Sir,

We would like to comment on the recent publication by Germann et al., on the association of initial coronavirus disease 2019 (COVID-19) vaccine hesitancy with subsequent vaccination among pregnant and postpartum individuals.¹ We read with interest that COVID-19 vaccination hesitation persisted throughout the peripartum period, and only a few people who were hesitant at baseline were later immunised. We agree that interventions to overcome vaccine reluctance in pregnancy are needed, and key to this is determining the elements that contribute to COVID-19 vaccine fear. Fundamental demographic characteristics have been documented as determinants in a report from India: the willingness to receive a COVID-19 vaccine was found to be significantly associated with female gender, younger age, absence of any personal illness, lower education level and current employment status.² Younger women, non-White ethnicity, and poorer socio-economic level were all linked to lower COVID-19 vaccination uptake in another multi-national investigation.³

In addition to demographic determinants, it should be noted that different time-periods may have different goals of vaccination: persons with underlying medical problems are usually the first group in early phases of immunisation in any country. Children and pregnant women are usually the last populations to be included in mass immunisation campaigns, once sufficient scientific data about the vaccine are gathered. In their study, Germann et al. used a rather short time-period (as low as 3 months) to determine the link between COVID-19 immunisation and vaccine reluctance in their study. According to a previous study in Hong Kong⁴ over more than 1 year of follow up, transient changes in variables related with COVID-19 vaccine reluctance were described: no statistically significant link between chronic medical illnesses and vaccine reluctance before and during the mass immunisation programme's deployment were seen in this study. In contrast, local residents with chronic medical illnesses were more hesitant 2–5 months into the programme.⁴ The local context of the outbreak, as well as new findings on vaccine efficacy and safety, which could lead to increased faith or disbelief in the COVID-19 vaccine, could all play a role. Hence, Xiao et al.⁴ emphasised the need for tracking COVID-19 vaccine reluctance and associated factors over time and altering promotional strategies accordingly to improve vaccination uptake.

To build an effective vaccination promotion programme, serial monitoring of vaccine uptake for subgroups with high priority – such as pregnant women – is essential.