Two of the COVID-19 vaccines currently authorized for emergency use by the U.S. Food and Drug Administration require two doses to reach the full level of protection. But what happens if a woman finds out she’s pregnant after receiving the first dose of the vaccine? Should she get the second dose? Johns Hopkins Medicine experts say yes.

“At this time, there’s no evidence that the COVID-19 vaccine increases risks for unborn babies in the first trimester, so if a woman gets the first dose of the vaccine around the time she gets pregnant, it’s recommended that she go ahead and get the second shot,” says Jeanne Sheffield, M.D., director of maternal-fetal medicine and professor of gynecology and obstetrics at the Johns Hopkins University School of Medicine.

Research studies have shown that women who are pregnant and develop COVID-19 are at an increased risk for severe illness, complications and death compared to non-pregnant women. Moreover, many pregnant women have medical conditions that may further increase the danger.

“Women should talk with their doctor to discuss all factors about the vaccine and their pregnancy,” says Sheffield.

Getting a COVID-19 vaccine may come with mild to moderate side effects. The vast majority of these side effects, Sheffield says, are very similar to those among women who are not pregnant and may include pain at the injection site, low-grade fever, chills, muscle aches, headaches or a combination of these symptoms. Side effects mostly occur after the second dose, and usually disappear within a few days.

Pregnant women may experience changes in their immune systems that can make them more vulnerable to respiratory viruses, such as SARS-CoV-2 which causes COVID-19. This, says Sheffield, means expectant mothers should be proactive regarding safety measures.

“If you’re pregnant, you should take precautions to protect yourself from getting COVID-19, including physical distancing, wearing a mask, hand-washing and staying in close communication with your health care provider — even after vaccination,” she says.

Sheffield adds that it’s important to understand that the initial COVID-19 vaccine clinical trials did not evaluate their effectiveness and safety for pregnant women. However, she says preliminary developmental and reproductive toxicity studies do not indicate any adverse effects on reproduction or fetal development. She says more data from additional studies will be available in the coming months that should better address these issues.

While there are still many unanswered questions about the COVID-19 vaccines for pregnant women, Johns Hopkins Medicine agrees with and supports the recommendations of the U.S. Centers for Disease Control and Prevention’s Advisory Committee on Immunization Practices, the American College of Obstetricians and Gynecologists and the Society for Maternal-Fetal Medicine.

“We know that SARS-CoV-2 adversely affects pregnant women and that is one of the main reasons why we’re supportive of vaccinating them against COVID-19,” says Sheffield.

Sheffield is available for interviews.



A new study by Johns Hopkins Medicine researchers provides evidence that CD4+ T lymphocytes — immune system cells also known as helper T cells — produced by people who have received either of the two messenger RNA (mRNA) vaccines for COVID-19 caused by the original SARS-CoV-2 strain also will recognize the mutant variants of the coronavirus that are rapidly becoming the dominant types worldwide.

The researchers say this suggests that T cell responses elicited or enhanced by the vaccines should be able to control the current SARS-CoV-2 variants without needing to be updated or modified. They also found that the same T cells may provide some protection from another member of the coronavirus family that is responsible for one type of the common cold.

The findings were reported April 6, 2021, in the Journal of Clinical Investigation.

CD4+ T cells get their “helper” nickname because they assist another type of immune cell, the B lymphocyte (B cell), in responding to surface proteins — antigens — on cells infected by invaders that include viruses such as SARS-CoV-2. Activated by the CD4+ T cells, immature B cells become either plasma cells that produce antibodies to mark infected cells for disposal from the body or memory cells that “remember” the antigen’s biochemistry for a faster response to future infections.

In the case of SARS-CoV-2, the antigen is the protein making up the spikes that protrude from the surface of the virus. The mRNA vaccines — known by their manufacturer’s names, Pfizer-BioNTech and Moderna — provide genetic instructions to a vaccinated person’s immune system to recognize the spike protein and start  production of antibodies against SARS-CoV-2.

CD4+ T cells also send out chemical messengers that attract another type of T cell — known as the CD8+ T cell (or “killer T cell”) — so that the virus-infected cells can be removed.

