Nutritional Advice El MondoObjectives:
The eradication of wild and vaccine-derived poliovirus requires the global withdrawal of oral poliovirus vaccines (OPVs) and replacement with inactivated poliovirus vaccines (IPVs). The first phase of this effort was the withdrawal of the serotype 2 vaccine in April 2016, with a switch from trivalent OPVs to bivalent OPVs. Therefore, this review article (meta-analysis) has been conducted.
The aim of this review article is to produce comparative estimates of humoral and intestinal mucosal immunity associated with different routine immunisation schedules.
Study design:
This review article included 17 trials with a maximum of 8,279 evaluable infants were eligible for assessment of humoral immunity and 8 trials with 4,254 infants were eligible for intestinal immunity.
Only trials done outside western Europe or North America and without variation in age schedules (ie, age at administration of the vaccine) between study groups were included in this review article, because trials in high-income settings differ in vaccine immunogenicity and schedules from other settings and to ensure consistency within the network of trials.
Results and conclusions:
The investigators found for serotype 2 the risk ratio of seroconversion after 3 doses of bivalent oral poliovirus vaccines was 0.14 [95% CrI = 0.11-0.17, τ = 0.05, 95% CrI = 0.009-0.15] compared with 3 doses of trivalent oral poliovirus vaccines.
The investigators found for serotype 2 the addition of 1 or 2 full doses of an IPV after a bivalent OPV schedule increased the RR to 0.85 [95% CrI = 0.75-1.0] and 1.1 [95% CrI = 0.98-1.4], respectively.
However, the addition of an IPV to bivalent OPV schedules did not significantly increase intestinal immunity [RR = 0.33, 95% CrI = 0.18-0.61), compared with trivalent OPVs alone.
The investigators found for serotypes 1 and 3, there was susbstantial inconsistency and between-trial heterogeneity between direct and indirect effects. Therefore, only present pooled estmates on seroconversion were performed, which were at least 80% for serotype 1 and at least 88% for serotype 3 for all vaccine schedules.
The investigators concluded for WHO's polio eradication programme, the addition of one IPV dose for all birth cohorts should be prioritised to protect against paralysis caused by type 2 poliovirus. However, this inclusion will not prevent transmission or circulation in areas with faecal-oral transmission.
Original title:
Vaccine schedules and the effect on humoral and intestinal immunity against poliovirus: a systematic review and network meta-analysis by Macklin GR, Grassly NC, […], O'Reilly KM.
Link:
https://www.ncbi.nlm.nih.gov/pubmed/31350192
Additional information of El Mondo:
Find more information/studies on food fortification/malnutrition and vaccination right here.