The cross-sectional study was conducted at Jaya Arogya Group of Hospitals (JAH) which is a government sector tertiary care hospital associated with Gajra Raja Medical College, Gwalior, Madhya Pradesh, India. It provides wide range of services from super-specialty care to routine services including Immunisation. The duration of the study was from 1^st February 2020 to 31^st August 2020. The present study utilised data collected from the patient record available from the Out Patient Department (OPD) register.

Inclusion and Exclusion criteria: All the children who visited the Immunisation OPD during the study period were included to show the trend of vaccination. Thus, a total of 817 children were included in the study. The OPD was closed in April 2020 due to lockdown so no data was available for the April month hence these children were excluded.

Purposive sampling method was used to collect the data. A written permission (I.No.596-A/PSM/2020/16/09/2020) was obtained from the Head of the Department, Preventive and Social Medicine, Gajra Raja Medical college Gwalior, India, for collection of data and to conduct the study.

There is no standard definition available for delayed vaccination, hence considering other studies [15,16], operational definition for “Delayed vaccination” for each vaccine was defined as administration of the vaccine dose after two weeks of the minimum age recommended by the national Immunisation schedule in India.

In the study, Penta 1 series included: Pentavalent-1, IPV-1 (Inactivated Polio Vaccine), PCV-1(Pneumococcal Conjugate Vaccine), OPV-1 (Oral Polio Vaccine-1) and Rotavirus-1. Penta-2 series included: Pentavalent-2, Rotavirus-2 and OPV-2. Penta-3 series includes: Pentavalent-3, OPV-3, Rotavirus-3, PCV-2 and IPV-2. MR-1 includes (Measles Rubella). Booster-I included: MR-2, Diphtheria Pertussis Tetanus (DPT) booster-1 and OPV-booster dose and Booster-II includes DPT-2 and OPV booster dose.

The collected data was coded and entered into Microsoft Excel version-2007. Descriptive statistics (frequency, percentage, mean and standard deviation) were calculated. Chi-square test was applied to test association. To show the time trend, a line diagram was used. The p-value was calculated at 5% level of significance.

The mean age of children was 7.46 months (±13.60). The median age was 2.50 months (1.5-4.5). Among the 817 children that were included, male children were 61.1% (499) while females 38.9% (318).

The children vaccinated for BCG, penta-1 series, penta-2 series, penta-3 series, MR-1, Booster-1dose, Booster-II dose were 10.6%, 36.4%, 17.4%, 12.2%, 6.5%, 11.8% and 5.1%, respectively [Table/Fig-1]. In the month of February 22.4% children came for vaccination. From month of March, Immunisation coverage declined from 17.75% to 11.51% in June. It was also seen that after the month of February the number of children for vaccination declined by a great extent reaching to its lowest count i.e., 27 in the month of May and regaining its peak in August [Table/Fig-2]. In the age group 0-2 months and 2-4 months, maximum participants reported for Immunisation i.e., 43.3% and 31.7%, respectively.

[Table/Fig-2]:

Monthly distribution of vaccination of children.

Among males, the maximum number received the Penta-1 series vaccine (35.5%), while the maximum number of the female child also received the same (37.7%). Minimum number of children reported for vaccination of Booster-II dose. In the 0-2 month age group, 75.4% children came for Penta-1 series vaccination. In the month of February, vaccination for BCG, Penta-1, Penta-2, Penta-3, MR-1, Booster-I and Booster-II were 25.7%, 36.1%, 14.2%, 10.9%, 2.7%, 7.1% and 3.3%, respectively. Similarly, for the rest of the months, percentage distribution for different vaccines is shown in [Table/Fig-1].

In this study, total of 51 (6.2%) children were found to be delayed for vaccination. Among males, the delay was seen in 7.2% while in females delay was 4.7%. In the age group of 0-2 months, there was no delay while the maximum delay was seen in 4-6 months of age group. Delay in vaccination was found to be significantly distributed in age groups. Children who were delayed for vaccination received Penta-1 series-31 (10.4%), Penta-2 series-18 (12.7%), Penta-3 series-01 (1.0%), MR-1-01 (1.9%). Vaccination, for which children were scheduled was significantly associated with the delay. The maximum monthly delay was seen in May and June which was 18.5% and 20.2%, respectively, while the minimum delay was seen in August (1.8%) [Table/Fig-3].

The delay that was seen for the Penta-2 series, Penta 3 series, and MR-1 was 43.1%, 51.0% and 5.9% respectively and the difference was statistically significant (p=0.005) [Table/Fig-4]. Monthly distribution for the delay in vaccination showed that June witnessed the highest number of delay (37.30%) [Table/Fig-5].

[Table/Fig-5]:

Monthly distribution of delayed children.

