Introduction: Mild and moderate Adverse Events Following Immunization (AEFI) against Rotavirus has not received much attention when the vaccine is administered regardless of recommended age restriction. Objectives: To describe the behavior of mild and moderate AEFI in immunized subjects against Rotavirus, in who age restriction period had not been considered. Methods: A case-control study in which we included immunized patients with monovalent oral vaccine against rotavirus and divided them into two groups: 1) Infants who received RV1 vaccine without considering the recommended period, and 2) Infants who were vaccinated with the recommended schedule. Results: From the total doses, 143/1894 (7.5%) were administered outside the restriction period. The most frequent AEFIs with the first dose were purpura, polypnea, and rhinorrhea; For the second dose: purpura, bloody stools, irritability and rhinorrhea. Conclusions: This study shows the benefits from vaccination regardless of age restriction are more beneficial compared to the possible risks of AEFI.
Rotavirus vaccine lowers worldwide mortality against acute diarrheal disease by approximately 50%, tracking these results over the time [
Two main concerns for immunizers is vaccination against RV increases AEFI risk, especially intestinal intussusception [
Current evidence has shown that the administration period can be extended [
Mild and moderate AEFIs haven’t been fully evaluated if the vaccine is administered without considering age restriction.
Our purpose was to describe if vaccinated infants, without taking into consideration age administration, developed AEFIs.
We conducted a case control study in which we included those patients who came to Preventive Medicine Department in High Specialty Hospital Mexican Oil Company for the administration of the monovalent oral vaccine against rotavirus (RV1) from 2008-2013. The patients came to the pediatric consult or emergency department up to 54 days after being immunized. We reviewed electronic clinical records to obtain reason of consult, and later we classified the AEFI into “mild” or “moderate” according to literature definitions [
The evaluation of the clinical data between groups was performed by the difference of proportions. The numerators were obtained from the population databases from an institutional medical census. The doses of vaccines applied were reviewed from the databases of the Preventive Medicine Service.
Between 2008 and 2013, 1894 doses of RV1 vaccine were administrated: 1014 for the first dose and 880 for the second dose, resulting in an 86.6% completion of rotavirus vaccine schedule.
From the total number of the doses, 143 (7.5%) were administrated outside age restriction; 62/143 (43.3%) for the first dose, and 81/143 (56.6%) for the second dose.
For the first dose, median age of vaccination was 9.3 weeks (Group 1) versus 16.3 weeks (Group 2). For the second dose, the median was 35 weeks and 27.3 weeks, respectively.
Variable | First dose | p | Second dose | p | ||||||
---|---|---|---|---|---|---|---|---|---|---|
Out of restriction | % | Within restriction | % | Out of restriction | % | Within restriction | % | |||
Abdominal pain | 1 | 16.6 | 15 | 17.6 | >0.05 | 1 | 12.5 | 11 | 17.4 | <0.05 |
Vomit | 2 | 33.3 | 24 | 28.2 | >0.05 | 2 | 25 | 19 | 30.1 | >0.05 |
Fever | 1 | 16.6 | 18 | 21.1 | >0.05 | 2 | 25 | 15 | 23.8 | >0.05 |
Purpura | 1 | 16.6 | 5 | 5.8 | <0.05 | 1 | 12.5 | 4 | 6.3 | <0.05 |
Polipnea | 1 | 16.6 | 8 | 9.4 | <0.05 | 1 | 12.5 | 6 | 9.5 | >0.05 |
Diarrhea | 1 | 16.6 | 11 | 12.9 | >0.05 | 1 | 12.5 | 8 | 12.6 | >0.05 |
Bloody stools | 1 | 16.6 | 2 | 2.35 | <0.05 | 1 | 12.5 | 2 | 3.1 | <0.05 |
Irritability | 1 | 16.6 | 14 | 16.4 | >0.05 | 2 | 25 | 11 | 17.4 | <0.05 |
Rhinorrhea | 1 | 16.6 | 5 | 5.8 | <0.05 | 1 | 12.5 | 4 | 6.3 | <0.05 |
Dehydration | 1 | 16.6 | 11 | 12.9 | >0.05 | 1 | 12.5 | 9 | 14.2 | >0.05 |
When we evaluated the 54 day period after vaccination, we found that 6 (0.63%) of immunized infants from group 2, were hospitalized, in contrast with none of the group 1. From the second dose, only 4 infants (0.5%) from group 2 were admitted to the hospital and none of the infants vaccinated in the recommended range. The mean number of consults to the emergency department of pediatrics was similar in both groups and for both doses (8 vs. 8.3 and 8.4 vs. 7.1). Comparing median diarrheic episodes as a reason for consult, there was no significative difference between groups (3 vs. 2 and 3 vs. 4 respectively).
The most frequently AEFI found after the first dose were: purpura, polypnea, rhinorrhea; and for the second dose: purpura, bloody stools, irritability and rhinorrhea (see
In Mexico, the AEFI surveillance against rotavirus begun in 2007, based on an adapted system to the international recommendations, with the purpose that detection of these events could be useful to the immunizers and other health care workers [
Part of this evaluation requires a follow up to monitor for mild and moderate AEFIs. Vaccine resistance among users can create rejection to its administration, disqualifying their validity [
In our country it was previously reported that vomiting, bloody stools, fever and dehydration were the most frequent AEFIs [
These results support that extending the age administration for RV1 vaccination does more good than the risks of its application after the restriction age. In a closed and captive population, such as the Mexican Oil Company health system, age restrictions for the rotavirus vaccine offer a potential incentive for timely vaccination, potentially allowing longer-term benefits beyond the prevention of rotavirus disease. However, the reasons for the delay in vaccination in developing countries are complex and it is not known whether a policy of restricting the first dose of Rotavirus would be a sufficient motivation factor to improve the timeliness of vaccination [
The absence of vaccination in children less than one year of age reduces the health benefits of immunization policies substantially. The deaths caused by unapplied intervention can be perceived as a tragedy [
The importance of performing these evaluations consists in the few possibilities we have to evaluate this population, because it would be unethical to develop a research study in which we left one group unvaccinated according to the vaccine schedule.
Taking in consideration Patel, et al. proposal modeling study, we performed our research study with patients from our health care system, which are a captive population.
Our analysis suggests that in low- and middle-income countries the additional lives saved by removing age restrictions for rotavirus vaccination would far outnumber the potential excess vaccine-associated intussusception deaths.
There is no conflict of interest regarding this research.
Reyna-Figueroa, J., Bercholc-Urinowsky, I.J., Cardoso-Yah, G., Vazquez-Alvarado, R.P., Ramos-López, D., Campos-Romero, F.H., Handelsman, C. and Limón-Rojas, A.E. (2017) Evaluation of Adverse Events Following Immunization against Rotavirus Regardless of Recommend- ed Age Restriction. Journal of Biosciences and Medicines, 5, 78-82. https://doi.org/10.4236/jbm.2017.58006