المفاهيم الأساسية
A single dose of the MVA-BN vaccine is moderately effective in preventing mpox infection, according to a real-world study in Ontario, Canada.
الملخص
The study aimed to estimate the real-world effectiveness of the MVA-BN vaccine against mpox infection. Researchers analyzed data from several linked databases in Ontario, Canada, including laboratory, vaccination, reportable diseases, and health administrative data.
The study population consisted of 9,803 men aged 18 years or older who had a history of being tested for syphilis, a laboratory-confirmed bacterial sexually transmitted infection (STI) in the previous year, or had filled a prescription for HIV pre-exposure prophylaxis in the previous year. The study period was from June to November 2022, during which time 691 people in Ontario were diagnosed with mpox.
Vaccinated men who had received the first dose of MVA-BN at least 15 days earlier were matched 1:1 with unvaccinated men based on age, geographical region, past HIV diagnosis, number of bacterial STI diagnoses, and receipt of any non-MVA-BN vaccine in the previous year. During a median follow-up of 85 days for vaccinated individuals and 86 days for unvaccinated individuals, there were 21 mpox infections in the vaccinated group and 50 in the unvaccinated group.
The study found that a single dose of MVA-BN was 58% effective in preventing mpox infection. The authors noted that this moderate effectiveness, combined with other preventive measures, can have a significant impact on reducing mpox transmission. They emphasized the importance of making the vaccine widely available and accessible, especially in regions experiencing large mpox outbreaks.
الإحصائيات
There were 691 people diagnosed with mpox in Ontario during the study period from June to November 2022.
The study population consisted of 9,803 men aged 18 years or older.
During the follow-up period, there were 21 mpox infections in the vaccinated group and 50 in the unvaccinated group.
The hazard ratio for infection in the vaccinated group compared to the unvaccinated group was 0.42, indicating a 58% vaccine effectiveness for a single dose of MVA-BN.
اقتباسات
"Data on this vaccine's effectiveness with just a single dose are useful for mobilizing vaccine efforts and in designing and implementing a multipronged prevention strategy to prevent outbreaks or reduce the size of outbreaks when they occur."
"When the mpox outbreak expanded into Canada, vaccines were made available and rapidly rolled out. The rollout of the first dose happened quickly to try and prevent as many infections as possible. There were no randomized clinical trials at the time to measure how well the vaccine worked, hence our study."
"In combination with other measures to help prevent infection, such as awareness of developing symptoms and reducing your contact when you have an infection, [MVA-BN] can have a really large impact."