Research News

By Susan Wells Courtney and Tom Garry
Reviewed by Dr. Barry A. Hendin, MSAA Chief Medical Officer

COVID-19 Vaccination

As noted in Ask the Doctor, MSAA recommends COVID-19 vaccination in coordination with one’s healthcare provider. While new findings, recommendations, and approvals are ongoing, the facts listed below may give individuals a greater understanding of COVID-19 vaccinations and the research behind them. The majority of this information may be found on the Food and Drug Administration’s (FDA’s) website at Website visitors may click on “COVID-19 Information” to learn about the latest developments. Please note that the information to follow was current at the time of publication.

The Three COVID-19 Vaccines and How They Work

As of September 2021, three vaccines are available for the prevention of coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The Pfizer-BioNTech COVID-19 Vaccine is FDA-approved for individuals 16 years of age and older, and under the FDA-issued emergency use authorization (EUA), the vaccine may also be given to adolescents age 12 through 15. The Moderna COVID-19 Vaccine and Johnson & Johnson’s Janssen COVID-19 Vaccine have both been issued the FDA’s EUA and may be given to individuals 18 years of age and older.

Given in two doses and stored at very cold temperatures, both the Pfizer-BioNTech and Moderna vaccines contain a synthetic piece of mRNA (a genetic material) that instructs cells in the body to make the distinctive “spike” protein of the SARS-CoV-2 virus. When vaccinated, the body produces copies of the spike protein, and the immune system learns to launch an immune response against SARS-CoV-2.

The mRNA in these vaccines is only present in the body for a short time and is not incorporated into, nor does it alter, an individual’s genetic material. Very rare adverse events with the Pfizer-BioNTech and the Moderna Vaccines include myocarditis (inflammation of the heart muscle) and pericarditis (inflammation of the tissue surrounding the heart). Both vaccines are approximately 95% effective in preventing moderate to serious illness five-to-six weeks after the first dose.

Given in one dose and stored at refrigerator temperatures, the Janssen vaccine is more like a flu vaccine and uses a disabled adenovirus to deliver the instructions rather than mRNA. This adenovirus is different from the coronavirus, but is able to deliver instructions on how to protect against the coronavirus.

A serious type of blood clot has been reported as a rare adverse event. The vaccine is approximately 66% effective in preventing moderate to severe illness, and 85% effective in preventing just severe illness, two weeks after the single dose.


Do I need a vaccine if I’ve already had COVID-19?

Available data suggest that previously infected individuals can still be at risk of being reinfected with COVID-19 and could benefit from vaccination.

Does vaccination prevent those from spreading the virus to others?

Most vaccines that protect from viral illnesses also reduce transmission of the virus by those who are vaccinated. While it is hoped this will be the case, this has yet to be proven.

Can the COVID-19 vaccine cause infertility, and is vaccination safe for women who are pregnant or breastfeeding?

No scientific evidence suggests that the vaccine could cause infertility in women and there is no contraindication for pregnant or breastfeeding women to receive the vaccine. Pregnant or breastfeeding women should discuss potential benefits and risks of vaccination with their healthcare provider.

What’s the difference between an additional dose and a booster shot?

According to the Centers for Disease Control and Prevention (CDC) at, sometimes people who are moderately to severely immunocompromised do not build enough protection when they first receive the two-dose vaccination. When this happens, getting another dose of the vaccine can sometimes help them build more protection against the disease. Individuals with MS who are taking certain disease-modifying therapies (DMTs) that suppress or block the immune system may be immunocompromised, and their physician may recommend receiving this additional (third) vaccine.

In contrast, a “booster dose” (or “booster shot”) refers to another dose of a vaccine that is given to someone who has built enough protection after vaccination, but then that protection has decreased over time. This is called “waning immunity.”

Two Experimental Medications for MS Show Encouraging Results

Findings from a Phase II study of the investigational medication tolebrutinib support conducting Phase III trials to further evaluate its efficacy and safety in people with relapsing-remitting multiple sclerosis (RRMS). Tolebrutinib inhibits Bruton’s tyrosine kinase, or BTK. BTK is an enzyme expressed in B cells and myeloid cells, which are components of the body’s innate immune system, and in microglia, which are innate immune cells in the central nervous system. B cells, myeloid cells, and microglia all are believed to play a role in the inflammation seen in MS.

The Phase II study involved 130 people ages 18 to 55 years who had been diagnosed with RRMS. The research examined how four different doses of tolebrutinib affected the number of new gadolinium-enhancing lesions seen on magnetic resonance imaging (MRI) after 12 weeks of treatment with the oral medication. The investigators found a dose-dependent reduction in the number of new lesions seen per patient.

Taken by infusion every six months, 1,000 people with relapsing forms of MS (RMS) participated in two studies with the investigational medication ublituximab. Researchers found that the annualized relapse rates (ARRs) were 50% to 60% lower than those of study subjects taking the disease-modifying therapy Aubagio® (teriflunomide). Like Ocrevus™ (ocrelizumab), Rituxan® (rituximab), and Kesimpta® (ofatumumab), ublituximab targets the CD20 molecule to deplete B cells. 

For More Information
For general information or to speak with a trained Client Services Specialist, please call MSAA’s Helpline at (800) 532-7667, extension 154. Helpline hours are Monday through Thursday, 8:30 AM to 8:00 PM, Eastern Time; and Friday 8:30 AM to 5:00 PM Eastern Time. Questions to MSAA’s Client Services department may also be emailed to

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