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In October 2018 the US Food and Drug Administration expanded the approved use of the human papillomavirus (HPV) vaccine (Gardasil 9) to adults aged 27 through 45.1 In June 2019, the Centers for Disease Control and Prevention’s Advisory Committee on Immunization Practices (ACIP) voted to extend catch-up HPV vaccination to include all individuals through age 26 and to catch-up HPV vaccination, based on shared clinical decision making, for all adults aged 27 through 45.2 HPV viruses are associated with cervical cancer, as well as several other forms of cancer that affect both women and men. Approval for the expanded use of the HPV vaccine was based on data of the vaccine’s use in women.1,3
Unfortunately, adult immunization rates, including among pregnant women, do not equal the higher rates in childhood vaccine uptake, according to Kevin A. Ault, MD, and colleagues. Less than half of women (46.6%) receive influenza vaccination prior to and during pregnancy, for instance.4 Dr. Ault has identified the need for an “immunization champion”—someone who can manage one-on-one conversations with patients in the office setting to enhance the acceptance and uptake of adult and maternal vaccines.
OBG Management:
Dr. Kevin A. Ault, MD: The main thing a practice needs to do is to identify someone who is interested, and this person does not have to be a physician. In fact, he or she can frequently be a member of your nursing staff or office staff. And the word “champion” involves a lot of nuts and bolts: such details as how do you store the vaccine, how do you keep track of it, where are the vaccine information statements filed, where can the provider get more information if there is a question about contraindications? One person should organize all these details. The mechanics of vaccine administration are important as well, as the research shows that the more automated the process is, the better and more smoothly it is carried out. There is certainly a role for “standing orders” for adult vaccines.
OBG Management: What communication approach do you take with patients to enhance vaccination acceptance and uptake?
Dr. Ault: There are multiple research studies that show that provider recommendation is the most important way to get both nonpregnant and pregnant adults to receive vaccinations. Take the pertussis vaccine (the whooping cough booster) as an example. It is a relatively new vaccine recommendation during pregnancy. Your approach is relatively straightforward when explaining it to pregnant women. Make the point that we do not want your newborn to have whooping cough in those first few months of life before the newborn or infant vaccine becomes effective. Most people know they had a whooping cough, or pertussis, vaccine when they were younger, and the concept of the booster is well-known to patients. You should explain that the maternal antibodies pass through the placenta to the fetus, and they provide benefit for the first few months of life after birth.
The pertussis vaccine does not have all the “baggage” of the influenza vaccine. Talking with patients about the flu vaccine may present more challenges. Typically, each fall there is a popular press publication that explains “the 10, or 20, most common myths about influenza vaccine.” Every fall I try to find one of those articles, print it out, and even carry it in my jacket pocket and talk about all the myths. For example, there is a myth that “I always get sick when I get the flu shot.” Obstetricians should be giving patients an inactivated vaccine that does not contain any live flu virus. We should be able to explain to patients, your arm will be sore, and you may have some muscle aches, but you will not have the flu from your flu vaccine.
I think another reason that pregnant women do not always take the flu vaccine is that we do not yet have normalized influenza vaccination in the adult population. Women in their twenties and thirties are generally very healthy and have other concerns when they are pregnant, and they perhaps do not realize that they are more vulnerable to devastating effects of influenza while pregnant. Additionally, maternal influenza vaccination does protect the newborn from flu for the first few months. It is vital that those patients who are due during the dark winter months, when the flu is in season, get vaccinated.
Combat the myths and tell your patients the reasons for flu vaccination. Also tell them that you got your flu shot, like most health care professionals do every fall. You should be prepared to talk about safety. There are wonderful safety data, even some published in 2017 and 2018, about pertussis vaccine safety during pregnancy, and it is very reassuring to patients. For flu, the idea of vaccinating women against influenza has been around for decades, and so we have reliable information about that as well. Certainly, the risks are very minor, and the benefits are potentially huge for the pregnant woman and for the newborn.
