A reduced dose of pneumococcal conjugate vaccine seems to lower the risk of acquiring pneumonia and various other infections. It is stated that the infants given 2-3 primary doses of the 7-valent pneumococcal conjugate vaccine (PCV-7) appeared to have lower risk of developing certain infections, than the one’s who had not been vaccinated. This study was conducted by Elske J.M. van Gils, MD, of the University Medical Center Utrecht, the Netherlands, and colleagues.
This study has been conducted with the aim of better understanding reduced-dose vaccine schedules. Present vaccine schedule is evidently stated to be 3 + 1-dose schedule of PCV-7. This notably consists of 3 primary doses before 6 months of age, which is to be followed by a booster vaccination at age 2. Another reason for the exploration of reduced-dose schedules is stated to be the difficulties faced by developing countries to implement the 3 + 1-dose schedule.
For this purpose, the study investigators attempted to evaluate the effects of a 2-dose and 2 + 1-dose PCV schedule on nasopharyngeal (nasal part of the pharynx) pneumococcal carriage in infants. This analysis was conducted on a little more than 1,000 healthy newly born infants. These newborns were then believed to have been randomly categorized to either receive 2 PCV-7 doses at age 2 and 4 months; 2 + 1 PCV-7 doses at age 2, 4 and 11 months; or no dosage at all.
In the initial 6 months of life of all the children, not much difference was believed to have been noticed in vaccine serotype, non-vaccine serotype and overall pneumococcal carriage. However within 1 year, the vaccine serotype carriage rates were noted to be quite lesser in the vaccinated infants in comparison to their non-vaccinated counterparts. Furthermore, 1.5 years down the line, a greater decrease of vaccine serotype carriage was evidently noticed after 2 + 1-dose schedule and at 24 months after 2 primary doses, than the non-vaccinated infants.
“In conclusion, both 2-dose and 2 + 1-dose schedules of PCV-7 significantly reduce vaccine serotype pneumococcal carriage in children. This study supports future implementation of reduced-dose PCV-7 schedules,” state the study investigators.
The investigators were notably prompted to conduct this study due to the crowded infant vaccine schedules and less favorable cost-effectiveness calculations.
These findings have been published in JAMA.