Breakthrough Covid infections on a rise among cancer patients

April 15, 2022 0 By Team FM

Remaining adhered to all protective measures and getting inoculated with variant specific vaccines against Covid-19 are still high priorities for protecting the immunocompromised. For cancer patients, in particular, Covid-19 poses a very high risk due to their often compromised immune systems, weakened by therapy or disease. A recent study led by Medical University Vienna showed that, due to Omicron, there is a significantly increasing number of breakthrough infections in people with cancer, especially while they are undergoing cancer therapy. The research, published in the journal Cancer Cell, found that a total of 950 of the 3,959 cancer patients (24%), who have been under treatment at the University Hospital Vienna and Franz Tappeiner Hospital in Merano, Italy, between February 2020 and February 2022, had become infected with the SARS-CoV-2 virus. At least 85 percent of these 3959 patients were inoculated with one of the Covid vaccines approved in Europe.   

The MedUni Vienna study showed that the number of breakthrough infections increased significantly with the emergence of the Omicron variant in January 2022. Seventy percent of infected patients were vaccinated. Thus, the risk of vaccine breakthrough for cancer patients due to Omicron tripled compared with the Delta variant that prevailed between October and December. Breakthrough infections were significantly more common among those who were undergoing systemic treatment than among those without ongoing cancer therapy, the research showed.

To obtain reasons for the higher rate of breakthrough infections with Omicron compared to Delta, the researchers examined, among other things, the concentration of protective antibodies in the blood in samples from 78 cancer patients and 25 healthy individuals. Strikingly, both in people with solid tumours and blood cancers, there was greatly reduced inhibition of the Omicron variant by specific vaccine antibodies as compared to people without cancer. However, there was also a trend toward shorter hospital stays for vaccinated versus unvaccinated patients. In addition, breakthrough infections only required intensive medical care in rare cases.

However, the researchers strongly recommend that protective measures are still very important for cancer patients. 

“The increasing rates of breakthrough infections and hospitalisations of vaccinated cancer patients associated with Omicron underscore the need for further protective measures not only to effectively combat the ongoing pandemic, but also to prepare for the potential emergence of additional Sars-CoV-2 variants,” says Dr Matthias Preusser, Head of the Division of Oncology at the Department of Medicine at MedUni Vienna and University Hospital Vienna. 

Dr Preusser added that vaccines adapted to the particular Sars-CoV-2 variant could help to better protect cancer patients and maintain life-sustaining cancer treatment during the pandemic.