OBG Management: When do you recommend that ObGyns administer the flu vaccine for pregnant women?
Dr. Ault: There are 2 issues to this question: when throughout the year and when during the pregnancy to administer the vaccine. First, you want to give the flu vaccine during the usual influenza season during the fall. As soon as the vaccine is available, you will recommend that pregnant women, even in their late pregnancy, get vaccinated so that their newborns who are 3 and 4 months old in the peak flu season are protected. The patients who deliver over the summer, who are coming in for their postpartum visit during the fall, should be getting vaccinated as well, because they are still vulnerable to influenza and pneumonia for several months postpartum.
If you have patients that come in for preconception visits, you could say: “Let’s get this out of the way. You could be pregnant by the time flu season really gets cranked up.”
Because we see patients 10 or 12 times during pregnancy, we certainly have plenty of opportunities to educate patients about and administer the flu vaccine. There are older data that demonstrate if patients do not get the flu vaccine done during early pregnancy, the opportunity may be lost. It is different now because there is more emphasis on vaccinating all adults. Your patients certainly can get their vaccine at the pharmacy or at their primary care doctor; however, delaying until later pregnancy usually means not getting the vaccine.
I would like to address one recent study from Donahue and colleagues that showed a potentially increased risk of miscarriage with flu vaccination.5 That study was an anomaly, as there are many other studies into the issue. Yes, there are not a lot of first trimester data, but there are other studies, including studies by the same authors, that did not find this to be the case.6-10
The 2017 study by Donahue and colleagues was an anomaly because the group of women they were vaccinating were already at high risk for miscarriage. The women were older, had diabetes, or a history of miscarriages. There is selection bias in the study because the pregnant women who were vaccinated were already at higher risk for miscarriage. The Centers for Disease Control and Prevention and the American College of Obstetricians and Gynecologists are not going to change any of their recommendations based on a single study that is different than our previous data.11
Current recommended adult (anyone over 18 years old) immunization schedule
ACOG Immunization Champions (ACOG members who have demonstrated exceptional progress in increasing immunization rates among adults and pregnant women in their communities through leadership, innovation, collaboration, and educational activities aimed at following ACOG and CDC guidance.)
Summary of Maternal Immunization Recommendations is a provider resource from ACOG and the Centers for Disease Control and Prevention.
Maternal Immunization Toolkit contains materials, including the Vaccines During Pregnancy Poster, to support ObGyns on recommending the influenza vaccine and the Tdap vaccine to all pregnant patients.
Influenza Immunization During Pregnancy Toolkit
CDC vaccine schedules app for health care providers
CDC Vaccine Information Statements (available for clinician or patient download)
- FDA approves expanded use of Gardasil 9 to include individuals 27 through 45 years old [press release]. Washington, DC: Food and Drug Administration; October 5, 2018.
- Color/Blue2. Splete H. ACIP extends HPV vaccine coverage. June 27, 2019. https://www.mdedge.com/obgyn/article/203656/vaccines/acip-extends-hpv-vaccine-coverage. Accessed July 5, 2019.
- Levy BS, Downs Jr L. The HPV vaccine is now recommended for adults aged 27–45: Counseling implications. OBG Manag. 2019;31(1):9-11.
- Frew PM, Randall LA, Malik F, et al. Clinician perspectives on strategies to improve patient maternal immunization acceptability in obstetrics and gynecology practice settings. Hum Vaccin Immunother. 2018;14(7):1548–1557.
- Donahue JG, Kieke BA, King JP, et al. Association of spontaneous abortion with receipt of inactivated influenza vaccine containing H1N1pdm09 in 2010-11 and 2011-12. Vaccine. 2017;35(40):5314-5322.
