Saturday, April 1, 2017

Yellow fever update

tw articles from the CDC:

one is a report about  last year's the epidemic in the Congo 

and this one is about "adverse effects of the vaccine". in that country:

during May 25–June 7, 2016, the DRC Ministry of Health administered approximately 240,000 doses of yellow fever vaccine to all persons aged ≥9 months during a mass vaccination campaign in Matadi, ....

a small number of people were followed and a few problems were found
Overall, 15 AEFIs were identified by active surveillance among approximately 2,800 patient records reviewed at the two targeted referral hospitals, including eight AEFIs previously reported during the immunization campaign (Table).

Two AEFIs were classified as serious and 13 as nonserious. The serious AEFIs comprised a spontaneous abortion that occurred after inadvertent administration of yellow vaccine early during an unrecognized pregnancy and a nonspecific gastrointestinal syndrome, both resulting in prolonged hospitalizations. Nonserious AEFIs included cutaneous allergic reactions, itching, fever, and injection site erythema. The incidences were 6.2 per 100,000 vaccine doses administered for all identified AEFIs and 0.8 for serious AEFIs.

Previous studies in African settings have found an expected AEFI rate of 8.2 per 100,000 yellow fever vaccine doses administered for all reported AEFIs and 0.4 for any serious AEFI (4).

there is a worry about the vaccine affecting the growing fetus causing defects butt

the cdc page on Yellow fever notes

Yellow fever vaccination has not been known to cause any birth defects when given to pregnant women. Yellow fever vaccine has been given to many pregnant women without any apparent adverse effects on the fetus. However, since yellow fever vaccine is a live virus vaccine, it poses a theoretical risk. While a two week delay between yellow fever vaccination and conception is probably adequate, a one month delay has been advocated as a more conservative approach. If a woman is inadvertently or of necessity vaccinated during pregnancy, she is unlikely to have any problems from the vaccine and her baby is very likely to be born healthy.

Pubmed has this abstract of a study on the risk of anomalies from the vaccine.

Seventy-four cases were analyzed, 58 with a completed follow-up. Pregnancies ended in 46 births, five voluntary abortions and seven spontaneous abortions. Three newborns had minor anomalies and two had major defects (ureteral stenosis and triphalangeal hallux). Although the sample is too small to rule out a moderate increased risk of adverse reproductive effect of YFV, it gives no argument for such an effect and should lead to reassure pregnant women who might be inadvertently vaccinated.

the rate of abnormalities is about the same as baseline.

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