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Q&A: Helping Carry the Vaccination Decision-Making Burden during Pregnancy

With limited data on the efficacy and safety of vaccines in pregnant people due to antiquated policies, this population is either unfairly blocked from receiving vaccinations or forced to decide to get vaccinated without clear public health guidance. The COVID-19 pandemic has been an opportunity to prioritize pregnant people, but there is yet again a lack of data on COVID-19 vaccination and pregnancy.

Joshua E. Porterfield, PhD
August 25, 2021

Pregnant people have historically been excluded from clinical trials of new vaccines and in initial vaccine deployment, even when diseases are known to disproportionately impact them. Dr. Chizoba Wonodi, a member of the team behind the COVID-19 Maternal Immunization Tracker (COMIT), believes that we should include pregnant people in more studies and collect better data on vaccinations overall to push for improved vaccine coverage worldwide.

What are some of the challenges in regard to vaccination data and pregnancy?

Vaccine manufacturers have typically excluded pregnant people from vaccine clinical trials. As a result, there is scant data to ascertain whether new vaccines are safe and effective during pregnancy. In the absence of such data, public health authorities are hesitant to make clear recommendations for pregnant people. This puts the decision-making burden on pregnant people and their doctors, even though they also must contend with the lack of data. Sometimes, pregnant people are even prohibited from receiving vaccines in a bid to protect their fetus from a theoretical risk of harm from the vaccine since there is no data proving otherwise.

“It's unfair and unjust for pregnant people to be caught up in this vicious cycle of exclusion from clinical trials, the resulting dearth of data, and denial of access to vaccination exposing them to risk from preventable diseases.”

We know that pregnant people have increased risks of developing COVID-19, which is why it was critical to develop a vaccine that is safe and effective for this population. However, pregnant people were still excluded from the first set of COVID-19 vaccine clinical trials initiated in 2020. The FDA actually encouraged developers to consider the inclusion of pregnant people in pre-licensure COVID-19 vaccine trials. Despite that, none were enrolled for any of the pivotal trials. This lack of data and inclusion is concerning.

We already have guidelines developed to address the inequities in vaccination data and deployment with pregnant people. The PREVENT guidance was developed by a team at Johns Hopkins led by Drs. Ruth Fadden, Ruth Karon, and Carleigh Krubiner, involving an international group of collaborators across multiple fields. They came together to identify 22 actions to shift the paradigm around pregnancy and vaccination. The team produced a roadmap for us to ethically, responsibly, and respectfully include the interest of pregnant people in the development and deployment of vaccines against emerging pathogens. These guidelines need to be considered and adopted.

Can you describe the data collection efforts of the COMIT project?

Our aim is to identify, collect, and present publicly available country and global-level policies or positions on COVID-19 vaccination in pregnancy and lactation. These recommendations come from regulatory authorities, public health authorities, and even professional associations, like associations of obstetricians and gynecologists. We exclusively use publicly available data from a variety of sources. When we find multiple sources for a given country, we give priority to the public health agency of the country, as it is the official position.

After obtaining these data through a systematic keyword search on Google for all countries or from pre-identified websites, we classify each country’s positions based on permissiveness, and identify countries with no official position or a contradictory one. Within COMIT you can filter by vaccine product to see the recommendations by country and by pregnancy or lactation. Every two weeks, an online sweep of the data is done to see if the recommendations have changed because the situation is dynamic.

What have you learned with this data on global COVID-19 vaccination policies in pregnancy?

Almost every country’s policy mentioned the constraint of the lack of data, which is a handicap to regulatory and public health agencies in developing firm recommendations. We also noticed variability in the interpretations and the recommendations across countries, given they were all making decisions based on the same, very limited data. On the COMIT website we list 28 countries whose position is on the permissive end of the spectrum — Recommended for Some or All, and 33 countries on the opposite end of the spectrum — Not Recommended. If you are a pregnant woman and you saw this range of positions on the COVID-19 vaccine and pregnancy, what would you make of it? What if you are a policy maker, how would you assess your country’s stance on vaccinating pregnant people?

“There is a limited amount of vaccine trial data. Every country is using the same set of information to make their decisions, yet they are arriving at different conclusions.”

As far as I know, COMIT is the only source that aggregates countries’ policy positions on COVID-19 vaccination in pregnancy. We hope that when policy makers from countries with more restrictive positions come to the site and see that many other countries recommend vaccination for pregnant people because the benefits outweigh the risks, they will reconsider their positions and make clear recommendations for pregnant people in their countries to be vaccinated.

How do we collect data on pregnant people that are able to get vaccinated?

The CDC has set up data systems to monitor vaccinated individuals for adverse events in the United States. The Vaccine Adverse Event Reporting System (VAERS) and the v-safe COVID-19 Vaccine Pregnancy Registry are used to monitor the safety of COVID-19 vaccination in pregnant people. Vaccine Safety Datalink (VSD) monitors and evaluates the safety of vaccines and assesses if side effects captured in VAERS can be attributed to vaccination. One of the key findings from these systems is that there is no elevated risk of adverse birth outcomes among pregnant people who have taken the vaccine.

Lower- and middle-income countries (LMICs) also have existing pharmacovigilance and surveillance systems for adverse events following immunizations. These systems are being modified to track adverse outcomes of COVID-19 vaccination. Some countries do not have a specific system for pregnant people, though they will be captured in the general system if they receive vaccines. Without an intentional plan to analyze vaccinated pregnant people as a distinct subpopulation, the information from these general surveillance systems may be insufficient to produce sound results and valid interpretations for this subpopulation.

How can we improve vaccine data collection for all people globally?

The COVID-19 pandemic is an opportunity for countries that don't have immunization registries to put them in place, particularly now that technology can really enable some of the democratization of these registries. It doesn’t make sense to copy systems that worked in developed countries because there might be systematic barriers and constraints that will make it difficult to operate those systems in LMICs. That complexity has to be envisioned, worked out, and then tailored for the context, but that’s no excuse not to act.

Before COVID-19, global coverage of childhood vaccination stagnated at 85% for 10 years. Now there is a renewed focus on reaching those last unvaccinated children. It's going to take new ideas, data, and partnerships for us to achieve higher coverage and equity of vaccination. Additional data systems need to come into play for us to be better informed about our strategies to improve immunization coverage globally, nationally, and particularly locally. We need to listen to communities and adopt a human-centered approach in developing hyper-local solutions for improving vaccination coverage.

“It should be a decade of data for vaccines, where data emanates from the smallest level to make decisions, aggregating upwards.”

Joshua E. Porterfield, PhD

Dr. Joshua E. Porterfield, Pandemic Data Initiative content lead, is a writer with the Centers for Civic Impact. He is using his PhD in Chemical and Biomolecular Engineering to give an informed perspective on public health data issues.