Gardasil® as adjunctive therapy for respiratory papillomatosis at Red Cross Children’s Hospital, Cape Town

Background: Juvenile onset recurrent respiratory papillomatosis (JoRRP) is an incurable condition caused by human papilloma virus (HPV) types 6 and 11, often requiring repeated surgeries and in severe cases, tracheostomy. This imposes a significant socioeconomic burden on patients and families. Gardasil ® , a proven prophylactic HPV vaccine, is emerging as a potential adjuvant therapy. We studied its response on JoRRP patients at our center. Methods: We conducted a retrospective review at Red Cross War Memorial Children's Hospital from January 2015 to June 2022 on histologically confirmed JoRRP cases. Age at diagnosis, baseline and post-dosing Derkay-Coltrera (DC) scores (disease severity measure), inter-surgical intervals and tracheostomy, were collected. Results: Twenty-five of 30 confirmed cases were included. Average age at diagnosis was 60 months (about 5 years old), with HPV Type 6 in 40% and Type 11 in 48% of patients. All patients received at least one Gardasil ® dose, 84% received a second dose and 64% a third dose. Total population DC score decreased from an average of 17 (range: 4-34) pre-first dose to 8 (range: 0-16) after three doses, indicating a 50% reduction. Surgical intervals modestly increased. More significant improvements were seen in patients with aggressive forms of the disease. Conclusion: This is the first study in Southern Africa highlighting Gardasil ® as adjuvant therapy. Despite our limited sample size, new cases observed a linear reduction in DC scores and tracheostomy rates. Contribution: This suggests that Gardasil ® as adjuvant therapy has the potential to reduce disease severity and extend surgical intervals.