- Moro PL, Broder K, Zheteyeva Y, et al. Adverse events in pregnant women following administration of trivalent inactivated influenza vaccine and live attenuated influenza vaccine in the Vaccine Adverse Event Reporting System, 1990-2009. Am J Obstet Gynecol. 2011;204:146.e1-146.e7.
- Irving SA, Kieke BA, Donahue JG, et al; Vaccine Safety Datalink. Trivalent inactivated influenza vaccine and spontaneous abortion. 2013;121:159-165.
- Kharbanda EO, Vazquez-Benitez G, Lipkind H, et al; Vaccine Safety Datalink Team. Inactivated influenza vaccine during pregnancy and risks for adverse obstetric events. Obstet Gynecol. 2013;122:659-667.
- Nordin JD, Kharbanda EO, Vazquez-Benitez G, et al; Vaccine Safety Datalink. Maternal Influenza vaccine and risks for preterm or small for gestational age birth. J Pediatrics. 2014;164:1051-1057.e2.
- Kharbanda EO, Vazquez-Benitez G, Romitti PA, et al; Vaccine Safety Datalink. First trimester influenza vaccination and risks for major structural birth defects in offspring. 2017;187:234-239.e4.
- Flu vaccination and possible safety signal. CDC website. https://www.cdc.gov/flu/professionals/vaccination/vaccination-possible-safety-signal.html. Last reviewed September 13, 2017. Accessed May 15, 2019.
In October 2018 the US Food and Drug Administration expanded the approved use of the human papillomavirus (HPV) vaccine (Gardasil 9) to adults aged 27 through 45.1 In June 2019, the Centers for Disease Control and Prevention’s Advisory Committee on Immunization Practices (ACIP) voted to extend catch-up HPV vaccination to include all individuals through age 26 and to catch-up HPV vaccination, based on shared clinical decision making, for all adults aged 27 through 45.2 HPV viruses are associated with cervical cancer, as well as several other forms of cancer that affect both women and men. Approval for the expanded use of the HPV vaccine was based on data of the vaccine’s use in women.1,3
Unfortunately, adult immunization rates, including among pregnant women, do not equal the higher rates in childhood vaccine uptake, according to Kevin A. Ault, MD, and colleagues. Less than half of women (46.6%) receive influenza vaccination prior to and during pregnancy, for instance.4 Dr. Ault has identified the need for an “immunization champion”—someone who can manage one-on-one conversations with patients in the office setting to enhance the acceptance and uptake of adult and maternal vaccines.
OBG Management:
Dr. Kevin A. Ault, MD: The main thing a practice needs to do is to identify someone who is interested, and this person does not have to be a physician. In fact, he or she can frequently be a member of your nursing staff or office staff. And the word “champion” involves a lot of nuts and bolts: such details as how do you store the vaccine, how do you keep track of it, where are the vaccine information statements filed, where can the provider get more information if there is a question about contraindications? One person should organize all these details. The mechanics of vaccine administration are important as well, as the research shows that the more automated the process is, the better and more smoothly it is carried out. There is certainly a role for “standing orders” for adult vaccines.
OBG Management: What communication approach do you take with patients to enhance vaccination acceptance and uptake?
Dr. Ault: There are multiple research studies that show that provider recommendation is the most important way to get both nonpregnant and pregnant adults to receive vaccinations. Take the pertussis vaccine (the whooping cough booster) as an example. It is a relatively new vaccine recommendation during pregnancy. Your approach is relatively straightforward when explaining it to pregnant women. Make the point that we do not want your newborn to have whooping cough in those first few months of life before the newborn or infant vaccine becomes effective. Most people know they had a whooping cough, or pertussis, vaccine when they were younger, and the concept of the booster is well-known to patients. You should explain that the maternal antibodies pass through the placenta to the fetus, and they provide benefit for the first few months of life after birth.
