Newswise – A new international study led by Queen Mary University of London has shown that MPox infections (formerly known as monkeypox) are less severe in people who are vaccinated or have had a previous infection in 2022, adding to the significance and effectiveness of the vaccination.
The study, published in The Lancet Infectious Diseaseswas delivered by the SHARE-net collaborative and examined 38 MPox infections in 37 gay and bisexual men. Eight of the 38 were reinfections and 30 infections occurred after a full course of vaccination. Among vaccinated people, results showed that patients had fewer lesions (abnormal tissue such as a sore or rash), fewer mucosal diseases (diseases of the mucous membranes of the mouth and genitals), and minimal need for pain medication or hospitalization.
Symptom severity was monitored and assessed using the Mpox-SSS score developed during the multi-country outbreak in 2022. The Mpox-SSS score is a numerical score that takes into account seven different factors, including the number of lesions, the level of care required for the patient, the amount of pain medication required, the extent of mucosal areas affected and the presence of bacterial superinfection – so additional infections.
Using this rating system, it was possible to display and measure the severity. In those who were reinfected, the illness was less severe and required fewer painkillers compared to the first attack. In addition, fewer areas of the body were affected, while recovery was also faster. The first infection lasted 21 days (median), while the second infection lasted 15 days (median).
The study is the largest and only case series examining both reinfections and infections following full vaccination with Modified Vaccinia Ankara-Bavarian Nordic (MVA-BN).
As of May 2022, there have been more than 87,000 cases of human plague in 112 countries. The transmissions primarily affected sexually active gay and bisexual men and were caused by skin-to-skin contact and body fluid contact. As seen in SHARE-net’s two previous global case series published in The NEJM And The lancet, an infection often causes rashes, fever, and blisters. It can also lead to brain inflammation and seizures. Mortality rates are higher in people with advanced HIV disease up to 27% in the most immunocompromised group.
Neither natural immunity from a previous MPOX infection nor immunity after vaccination can prevent someone from becoming infected with the virus. However, the study shows that immunity to both reduces the severity.
said lead researcher Chloe Orkin, professor of HIV medicine at Queen Mary University of London and director of the SHARE collaboration: “This is good news and shows that infections are less serious and the need for hospitalization is reduced after vaccination.” This is clear evidence that vaccinations are an important tool to reduce morbidity and control further outbreaks.
“We must ensure global access to vaccinations and treatments if we are to contain this global outbreak, particularly in the African regions that have been hit hardest in the past and still lack access to vaccines or treatments for Mpox.”