65 years of age and older living in nursing homes or other LTCFs. The most common side effects associated with the inactivated influenza vaccine, administered as an injection, include soreness, redness, tenderness, and swelling at the injection site. These reactions are transient, generally lasting one to two days. Local reactions are reported in 15–20% of vaccinated individuals. Fever, malaise, and allergic and neurologic reactions occur rarely. Contraindications to inactivated influenza vaccines are severe (life threatening) allergy to a prior dose of a seasonal influenza vaccine, and severe allergy to a component of the vaccine. Live attenuated influenza vaccine (LAIV), administered as a nasal spray, is recommended for healthy, nonpregnant people 2–49 years of age. The most common side effects reported include cough, runny nose, nasal congestion, sore throat, and chills. To reduce the theoretical risk for vaccine virus transmission, it is recommended that HCP who receive LAIV should avoid providing care for severely immunosuppressed patients requiring protected environments for 7 days after vaccination, and patients visitors who have received LAIV should avoid contact with these patients for 7 days after vaccination but should not be restricted from visiting less severely immunosuppressed patients .