Pollen of Parietaria officinalis causes season-associated respiratory symptoms. In Southern Croatia (Yugoslavia) we found 65% patients with rhinitis and/or asthma to be allergic to this pollen. They showed positive cutaneous reactions and had specific IgE antibodies to the respective isolated allergen. The finding represents the first report on Parietaria officinalis-induced allergy on the east Adriatic coast.

The addition of a parapertussis component to diphtheria–tetanus–pertussis vaccine reduces the agglutinogenic potency of the pertussis component in mice. The loss is evident when the amount of the parapertussis component added is 25% of that of the pertussis component, while the influence of relatively lower amounts of parapertussis organisms is less striking.The parapertussis component in these vaccines, amounting to 2–25% of the pertussis component, does not affect the protective power of the pertussis component in mice.

Investigations carried out to ascertain the ability of various strains of Bordetella pertussis and B. parapertussis to produce agglutinins have shown that the agglutinin response is considerably greater with B. parapertussis.Children inoculated with a combined vaccine in which the parapertussis element contained B. parapertussis in only one-twelfth of the concentration of B. pertussis in the pertussis element showed agglutinins in their sera in titres well above 1:300 for both organisms. There were no cross-reactions and the serological responses were specific throughout. The vaccine used was the standard diphtheria-tetanus-pertussis (DTP) prophylactic to which had been added a vaccine prepared from recently isolated strains of B. parapertussis.Agglutinin titres of both whooping cough components with the combined vaccine were somewhat lower in mice than was the case when monovalent vaccines were used, but they were considered to be satisfactory.It is suggested that the agglutination production test in mice could be used for the assessment of protective power of B. parapertussis vaccines against infection.I wish to thank Dr Ikić, director of the Institute of Immunology, Zagreb, who enabled me to perform all these examinations, further to Dr B. Mravunac and Dr Z. Radanov for having carried out vaccination in children and for the clinical examination of post vaccination reactions.