The pertussis vaccine does not have all the “baggage” of the influenza vaccine. Talking with patients about the flu vaccine may present more challenges. Typically, each fall there is a popular press publication that explains “the 10, or 20, most common myths about influenza vaccine.” Every fall I try to find one of those articles, print it out, and even carry it in my jacket pocket and talk about all the myths. For example, there is a myth that “I always get sick when I get the flu shot.” Obstetricians should be giving patients an inactivated vaccine that does not contain any live flu virus. We should be able to explain to patients, your arm will be sore, and you may have some muscle aches, but you will not have the flu from your flu vaccine.
I think another reason that pregnant women do not always take the flu vaccine is that we do not yet have normalized influenza vaccination in the adult population. Women in their twenties and thirties are generally very healthy and have other concerns when they are pregnant, and they perhaps do not realize that they are more vulnerable to devastating effects of influenza while pregnant. Additionally, maternal influenza vaccination does protect the newborn from flu for the first few months. It is vital that those patients who are due during the dark winter months, when the flu is in season, get vaccinated.
Combat the myths and tell your patients the reasons for flu vaccination. Also tell them that you got your flu shot, like most health care professionals do every fall. You should be prepared to talk about safety. There are wonderful safety data, even some published in 2017 and 2018, about pertussis vaccine safety during pregnancy, and it is very reassuring to patients. For flu, the idea of vaccinating women against influenza has been around for decades, and so we have reliable information about that as well. Certainly, the risks are very minor, and the benefits are potentially huge for the pregnant woman and for the newborn.
OBG Management: When do you recommend that ObGyns administer the flu vaccine for pregnant women?
Dr. Ault: There are 2 issues to this question: when throughout the year and when during the pregnancy to administer the vaccine. First, you want to give the flu vaccine during the usual influenza season during the fall. As soon as the vaccine is available, you will recommend that pregnant women, even in their late pregnancy, get vaccinated so that their newborns who are 3 and 4 months old in the peak flu season are protected. The patients who deliver over the summer, who are coming in for their postpartum visit during the fall, should be getting vaccinated as well, because they are still vulnerable to influenza and pneumonia for several months postpartum.
If you have patients that come in for preconception visits, you could say: “Let’s get this out of the way. You could be pregnant by the time flu season really gets cranked up.”
Because we see patients 10 or 12 times during pregnancy, we certainly have plenty of opportunities to educate patients about and administer the flu vaccine. There are older data that demonstrate if patients do not get the flu vaccine done during early pregnancy, the opportunity may be lost. It is different now because there is more emphasis on vaccinating all adults. Your patients certainly can get their vaccine at the pharmacy or at their primary care doctor; however, delaying until later pregnancy usually means not getting the vaccine.
I would like to address one recent study from Donahue and colleagues that showed a potentially increased risk of miscarriage with flu vaccination.5 That study was an anomaly, as there are many other studies into the issue. Yes, there are not a lot of first trimester data, but there are other studies, including studies by the same authors, that did not find this to be the case.6-10
The 2017 study by Donahue and colleagues was an anomaly because the group of women they were vaccinating were already at high risk for miscarriage. The women were older, had diabetes, or a history of miscarriages. There is selection bias in the study because the pregnant women who were vaccinated were already at higher risk for miscarriage. The Centers for Disease Control and Prevention and the American College of Obstetricians and Gynecologists are not going to change any of their recommendations based on a single study that is different than our previous data.11
Current recommended adult (anyone over 18 years old) immunization schedule
ACOG Immunization Champions (ACOG members who have demonstrated exceptional progress in increasing immunization rates among adults and pregnant women in their communities through leadership, innovation, collaboration, and educational activities aimed at following ACOG and CDC guidance.)
Summary of Maternal Immunization Recommendations is a provider resource from ACOG and the Centers for Disease Control and Prevention.
Maternal Immunization Toolkit contains materials, including the Vaccines During Pregnancy Poster, to support ObGyns on recommending the influenza vaccine and the Tdap vaccine to all pregnant patients.
