4',6-Dichloroflavan, a potent inhibitor of rhinovirus replication in vitro, was tested in a double-blind placebo controlled volunteer trial for its protective effect against experimental rhinovirus infection. Dichloroflavan was given orally (1 mg/kg, 3 times per day) for 3 doses before, and 13 doses after intranasal challenge with rhinovirus type 9, a type known to be highly sensitive in tissue culture. A total of 63 volunteers were included in the analysis for efficacy. Dichloroflavan did not produce any consistent or significant reduction in quantitative clinical or laboratory evidence of infection, and there was no apparent negative correlation of such data with drug concentrations in plasma. It is concluded that administration of dichloroflavan in the oral formulation tested is not of value in the treatment of human rhinovirus infection.

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Purified lymphoblastoid interferon (HuIFN-alpha) or placebo was self-administered intranasally by volunteers using a spray device three times daily for four and one-third days beginning one day before virus challenge. Each subject received a total dose of 35.1 Mu of interferon (IFN) administered in 13 equal doses of 2.7 Mu. Doses were administered in a volume of 0.2 ml (0.1 ml to each nostril). The first group received human rhinoviruses types 9 and 14. There were no significant colds in 19 volunteers receiving IFN and 7 in 23 volunteers receiving placebo (p less than 0.05). Serological responses and/or recovery of challenge virus were obtained in 14 (74%) recipients of IFN and in all 23 recipients of placebo (p less than 0.05). Mean daily and total clinical scores and mean daily and total nasal secretion weights were significantly greater in those receiving placebo than in those given IFN. The second group received influenza virus A/Eng/40/83. There were 4 significant illnesses in 13 volunteers receiving IFN and 10 in 17 volunteers receiving placebo (p greater than 0.05). Serological responses and/or recovery of challenge virus were obtained in 11 volunteers receiving IFN and 14 volunteers receiving placebo. Mean daily secretion weight and mean clinical scores were lower in those given IFN than in those given placebo - the differences were significant for clinical score on 2 days. The results suggest that IFN prophylaxis was less effective against influenza A than against rhinovirus.(ABSTRACT TRUNCATED AT 250 WORDS)

Serial samples of serum and nasopharyngeal washings were obtained from 43 volunteers given one of four rubella vaccines (HPV77.DE5, RA27/3, To-336, and Cendehill) and from nine naturally infected volunteers. Rubella-specific serum IgG was detected by radioimmunoassay for up to 12 years in all but one vaccinee, and booster responses occurred in 23.3% of vaccinees. Rubella-specific serum IgA was detected in 37 (90.2%) of 41 vaccinees one year after vaccination but in only five (45.5%) of 11 vaccinees tested 10-12 years after vaccination. Low levels of rubella-specific IgM detected by M-antibody capture radioimmunoassay persisted in seven volunteers--four of them HPV77.DE5 vaccinees--four more than one year after vaccination. Rubella-specific nasopharyngeal IgA was detected for up to five years after natural infection or vaccination with RA27/3 but for no longer than three years among Cendehill, HPV77.DE5, and To-336 vaccinees. Nasopharyngeal IgG antibodies were detected less frequently and at lower levels.

4',6-Dichloroflavan, a potent inhibitor of rhinovirus replication in tissue culture systems was tested in a double-blind, placebo-controlled volunteer trial for its protective efficacy against experimental rhinovirus infection. Dichloroflavan was administered intranasally as a 5 per cent w/v aqueous suspension (40 mg; 5 times per day) for 5 doses before and 21 doses after intranasal challenge with rhinovirus type 9, a virus type known to be highly sensitive to the drug when tested in tissue culture. A total of 49 volunteers were included in the efficacy analysis. Dichloroflavan did not produce any consistent or significant reduction in clinical or laboratory parameters of infection. Indeed there was some indication that treatment with the drug may have been associated with increased severity of clinical signs and symptoms. Dichloroflavan administered intranasally is not, therefore, of value in the prevention of human rhinovirus infection.