Influenza vaccine: A viable option to protect pregnant women and infants from seasonal flu: A retrospective hospital-based study in India.

BACKGROUND

Influenza is a highly contagious disease with global annual outbreaks of 3-5 million severe cases and 0.25-0.5 million deaths. The risk is greater in pregnant women that results in high morbidity and mortality.

OBJECTIVE

The objective of this study was to see the efficacy of influenza vaccine on pregnant women and their newborn upto 6 months.

METHOD

This was a retrospective study (January 2016-March 2018). Records of 346 pregnant women were included in this study (vaccinated: 288; unvaccinated: 58). Women and infants were categorised into Category A, B or C according to the guidelines issued by the Ministry of Health and Family Welfare, India on influenza.

RESULTS

The groups were comparable with respect to baseline characteristics. Greater number of women received influenza vaccine during the first trimester (n = 117). During the gestation period, majority of the women in the vaccinated group were symptom-free compared with the unvaccinated (92% vs 70.7%). Also, none of the vaccinated women were categorised into category C compared with one who was laboratory tested positive for influenza in the unvaccinated group. Similar results were seen postpartum and more number of infants remained symptom-free in the vaccinated group compared with unvaccinated (69.3% vs 25.9%). More number of infants were born pre-term in the unvaccinated group compared with vaccinated (15.5% vs 8.6%).

CONCLUSIONS

Immunisation with influenza vaccine in any trimester during pregnancy was found to protect the mother and infants upto 6 months of age against seasonal influenza without significant maternal adverse effects. In order to improve vaccination rates, there must be a national vaccination policy and incorporation of maternal immunisation in standard antenatal care.