Influenza Immunization During Pregnancy Toolkit
CDC vaccine schedules app for health care providers
CDC Vaccine Information Statements (available for clinician or patient download)
In October 2018 the US Food and Drug Administration expanded the approved use of the human papillomavirus (HPV) vaccine (Gardasil 9) to adults aged 27 through 45.1 In June 2019, the Centers for Disease Control and Prevention’s Advisory Committee on Immunization Practices (ACIP) voted to extend catch-up HPV vaccination to include all individuals through age 26 and to catch-up HPV vaccination, based on shared clinical decision making, for all adults aged 27 through 45.2 HPV viruses are associated with cervical cancer, as well as several other forms of cancer that affect both women and men. Approval for the expanded use of the HPV vaccine was based on data of the vaccine’s use in women.1,3
Unfortunately, adult immunization rates, including among pregnant women, do not equal the higher rates in childhood vaccine uptake, according to Kevin A. Ault, MD, and colleagues. Less than half of women (46.6%) receive influenza vaccination prior to and during pregnancy, for instance.4 Dr. Ault has identified the need for an “immunization champion”—someone who can manage one-on-one conversations with patients in the office setting to enhance the acceptance and uptake of adult and maternal vaccines.
OBG Management:
Dr. Kevin A. Ault, MD: The main thing a practice needs to do is to identify someone who is interested, and this person does not have to be a physician. In fact, he or she can frequently be a member of your nursing staff or office staff. And the word “champion” involves a lot of nuts and bolts: such details as how do you store the vaccine, how do you keep track of it, where are the vaccine information statements filed, where can the provider get more information if there is a question about contraindications? One person should organize all these details. The mechanics of vaccine administration are important as well, as the research shows that the more automated the process is, the better and more smoothly it is carried out. There is certainly a role for “standing orders” for adult vaccines.
OBG Management: What communication approach do you take with patients to enhance vaccination acceptance and uptake?
Dr. Ault: There are multiple research studies that show that provider recommendation is the most important way to get both nonpregnant and pregnant adults to receive vaccinations. Take the pertussis vaccine (the whooping cough booster) as an example. It is a relatively new vaccine recommendation during pregnancy. Your approach is relatively straightforward when explaining it to pregnant women. Make the point that we do not want your newborn to have whooping cough in those first few months of life before the newborn or infant vaccine becomes effective. Most people know they had a whooping cough, or pertussis, vaccine when they were younger, and the concept of the booster is well-known to patients. You should explain that the maternal antibodies pass through the placenta to the fetus, and they provide benefit for the first few months of life after birth.
The pertussis vaccine does not have all the “baggage” of the influenza vaccine. Talking with patients about the flu vaccine may present more challenges. Typically, each fall there is a popular press publication that explains “the 10, or 20, most common myths about influenza vaccine.” Every fall I try to find one of those articles, print it out, and even carry it in my jacket pocket and talk about all the myths. For example, there is a myth that “I always get sick when I get the flu shot.” Obstetricians should be giving patients an inactivated vaccine that does not contain any live flu virus. We should be able to explain to patients, your arm will be sore, and you may have some muscle aches, but you will not have the flu from your flu vaccine.
I think another reason that pregnant women do not always take the flu vaccine is that we do not yet have normalized influenza vaccination in the adult population. Women in their twenties and thirties are generally very healthy and have other concerns when they are pregnant, and they perhaps do not realize that they are more vulnerable to devastating effects of influenza while pregnant. Additionally, maternal influenza vaccination does protect the newborn from flu for the first few months. It is vital that those patients who are due during the dark winter months, when the flu is in season, get vaccinated.
Combat the myths and tell your patients the reasons for flu vaccination. Also tell them that you got your flu shot, like most health care professionals do every fall. You should be prepared to talk about safety. There are wonderful safety data, even some published in 2017 and 2018, about pertussis vaccine safety during pregnancy, and it is very reassuring to patients. For flu, the idea of vaccinating women against influenza has been around for decades, and so we have reliable information about that as well. Certainly, the risks are very minor, and the benefits are potentially huge for the pregnant woman and for the newborn.