To conduct their helper T cell study, the researchers evaluated blood samples from 30 healthy health care workers and laboratory donors who had not previously tested positive for SARS-CoV-2 — both before and after two doses of a COVID-19 mRNA vaccine. The participants, 12 women and 18 men, ranged in age from 20 to 59.

CD4+ T cells extracted from the blood samples were analyzed for their responses to various components (protein fragments known as peptides) from the original strain SARS-CoV-2 spike protein and three common cold coronaviruses.

The researchers discovered that vaccine recipients — as expected — had broad T cell responses to the original strain SARS-CoV-2 spike peptides.

“We identified 23 distinct T cell-targeted peptides, of which only four appear affected by the mutations that created the variant coronaviruses first seen in the United Kingdom and South Africa,” says study senior author Joel Blankson, M.D., Ph.D., professor of medicine at the Johns Hopkins University School of Medicine. “That means the other 19 peptides are the same in the original SARS-CoV-2 and the newer strains, so the mRNA vaccines should induce T cells that respond well to the variants.”

Blankson says this is important because previous studies showed that antibodies don’t recognize the SARS-CoV-2 variants as well as the CD4+ T cells.

“So the T cells may help prevent the variant viruses from causing severe COVID-19 disease even if antibodies don’t stop them from infecting a person,” he explains.

When the researchers looked at the vaccine-induced T cell response to the spike proteins of three common cold coronaviruses, they saw a three-fold increase for one, HCoV-NL63, but not the other two.

“Further studies are needed to determine why this occurred,” says Blankson. “We suspect that HCoV-NL63 may have more epitopes [peptides that elicit an immune response] in common with SARS-CoV-2 than the other common cold coronaviruses.”

In a recent and related study, Blankson and Johns Hopkins Medicine colleagues looked at blood from convalescent patients who had recovered from a SARS-CoV-2 infection and identified the unique receptors on memory CD4+ T cell that recognize the spike proteins of both the original strain of SARS-CoV-2 and four common cold coronaviruses.

Blankson says that characterizing these T cell receptors may be helpful in guiding  development of future vaccines for a variety of coronaviruses.

Blankson is available for interviews.



The Johns Hopkins Disability Health Research Center has updated the COVID-19 Vaccine Prioritization Dashboard, a tool to help people with disabilities get vaccinated and arm advocates and policymakers with data to improve the disability community’s inclusion in the vaccination effort.

The tool will now include accessible data visualizations to expand on the recently launched effort to help people with disabilities determine when they qualify for the COVID-19 vaccine. The visualizations also show how different states prioritize the disability community in the vaccine rollout.

One of the many barriers to vaccination for people with disabilities is the lack of accessibility to information. Often state websites rely on charts and tables to present information, making it difficult or impossible for people with vision impairments and other disabilities to comprehend or use.

The dashboard will now track the accessibility of state and U.S. territory COVID-19 vaccine information and registration websites, and will update that information weekly. Currently according to the tool, the five states with the most accessible sites for vaccine information are Minnesota, Maryland, Kansas, Louisiana and California. The most accessible states for vaccine registration are Nevada, California, Massachusetts, Indiana and Virginia.

Bonnielin Swenor, Ph.D., M.P.H., director of the Johns Hopkins Disability Health Research Center and associate professor of ophthalmology at the Johns Hopkins University School of Medicine, leads the dashboard project.

“Since we began tracking COVID-19 vaccine website accessibility just a few weeks ago, there have been improvements, but many issues remain,” says Swenor. “The majority of U.S. state and territory COVID-19 vaccine websites have over 100 accessibility errors, which is an error rate that is sure to prevent many people with disabilities from accessing the vaccine.”

The work is supported by the American Association of People with Disabilities. Collaborators include the Center for Dignity in Healthcare for People with Disabilities — a national coalition of medical care providers, researchers, ethicists, and people with disabilities and their family members — and WebAIM, a nonprofit group at Utah State University that empowers individuals and organizations to create web content that is accessible to the disability community.

Swenor is available for interviews.