There are vaccine-preventable diseases that have a higher incidence in cancer patients and are associated with a worse clinical evolution. But patients diagnosed with cancer can lose all or part of the immunity conferred by vaccines administered before diagnosis. That’s why the routine vaccination in cancer patients – and their household contacts – it is important to reduce morbidity and mortality in this vulnerable population.
However, cancer patients respond differently to vaccines given during the cancer treatment. When assessing the administration of each vaccine, the type of vaccine and the degree of immunosuppression of the patient.
There are different types of vaccines. Live or attenuated virus vaccines are contraindicated in immunosuppressed patients. However, those vaccines based on viral vectors but without replicative capacity, such as the vaccine Vaxzevria by AstraZeneca or the vaccine Janssen, can be safely administered in cancer patients or with immunosuppressive treatment, as well as inactivated, recombinant, protein subunit and nucleic acid vaccines such as DNA or RNA (Pfizer, Modern).
Vaccinate before immunosuppressive treatment
Data on the immune response to antiviral vaccination in cancer patients are generally scarce. Vaccination may be less effective in patients receiving antibodies against B cells or chemotherapy intensive, due to the depletion of B cells. But, given the risk / benefit profile, these patients should not be excluded from vaccination campaigns.
There is no contraindication for vaccination during cancer treatment, although in cases where possible it is recommended to do so before starting immunosuppressive treatment. If they are administered inactivated vaccines —Which inoculate only particles of the pathogen without the capacity to produce the disease—, it is recommended to vaccinate two weeks before the start of immunosuppressive treatment to obtain an optimal response.
If it is not possible to wait two weeks to start treatment, it is recommended to vaccinate and assess the need to re-administer the vaccines if the patient continues to be at high risk of infection.
It is not justified to delay the start of cancer treatment to vaccinate
The vaccination schedule must be updated before the start of immunosuppressive treatments, but delay is not justified the start of cancer treatment to vaccinate
What if treatment has already been started?
In the case of having already started the treatment, there are no specific data on the moment of the cycle in which it is preferable to administer the vaccine. The recommendations of scientific societies advocate doing so when it is logistically possible and do not delay Vaccination, due to the increased risk of severe disease and death from COVID-19 in cancer patients receiving immunosuppressive treatment.
More risk of severe covid-19
Cancer patients have a higher risk of severe disease and mortality with covid-19 infection than the population without cancer, especially those in active treatment, those with advanced cancer and patients with lung cancer Y hematologic malignancies.
Five years after diagnosis, the risk drops to equal that of the population without cancer
It seems that patients with solid tumors, particularly in the first year after diagnosis, their risk is also increased. However, the risk goes down that of the population without cancer five years after the cancer diagnosis.
From the Spanish Society of Oncology Medica (SEOM), in line with what is expressed by the European Society of Medical Oncology (ESMO), we state that, while there are limitations in the supply of vaccines, it will be necessary to prioritize cancer patients with active disease or antitumor treatment.
Vaccinate all cancer patients
However, the recommendation is maintained to vaccinate all patients diagnosed with cancer as soon as possible, including those free of disease and under follow-up.
In this way you will contribute to reduce the impact of covid-19 in cancer patients. The complications associated with the infection, the delays and interruptions of treatment in case of contracting the disease, and the fear of going to check-ups or complementary tests will decrease.
Vaccination will help reduce the impact of covid-19 on cancer patients
Covid-19 vaccines approved by the European Medicines Agency (EMA) are safe, and have been evaluated and tested in large numbers of people in clinical trials. Its efficacy in preventing COVID-19 of any severity is more than 70% in the adult and elderly population, with an acceptable safety profile. We do not yet have specific data on its ability to generate antibodies in cancer patients, with or without treatment, since this population was not included in the clinical trials developed.
Need for more data
At the moment there are not enough data to evaluate the interactions between cancer treatments and vaccination against COVID-19, but vaccination should be recommended in patients receiving immunosuppressive treatments due to the increased risk of morbidity and mortality in patients with cancer and COVID-19. Also because, as demonstrated in clinical trials, the covid-19 vaccine can provide higher levels of neutralizing antibodies than the infection itself.
There is still a lack of data to evaluate the interactions between cancer treatments and vaccination against covid-19
Information needs to be collected on an ongoing basis on the safety and efficacy of the COVID-19 vaccine in cancer patients, as well as its potential interactions with antineoplastic therapies.
Ana Santaballa She is coordinator of the SEOM Section for Prevention and Early Diagnosis and representative of SEOM in the Vaccine Group against covid-19 in the Ministry of Health and in the Federation of Scientific Medical Associations of Spain (FACME).
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