OBG Management: When do you recommend that ObGyns administer the flu vaccine for pregnant women?
Dr. Ault: There are 2 issues to this question: when throughout the year and when during the pregnancy to administer the vaccine. First, you want to give the flu vaccine during the usual influenza season during the fall. As soon as the vaccine is available, you will recommend that pregnant women, even in their late pregnancy, get vaccinated so that their newborns who are 3 and 4 months old in the peak flu season are protected. The patients who deliver over the summer, who are coming in for their postpartum visit during the fall, should be getting vaccinated as well, because they are still vulnerable to influenza and pneumonia for several months postpartum.
If you have patients that come in for preconception visits, you could say: “Let’s get this out of the way. You could be pregnant by the time flu season really gets cranked up.”
Because we see patients 10 or 12 times during pregnancy, we certainly have plenty of opportunities to educate patients about and administer the flu vaccine. There are older data that demonstrate if patients do not get the flu vaccine done during early pregnancy, the opportunity may be lost. It is different now because there is more emphasis on vaccinating all adults. Your patients certainly can get their vaccine at the pharmacy or at their primary care doctor; however, delaying until later pregnancy usually means not getting the vaccine.
I would like to address one recent study from Donahue and colleagues that showed a potentially increased risk of miscarriage with flu vaccination.5 That study was an anomaly, as there are many other studies into the issue. Yes, there are not a lot of first trimester data, but there are other studies, including studies by the same authors, that did not find this to be the case.6-10
The 2017 study by Donahue and colleagues was an anomaly because the group of women they were vaccinating were already at high risk for miscarriage. The women were older, had diabetes, or a history of miscarriages. There is selection bias in the study because the pregnant women who were vaccinated were already at higher risk for miscarriage. The Centers for Disease Control and Prevention and the American College of Obstetricians and Gynecologists are not going to change any of their recommendations based on a single study that is different than our previous data.11
Current recommended adult (anyone over 18 years old) immunization schedule
ACOG Immunization Champions (ACOG members who have demonstrated exceptional progress in increasing immunization rates among adults and pregnant women in their communities through leadership, innovation, collaboration, and educational activities aimed at following ACOG and CDC guidance.)
Summary of Maternal Immunization Recommendations is a provider resource from ACOG and the Centers for Disease Control and Prevention.
Maternal Immunization Toolkit contains materials, including the Vaccines During Pregnancy Poster, to support ObGyns on recommending the influenza vaccine and the Tdap vaccine to all pregnant patients.
Influenza Immunization During Pregnancy Toolkit
CDC vaccine schedules app for health care providers
CDC Vaccine Information Statements (available for clinician or patient download)
- FDA approves expanded use of Gardasil 9 to include individuals 27 through 45 years old [press release]. Washington, DC: Food and Drug Administration; October 5, 2018.
- Color/Blue2. Splete H. ACIP extends HPV vaccine coverage. June 27, 2019. https://www.mdedge.com/obgyn/article/203656/vaccines/acip-extends-hpv-vaccine-coverage. Accessed July 5, 2019.
- Levy BS, Downs Jr L. The HPV vaccine is now recommended for adults aged 27–45: Counseling implications. OBG Manag. 2019;31(1):9-11.
- Frew PM, Randall LA, Malik F, et al. Clinician perspectives on strategies to improve patient maternal immunization acceptability in obstetrics and gynecology practice settings. Hum Vaccin Immunother. 2018;14(7):1548–1557.
- Donahue JG, Kieke BA, King JP, et al. Association of spontaneous abortion with receipt of inactivated influenza vaccine containing H1N1pdm09 in 2010-11 and 2011-12. Vaccine. 2017;35(40):5314-5322.
