Before the introduction of vaccination, Hib incidence was 30/100,000 among white, and 600/100,000 among indigenous people in Alaska. The incidence in the USA increased by 4 times between 1940 and 1970. The same happened in Scotland and Sweden.
Breastfeeding has a protective effect from Hib meningitis, and it lasts 5-10 years.
A short breastfeeding period (less than 13 weeks) increases the risk of Hib by 3.8 times. Children that are not usually healthy get infected 4.5 times more often.
Breast milk has an inhibitory effect on the attachment of bacteria to the mucous membrane of the nasopharynx.
The graph shows that a decrease in the number of breastfed babies is followed by an increase in the Hib incidence, and when the number of breastfed babied increased again – Hib incidence decreased.
Among children over 1 year of age, short breastfeeding period is associated with a 8-fold increase in the risk of Hib. Each additional week of breastfeeding decreases the risk of Hib by 5%. The protective effect of breastfeeding begins from 13 weeks of exclusive breastfeeding, and lasts for months and years.
Among children under the age of 6 months, exclusive breastfeeding is associated with a 90% decrease in the risk of Hib. Attending daycare is associated with a 2-6 fold increase in the risk. The larger are the groups at daycare, the higher is the risk.
Among children infected with Hib, those who were breastfed longer had higher levels of antibodies.
There were no increases in Hib incidence after the switch to acellular pertussis vaccine in Sweden and Finland. The authors believe that it is due to the fact that longer breastfeeding periods are common in these countries.
The authors measured antibodies level of 2,400 people in Sweden. 19% of people of the age of 20 and under did not have immunity against diphtheria. Among people over 40 years of age, only 15% had sufficient level of antibodies. Among the elderly, 81% of women and 56% of men did not have the immunity. On average, 70% of adult women and 50% of adult men had antibodies level below 0.01 IU/ml.
After 1978, it was discovered that 84% of pertussis patients had been vaccinated with three doses of the vaccine. Consequently, in 1979 Sweden stopped administering the vaccination. Only in 1996, when the acellular vaccine appeared, was vaccination reinstated.
In Sweden, there was a correlation between the incidence of SIDS and the nitrates level in water.
It is known that among people practicing anthroposophic lifestyle, the risk of allergic disease is much lower. Anthroposophic lifestyle is characterized by a preference for home births, a long breastfeeding period, a diet of organic products with an accent on vegetarian diet, limited use of antibiotics and antipyretics, and low level of vaccination, among other things.
This prospective study, which lasted 5 years, found that there were 2-3 times less cases of allergies among unvaccinated people. This correlation persisted even after the authors corrected the results for allergy risk factors (sex of the child, parental sensitization, mother’s education, mother’s smoking during pregnancy, number of siblings, life with animals on the farm, and exclusive breastfeeding till the age of 6 months). However, after the authors corrected for the anthroposophic lifestyle, it turned out that there was no longer a statistically significant difference between the vaccinated and unvaccinated. Despite the fact that the division into anthroposophic, partially anthroposophic and non-anthroposophic lifestyles was based on the subjective assessment of the parents, the authors conclude that there is no link between vaccination and allergies, and some other, unknown component of the anthroposophic lifestyle affects the reduced risk of allergies.
Between 1990 and 1995, the incidence of pneumococcal bacteremia among adults in Sweden rose 2.6 times. The same thing was observed in Norway.