Trials of aqueous killed influenza vaccine in Canada, 1968-69

The appearance of the pandemic A/Hong Kong/1/68 (H3N2) influenzavirus strain provided an opportunity for a clinical field trial of influenza vaccines in Canada during the winter of 1968-69. As by November 1968 there were reports of influenza B activity and as supplies of A2/HK/68 vaccines were limited, it was decided to make a series of strictly randomized double-blind trials comparing A2/HK/68 vaccines not only with B/Mass/66 vaccines but also with a bivalent vaccine that was already in production and contained B/Mass/66 and A2/Mtl/68, the latter a strain isolated in Canada during January 1968. In 4 trials, a total of 13 729 military personnel and 4 795 primary schoolchildren were vaccinated. Reported vaccine reactions were less than 0.1% with zonally-purified vaccines and 2.6% with the “standard” aqueous killed bivalent vaccine. Three children had serious reactions. Surveillance detected an outbreak of influenza in the first two trials on the military. The 3 vaccines containing A2 strains gave similar clinical protection conservatively estimated at 42-55% but probably about 80%. The effectiveness of the A2/Mtl/68 vaccine, which was in production before the Hong Kong variant had been isolated, was unexpected. In the absence of a vaccine specific to a new pandemic strain, it should not be assumed that a vaccine made from another recent strain could not be useful.     

Rickets: concerns over the worldwide increase

Rickets is a childhood disease that causes a softening of the bones, potentially leading to fractures and deformity. Eighty years ago it was thought to have largely been eradicated from the U.K. However a recent increase in cases of rickets, not just in Britain but around the world, has proven this isn't the case. Today the disease affects children from all types of socio-economic backgrounds, not just the poorer ones, and it is primarily caused by low levels of vitamin D and certain foods. In January 2011 the government's chief medical officer Dame Sally Davies recommended all children aged six months to five should be given vitamin D supplements, particularly during winter months when natural sunshine is limited. The irony is that the advice in recent years for children to wear a high factor sunscreen and remain covered up while playing outdoors are partly felt to be behind the reason for its re-emergence. Parents and health professionals alike were shocked when it was revealed that a school girl living on the Isle of Wight developed rickets precisely because of her mother's vigilance at following sun safety rules. NICE, in their latest report (Jan 2011) stated that: "Exposure to the sun has a number of benefits. For example, it increases people's sense of wellbeing, allows them to synthesise vitamin D and provides opportunities for physical activity". A tendency for children to stay indoors and watch TV or play on computer games, rather than play outside when the sun is shining, is arguably also another contributing factor.     

Fluoride In Rickets

Although the total fluoride taken up in bones is reduced under conditions of rickets, the ratio of fluoride to total bone ash is increased.     

尿羟脯氨酸与肌酐比值对佝偻病的诊断价值

检测佝偻病患儿与健康儿童的尿羟脯氨酸含量，结果表明：佝偻病患儿尿羟脯氨酸与肌酐比值（ＴＨＰ／Ｃｒ）明显高于健康儿童组。相关分析显示尿ＴＨＰ／Ｃｒ与血清２５羟基维生素Ｄ３（２５（ＯＨ）Ｄ３）呈负相关，与血清碱性磷酸酶（ＡＬＰ）呈正相关。提示：尿羟脯氨酸可作为佝偻病诊断指标，方法简单易行。