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What Women Need to Know about COVID Vaccines

Get the facts on women and the J&J pause, pregnancy & fertility, and more...

As the investigation into the Johnson & Johnson vaccine highlights some serious questions about how vaccines affect women, we want to encourage critical questions and how to find answers from reliable sources.

Do vaccines affect men and women differently?

Yes, vaccines (and, in fact, lots of health-related things) affect women differently than men. The most obvious case of this is that the mild (normal) side effects of vaccines are often a bit stronger in women, like pain in the arm near the injection site, or mild flu-like symptoms in the day or two after the shot. The flip side of this is that women also tend to get less sick than men, on average, when they do have COVID. Scientists aren’t quite sure why women tend to have a stronger immune response, but it’s likely a mix of genes, hormones, and the dosing of vaccines. 

What do women need to know about the J&J pause?

The J&J pause came about after six women, ages 18-48, developed rare, but serious, blood clots with low platelets in the U.S. Since so few people have experienced this, it’s too early to say if it mostly affects women or certain age groups, but we can look to Europe, where a similar situation is playing out with the AstraZeneca vaccine. There, we do see that, while the blood clots do affect men, too, they affect women more often. The mRNA vaccines, like Pfizer or Moderna, show absolutely no patterns of severe side effects and no major concerns for women. 

For anyone who’s received a J&J vaccine in the past month, don’t panic! This clotting is very rare, around one in a million. Headache or flu-like symptoms in the day or two after your shot are normal and not worrisome. Keep an eye out for more serious symptoms that start six to 13 days after your shot. These include severe headache, leg pain, abdominal pain, or shortness of breath. If you notice any of those, call your doctor or dial 911 and be sure to mention that you recently got the J&J vaccine. 

Does the vaccine have side effects for pregnant women? 

There have been lots of rumors about pregnancy and fertility with the vaccine, in part because pregnant women weren’t included in the initial clinical trials. By now, hundreds of thousands of pregnant women worldwide have gotten vaccinated, and the evidence is strong that they are very safe for pregnant people. More than 86,000 pregnant women are tracking their health through the CDC’s v-Safe system after getting their vaccines in the US, and show absolutely no increased risk for birth defects, miscarriages, or any other pregnancy-related health issues. Pregnant women should talk to their OB to make a decision based on their specific health situation. 

Should people who want to get pregnant in the future be worried? Does it affect fertility?

There’s no evidence that vaccines affect fertility in any way. The mRNA or DNA used in vaccines don’t change mother or baby’s DNA in any way, which is one of the most common concerns people have about getting the COVID vaccine if they want to become pregnant. If you’re undergoing fertility treatment like IVF, you should chat with your doctor about the best time to get your vaccine, and make vaccination decisions with your medical team. 

Can the vaccine cause breast cancer?

No. There is no link between the vaccine and breast cancer. Some people have swollen lymph nodes as part of a normal immune response to the vaccine, as their bodies prepare  to fight any coronavirus they come into contact with in the future. Some women and their doctors’ have seen those swollen lymph nodes showing up on mammograms, which can cause some concern. They’re usually on the same side of your body where you got the shot.  If you get a mammogram within a few weeks after vaccination, be sure to mention it to your doctor. 

Does the risk of COVID outweigh any risk from vaccination? 

It’s important to remember that the risk to a mother and baby from actually getting COVID appears to be much higher than any potential risk from vaccination. Pregnant women who get very sick from COVID are at a higher risk of much more severe illness, are more likely to be hospitalized or die, and in some cases, are more likely to miscarry. Individual women should talk with their doctor about their own health and their baby’s, and make an informed decision, knowing that most major medical groups focused on obstetrics support vaccination for pregnant women who choose to do so.

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Disclaimer: This post is meant for general information and educational purposes only and does not constitute, and is not intended as, any form of medical, legal or regulatory advice or a recommendation or suggestion regarding the same.  No recipient of this information should act or refrain from acting on the basis of this information without first seeking legal advice from counsel in the relevant jurisdiction.