There's a study that link's one particular flu vaccine to early miscarriages and it has many vaccine experts perplexed.
The study, paid for by the Center for Disease Control and Prevention (CDC), didn't pinpoint anything conclusive however, they found that 17 women have had miscarriages, which may be linked to the flu vaccination.
Yet, it is too soon to say that the vaccine actually caused the miscarriages.
"This study does not and cannot establish a casual relationship between repeated influenza vaccinations and miscarriage but further research is warranted," James Donohue, Edward Belongua of the Marshfield Clinic Research Institute, and his colleagues reported in the Journal Vaccine.
For the time being, pregnant women are still encouraged to get the flu vaccination. They and their unborn fetus are still at high risk from getting the flu; which has been confirmed by studies over a long period of time in tens of thousands of women.
Vaccine's are a touchy issue because there has been an influx of anti-vaxxers and people becoming increasingly vocal in stepping out against vaccinating children.
Public health experts are also concerned that the small group of anti-vaxxers will take advantage of the small study such as this one, as proof that vaccines are a danger to people.
"We don't want people to panic over this headline. Get your flu shot, it's safe," said Dr. Laura Riley, an obstetrician at Massachusetts General Hospital and Harvard Medical School.
Earlier, the same study was conducted by the same group of vaccine experts, and there was no evidence to support that the flu vaccine is a danger to expecting mothers.
"The open publication of the story shows there's no cover-up and proves that public health agencies are watching out for vaccine safety," said Dr. Amanda Cohn, senior adviser for vaccines at the CDC.
She continued to say that this study highlights how strong vaccine safety surveillance is.
"This is exactly the type of signal that we see because we do such a diligent job focusing on flu vaccine safety. Clearly, we need to study this more," she said.
The study included 485 women who had miscarriages in 2010, 2011 and 2012. They've compared them to 485 pregnant women who did not.
In their findings, they found that those who had been vaccinated against the flu 28 days before the miscarriage, and in the first trimester of pregnancy, were more likely to have had a miscarriage. When looking closely at the data, the Marshfield team found this only held amongst women who had also been vaccinated the previous flu season. And, it was only women who got the H1N1 vaccine; which was introduced in 2009.
“We didn’t expect to have these results at all,” said Donahue.