- Moro PL, Broder K, Zheteyeva Y, et al. Adverse events in pregnant women following administration of trivalent inactivated influenza vaccine and live attenuated influenza vaccine in the Vaccine Adverse Event Reporting System, 1990-2009. Am J Obstet Gynecol. 2011;204:146.e1-146.e7.
- Irving SA, Kieke BA, Donahue JG, et al; Vaccine Safety Datalink. Trivalent inactivated influenza vaccine and spontaneous abortion. 2013;121:159-165.
- Kharbanda EO, Vazquez-Benitez G, Lipkind H, et al; Vaccine Safety Datalink Team. Inactivated influenza vaccine during pregnancy and risks for adverse obstetric events. Obstet Gynecol. 2013;122:659-667.
- Nordin JD, Kharbanda EO, Vazquez-Benitez G, et al; Vaccine Safety Datalink. Maternal Influenza vaccine and risks for preterm or small for gestational age birth. J Pediatrics. 2014;164:1051-1057.e2.
- Kharbanda EO, Vazquez-Benitez G, Romitti PA, et al; Vaccine Safety Datalink. First trimester influenza vaccination and risks for major structural birth defects in offspring. 2017;187:234-239.e4.
- Flu vaccination and possible safety signal. CDC website. https://www.cdc.gov/flu/professionals/vaccination/vaccination-possible-safety-signal.html. Last reviewed September 13, 2017. Accessed May 15, 2019.
- FDA approves expanded use of Gardasil 9 to include individuals 27 through 45 years old [press release]. Washington, DC: Food and Drug Administration; October 5, 2018.
- Color/Blue2. Splete H. ACIP extends HPV vaccine coverage. June 27, 2019. https://www.mdedge.com/obgyn/article/203656/vaccines/acip-extends-hpv-vaccine-coverage. Accessed July 5, 2019.
- Levy BS, Downs Jr L. The HPV vaccine is now recommended for adults aged 27–45: Counseling implications. OBG Manag. 2019;31(1):9-11.
- Frew PM, Randall LA, Malik F, et al. Clinician perspectives on strategies to improve patient maternal immunization acceptability in obstetrics and gynecology practice settings. Hum Vaccin Immunother. 2018;14(7):1548–1557.
- Donahue JG, Kieke BA, King JP, et al. Association of spontaneous abortion with receipt of inactivated influenza vaccine containing H1N1pdm09 in 2010-11 and 2011-12. Vaccine. 2017;35(40):5314-5322.
- Moro PL, Broder K, Zheteyeva Y, et al. Adverse events in pregnant women following administration of trivalent inactivated influenza vaccine and live attenuated influenza vaccine in the Vaccine Adverse Event Reporting System, 1990-2009. Am J Obstet Gynecol. 2011;204:146.e1-146.e7.
- Irving SA, Kieke BA, Donahue JG, et al; Vaccine Safety Datalink. Trivalent inactivated influenza vaccine and spontaneous abortion. 2013;121:159-165.
- Kharbanda EO, Vazquez-Benitez G, Lipkind H, et al; Vaccine Safety Datalink Team. Inactivated influenza vaccine during pregnancy and risks for adverse obstetric events. Obstet Gynecol. 2013;122:659-667.
- Nordin JD, Kharbanda EO, Vazquez-Benitez G, et al; Vaccine Safety Datalink. Maternal Influenza vaccine and risks for preterm or small for gestational age birth. J Pediatrics. 2014;164:1051-1057.e2.
- Kharbanda EO, Vazquez-Benitez G, Romitti PA, et al; Vaccine Safety Datalink. First trimester influenza vaccination and risks for major structural birth defects in offspring. 2017;187:234-239.e4.
- Flu vaccination and possible safety signal. CDC website. https://www.cdc.gov/flu/professionals/vaccination/vaccination-possible-safety-signal.html. Last reviewed September 13, 2017. Accessed May 15, 2019.