An Outbreak of Influenza A (H3N2) in a Well Immunized Nursing Home Population

Abstract

While antigenic drift of the circulating influenza virus was the major factor in the apparent vaccine failure, the observed poor staff immunization rate (10%) and absence of surveillance which precluded the use of amantadine chemoprophylaxis suggest that the use of these strategies may be of importance in controlling influenza outbreaks in nursing homes.

2012/13 influenza vaccine effectiveness against hospitalised influenza A(H1N1)pdm09, A(H3N2) and B: estimates from a European network of hospitals

“…[213] Also in contrast to the Cochrane findings, several studies have reported that vaccination can be up to 80% effective in preventing influenza-related mortality. [211,[214][215][216] Additionally, a study looking at the populationlevel impact of a vaccination program in Sao Paulo, Brazil detected a 26% reduction in age-specific influenza-attributable mortality following the introduction in 1998 of funding for annual mass vaccination campaigns for adults aged ≥65 years. [217] The effects of vaccination may vary between community-dwelling and institutionalized elderly populations.…”

Influenza vaccination in Dutch nursing homes: Is tacit consent morally justified?

“…High immunisation rates may result in herd immunity, involving increased protection for all residents, including the weakest amongst them (Coles et al, 1992;Drinka et al, 1997;Fox et al, 1971). Moreover, realising herd immunity may be the best way to prevent an influenza outbreak that will have devastating effects on daily life and care within the institution.…”

“…However, the level of immunisation among residents is not the only relevant factor for herd immunity. Immunisation of health care workers is also important, because of their possible role in introducing and spreading the virus among the nursing homes (Carman et al, 2000;Coles et al, 1992;Drinka et al, 1997;Fox et al, 1971;Nicholson, 2000;Potter et al, 1992). We have no data about the level of immunisation of health care workers in Dutch nursing homes, but, apparently, occupational immunisation is not given high priority: only 21.6% of the responding institutions in our survey explicitly request their personnel to get vaccination.…”

“…Evidently, it will be easier to produce high vaccination rates in nursing homes, only if the nursing home staff responsible for vaccination have numerous possibilities to approach target persons and their proxies; to convince them to accept vaccination; and ultimately to administer the vaccine on the basis of tacit consent. Moreover, nursing home physicians may have stronger reasons than family physicians to aim at high vaccination rates in their practice, because they may consider it desirable and possible to realise herd immunity (Coles et al, 1992;Drinka et al, 1997).…”

Cocoon Strategy of Vaccinations: Benefits and Limitations

“…A group of patients who are particularly at risk of hospital epidemics are residents of facilities, which render care and treatment services for patients with chronic illnesses. During the occurrence of an inluenza outbreak in a facility whose residents were at the age of above 65 years, the percentage of infected patients in an epidemic season was very high and it could reach even 60% [68]. The facts that inluenza vaccinations in the elderly are not as efective as vaccinations in a younger population (30-40% vs 70-90%), and that inluenza epidemics occurred in the populations of the residents of nursing homes, where inluenza immunization was very high and reached even 90%, prove that it is necessary to perform vaccinations in healthcare professionals in order to protect the patients [69,70].…”