Recent reports worldwide suggest that routine childhood Immunisation coverage might have decreased during the COVID-19 pandemic [17,18]. In this study, it was seen that total 817 children came for Immunisation during 6 months. The number of children in the month of February was 22.4% which started declining in the subsequent months, reaching its lowest in the month of May i.e., 3.3%. Causes of this decrease/interrupted Immunisations are due to parents’ fear, restrictions of movement/lockdown policies, changing priorities for COVID-19 among health-care personnel and logistics delivery issues (i.e., vaccine transport delays) [5,19]. The World Health Organisation (WHO), UNICEF, and Global Alliance for Vaccines and Immunisation (GAVI), the Vaccine Alliance have reported that routine Immunisation programs have been substantially disrupted in at least 68 countries, affecting around 80 million children. Of the 129 countries in which data were available, more than half reported moderate to severe disruptions or total suspension of vaccination services during March-April 2020 [5]. There was a full cessation of routine Immunisations from April 1-15,2020 in Vietnam. In Pakistan, polio catch-up Immunisation campaigns were postponed until June 1^st, 2020 [20]. The situation is quite similar to this study where Immunisation OPD was closed in April due to total lockdown.

A decline in the routine Immunisation of about 14.4% was observed in this study during the initial days of lockdown (i.e., from March to May) which is consistent with a study in England where the number of Measles, Mumps, Rubella (MMR) vaccine delivered fell by 20% during the first 3 weeks of the lockdown [21] and similarly in Indonesia about 19.7% drop in MMR vaccination in April 2020 was seen [22].

Out of all the children, majority received Pentavalent-1 series vaccine (36.4%), this is due to the fact that the percentage of children in the age group of 0-2 months was also maximum (43.3%). Number of children both male and female receiving DPT-2 booster vaccine was minimum, similar findings were seen in a study done by Singh J and Neki NS, where number of children receiving DPT-2 booster vaccine was minimum (9.27%) [23].

Another important observation in this study was delayed vaccination which was found in 6.2% children. This could be due to lockdown policies implemented by the government during initial phase of COVID-19 and fear of parents about potentially exposing their children to COVID-19 during routine follow-up visits [5]. Delay in vaccination is significantly associated with monthly distribution of the children reporting for vaccination. Maximum delay was seen in the month of June (20.2%) followed by month of May (18.5%). The possible reason may be due to closed Immunisation OPD in April that led to piling up of children due for vaccination and starting of the unlock-1 period from 1^st June 2020 which led to a comparative rise in the number of children coming to immunisation OPD. The minimum delay was seen in August (1.8%) as the number of children coming for vaccination started increasing.

In fact, the number of children vaccinated in August was maximum (224) when compared to other months. This shows that routine childhood Immunisation services came back to its normal pace after a sudden dip during the lockdown phase. A similar pattern of routine childhood immunisation was seen in a study done in the UK by McDonald HI et al., [21] wherein the 3 weeks after the introduction of full physical distancing measures (weeks 13 to 15), hexavalent vaccination was 6.7% lower and MMR vaccination 19.8% lower than in 2019, although physical distancing measures remained unchanged nationally throughout the rest of the study period, vaccination counts were higher in weeks 16 and 17 of the year 2020 than for the same weeks in 2019 for both hexavalent and MMR vaccines. If we look at the vaccine-specific delay, maximum delay was seen for pentavalent 3 series and pentavalent 2 series vaccines as most of the children delayed for vaccination was in the age group of 2-4 months while no delay was seen for BCG and pentavalent 1 series vaccine because whenever a child below 1 year of age who is delayed for age-specific vaccination came to OPD, BCG and Penta 1 series vaccine is given to the child irrespective of his/her age-specific due vaccine status. Since this study was conducted in a tertiary care hospital so 100% of newborn children would receive birth dose vaccination and this again added to a 0% delay in BCG vaccination. It seems that the delay observed was a planned one rather than lack of adherence to routine immunisation program. One plausible explanation is that covid-19 messaging about staying home initially overwhelmed the message that the Immunisation program was to remain operating as usual [21].

There was no direct contact with the participants or the care givers so it was not possible to incorporate all the socio-demographic variables of the study participants. The data was taken from the OPD register hence any possible erroneous entries made at the time of vaccination could not be ruled out.

The vaccination during the lockdown phase of the COVID-19 pandemic had declined but after June 2020 vaccination again started showing a positive upward trend which is critical to maintaining momentum on routine childhood Immunisation. The study recommends that to prevent overcrowding, immunisation sessions should be conducted with fixed prior appointments while ensuring health workers’ safety. Catch-up campaigns should be organised with all necessary safety precautions. Vaccine timeliness should be given utmost priority, focused strategies to be implemented to achieve a significant and sustainable increase in vaccinations during pandemics.