Acceptance of SARS-CoV-2 vaccination among French patients with cancer: a cross-sectional survey.

Vaccination against severe acute respiratory syndrome-related coronavirus-2 (SARS-CoV-2) represents an unprecedented hope in the fight against the global epidemic which has devastated the world. International efforts in the development and approval of several vaccines led to the start of vaccination campaigns less than 1 year after the emergence of this new pandemic. The main trials showed efficacy in >90% of individuals and a favorable safety profile in healthy but also older populations. Patients with cancer have been shown to have a variable but confirmed higher risk of severe coronavirus disease 2019 (COVID-19) and should be a target population for vaccination, despite that they were paradoxically excluded from the first trials.

In order to better prepare the future vaccination campaign among patients treated or monitored for cancer, we measured the acceptability towards the anti-SARS-CoV-2 vaccination in this specific population. We conducted a cross-sectional survey with an anonymous self-administered paper questionnaire delivered to every admitted ambulatory patient in four French cancer centers from 11 November 2020 to 12 December 2020. Among the 1244 delivered questionnaires, 999 analyzable forms were returned (80.3%). The population included 56.1% women and the median age was 67 (range 18-97) years. Among these patients, 47% were under active treatment (chemo- or immunotherapy and/or radiotherapy), 40% were under surveillance and 13% were under hormonal therapy. The majority had received an influenza vaccine in 2020 (54.3%) or in previous years (52.2%). A very small proportion of respondents declared they had contracted COVID-19 (2.8%).

Among the respondents, 536 (53.7%) reported their intent to be vaccinated as soon as the vaccine was available, whereas 297 (29.7%) considered they were not ready yet but likely to change their mind. Only 166 patients reported to definitely refuse vaccination (16.6%).

For patients in favor of vaccination, the main reasons they reported were fear about their health (76.9%), the desire to protect their relatives (49.9%), the duty for collective responsibility (45.6%) and finally the wish to return to a normal life (38.7%). For patients unsure about vaccination, the arguments that could convince them to be vaccinated were to obtain more information on efficacy (59.4%), on safety (50.3%), on the type of vaccine administered (35.2%) and only 7.4% for collective responsibility or return to a normal life. For patients who did not support vaccination, the main reasons were the lack of confidence in the scientific results (88%), fear of side-effects (30%) and believing COVID to be benign for few respondents (3.6%).

The predictors for vaccination acceptance in multivariate analysis were history of influenza vaccination [odds ratio (OR) 3.8; 95% confidence interval (CI) 2.9-5.1, P < 0.001], male sex (OR 1.8; 95% CI 1.4-2.4 P < 0.001) and age >69 years (OR 1.4; 95% CI 1-1.8, P < 0.05) (Figure 1 ).

Figure 1

Predictors of SARS-CoV-2 vaccination acceptance.

Prior flu vac.: prior seasonal influenza vaccination.

The oncologist was considered qualified to advise the patients for a majority of them (59%), mainly the ‘yes’ (62.9%) or ‘why not’ (63.3%) respondents contrasting with 38.6% of the ‘no’ (P < 0.001). In contrast, personal judgment was the main source of reliable information among the ‘no’ respondents (45.8%) in comparison with ‘yes’ (12.7%) or the ‘why not’ respondents (16.5%) (P < 0.001).

Our study shows the willingness of a majority of patients in active cancer care or on surveillance to be vaccinated against COVID-19, mainly considering themselves to be at risk.

Unfortunately, no data are available yet to formally assess the efficacy of COVID-19 vaccine in cancer patients. The immune response could be reduced as it has already been shown for influenza inactivated vaccines in patients undergoing chemotherapy or targeted anti-CD-20 therapy, with better coverage, however, by adding a second dose. The high efficacy of messenger RNA vaccines favored by the booster dose allows us to hope for a sufficient protective efficacy for a majority of patients, associated a priori with an equal tolerance to the general population, though to be confirmed. Studies with stratification according to the type of treatment and the type of vaccine are a priority for the international oncology community.