RE: “Flu shot benefits, hazards up for debate” a letter by Jennifer Craig (Nelson Star) It is really disappointing that a nurse would be questioning the safety of influenza vaccines and, even more so, that in a commentary on the Health Care Worker Influenza Prevention Policy, she would resurrect the now thoroughly debunked notion that the preservative thimerosal, at the very low doses found in some influenza vaccines, is somehow toxic for children. The fear engendered by the claims that autism and thimerosal were linked, along with the now thoroughly discredited work by Andrew Wakefield, has been responsible for outbreaks and deaths from vaccine preventable diseases among children as a direct result of diminished vaccine uptake. The WHO’s Global Advisory Committee on Vaccine Safety has concluded that there is no evidence of toxicity in infants, children or adults exposed to thimerosal in vaccines. Further, the Institute of Medicine, Immunization Safety Review Committee has found no evidence for an association between thimerosal-containing vaccines and neurodevelopmental disorders, including autism. During the first six months of life, infants can be exposed to about seven times more mercury through breastfeeding than through exposure to the influenza vaccination (assuming two pediatric doses) with even the higher thimerosal-containing product (12.4 mcg per infant dose). Expressing this amount in ppb is a meaningless exercise in scare tactics. There are no adverse mercury-related outcomes associated with either practice, but there are considerable benefits from both in terms of disease prevention. Influenza vaccine is recommended for infants, toddlers and children aged 6-59 months by the Canadian Pediatric Society, the National Advisory Committee on Immunization and the US Advisory Committee on Immunization Practice. This is to protect the very young from the serious complications of influenza. In contrast to the lack of any credible evidence linking thimerosal in vaccines to adverse effects on infant’s health, infants and toddlers suffer disproportionately from influenza. In fact, children in this age group are hospitalized because of influenza at a rate similar to that of elderly persons, with an estimated 75 to 375 infants and toddlers hospitalized each year due to influenza in British Columbia. As far as other vaccine components are concerned, there is an old adage that “the dose makes the poison.” Even water, if consumed in sufficient volume can cause harm and even kill and there is really no responsible health authority that does not attest to the overall safety and incremental benefit of influenza vaccines. The influenza policy that Ms. Craig questions does not mandate influenza vaccination. Health care workers have a choice. If they choose not to be vaccinated, they will be required to wear a mask in patient care areas during influenza season. Ms. Craig cites studies that question the efficacy of seasonal influenza vaccines. The most recent review, authored by a Professor Osterholme at the University of Minnesota, estimates an average effectiveness of 59 per cent — with a range from 45 per cent to 70 per cent depending on the vaccine match with the circulating virus. This is admittedly lower than we would like to see, but the present vaccines remain our best defence (coupled with hand and respiratory hygiene) against influenza and should be used while we look for a better vaccine. The Cochrane review also cited by Ms. Craig as evidence of lack of benefit accruing to patients as a result of health care worker vaccination, was recently critiqued by independent experts from Europe, Canada, the UK and the US. Dr. Janet McElhaney, a Canadian researcher and scientist at the Advanced Medical Research Institute of Canada, summarized the findings by stating, “The Cochrane study reanalyzed provides ample evidence of the ability of influenza vaccines to reduce the risk of influenza infections and death and the risk of frailty in the elderly. This key finding is that influenza vaccination is of major benefit to society as influenza vaccination will not only avoid unnecessary deaths (90 per cent of which occur in the elderly), it will help to minimize the permanent loss of vitality that is all too often a consequence of serious influenza illness.” Transmission of influenza from health care workers to patients has been demonstrated and can result in significant morbidity and mortality in vulnerable patients. The provision of influenza vaccine to health care workers with patient contact is considered an essential component of the standard of care. As far as the ethical standards of medicine and nursing, the professional bodies of both disciplines in British Columbia have issued statements referring to health care workers ethical duty of care to patients and supporting the health care worker influenza protection policy. Dr. Perry Kendall