Most Pregnant Women With HIV Don't Get Recommended Vaccinations

Fewer than one-third of women with HIV who were pregnant got recommended routine vaccinations, according to a multicenter cohort study.

Among 310 pregnancies in women living with HIV, the tetanus toxoid, reduced diphtheria toxoid, and acellular pertussis (Tdap) vaccine was administered to 32.6%, influenza vaccine to 31.6%, and both vaccines to 22.6%, Saba Berhie, MD, of Brigham and Women's Hospital in Boston, and colleagues reported in JAMA Network Open.

The authors characterized these rates as low. "Identifying and addressing barriers to vaccination receipt is urgently needed for pregnant people with HIV," they wrote.

The CDC recommends all women receive Tdap during week 27-36 of each pregnancy, preferably earlier during this window. Because women who are pregnant and their infants are at increased risk for influenza-related illness and death, the CDC recommends the influenza vaccine for all pregnant persons. The flu vaccine can be given during any trimester of pregnancy but should be a flu shot rather than a live attenuated influenza vaccine (LAIV, or nasal spray).

Adherence to those recommendations is suboptimal overall, even in women without HIV. According to recent data from the CDC, about 47% of women received influenza vaccination before or during pregnancy, and about 55% of women with a recent live birth received Tdap vaccination during pregnancy. In that study, there was a substantial increase in vaccine uptake among women whose provider recommended vaccination.

"Counseling about and receiving antenatal vaccinations are of utmost importance for all pregnant people, especially those with immunocompromising comorbidities like HIV," Berhie and colleagues wrote.

Some data suggest that people living with HIV have a poorer immune response to vaccination than those without the disease, the authors noted, while emphasizing that "no risks have been revealed and vaccination continues to be the standard of care in this population."

Consistent with prior studies, the researchers found that prior pregnancy impacted vaccination rates. Receipt of the flu vaccine was lower among multiparous women with HIV versus those who had never given birth (adjusted risk ratio [aRR] 0.57, 95% CI 0.39-0.83, P=0.004), while the relationship was less pronounced for Tdap.

Also, pregnancies of multiparous individuals with HIV were associated with a nonsignificant trend for lower likelihood of receiving both the Tdap and influenza vaccines (aRR 0.59, 95% CI 0.35-1.00, P=0.05).

Overall, vaccination during pregnancy was less frequent in participants who were younger, multiparous, had low income, or had perinatally acquired HIV, but these differences did not reach statistical significance.

The Surveillance Monitoring for ART Toxicities (SMARTT) study is an ongoing study evaluating safety of antiretroviral treatment in pregnancy and early childhood. The Women's Health Study (WHS) was a nested substudy of SMARTT that evaluated the health of pregnant and nonpregnant women with HIV. Berhie's analysis included a total of 278 women with 310 pregnancies with vaccination data available between December 2017 and July 2019.

When compared to women in the WHS that were excluded from this analysis due to missing vaccination data, included women were more likely to be high school graduates (79% vs 70%) and nulliparous (28% vs 17%). They were also more likely to have acquired HIV perinatally (21% vs 12%) and less likely to have comorbidities (27% vs 33%).

Of the women included in the final analysis, 77% identified as Black and 25% as Hispanic. Mean age at conception was 29.5 years. Most women (69%) had initiated prenatal care by the end of the first trimester of pregnancy.

The authors pointed out that reasons why pregnant women with HIV did not get vaccinated was not determined in this study. However, inadequate clinician recommendation for vaccination, vaccine hesitancy or refusal, and barriers to healthcare access might have contributed to the poor vaccine uptake.

Even though participants were enrolled prospectively, medical record data was reviewed retrospectively and may have underestimated vaccination rates. On the other hand, the study population might have been more engaged with the healthcare system and potentially have higher vaccination rates than the HIV community as a whole, the authors conjectured.

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