COVID-19 Vaccines, Additional Shots, and Boosters: FAQ

Below are answers to some of the frequently asked questions we’ve received recently regarding COVID-19 vaccines, additional shots and boosters. In addition, here is a link to our prior Myths and Facts about Vaccines document for your reference which has basic information about the safety and efficacy of the COVID-19 vaccinations.

>> After reading the FAQ below, please also see "Vaccines and Booster Guidance for MS Patients on Disease Modifying Therapies" for recommendations directly from the MS Center Neurology Team on which shots to get and when to get them.  

What MS disease modifying therapies might lower vaccine responsiveness?

Several classes of MS disease modifying therapies (DMTs) suppress or compromise the immune system function substantially, which can result in an increase in infections, and development of some cancers or even other autoimmune disorders. Some also have been proven to (or likely do) have an impact on suppressing parts of the normal immune system reaction to vaccines, including the anti-CD20 drugs (Rituxan, Ocrevus and Kesimpta), the S1P modulators (Gilenya and its generics, Mayzent, Zeposia, and Ponvory), Lemtrada, Mavenclad, and any chemotherapy drugs. To maximize vaccine response, this might suggest use of additional doses of the vaccine.

What is the difference between an additional third dose and a booster?

An additional dose is intended to improve the response to the first and second dose of the vaccine in immunocompromised people. A booster is given when the immune response to the first, second dose, and any additional dose is likely to have decreased over time.

People who are immunocompromised who received the Pfizer or Moderna vaccine may receive a total of four COVID-19 vaccine doses (the first two doses, an additional dose, and a booster).

The additional third dose of the Moderna vaccine is a full dose, the booster of the Moderna vaccine is a half dose. Pfizer doses are all the same strength.

Should I get an additional dose and booster?

Yes. If you are on an immunosuppressing disease modifying therapy, it is very important to get BOTH an additional vaccine dose and a booster shot to increase the development of antibodies. It is particularly important if you are on anti-CD20 drugs (Ocrevus, Rituxan, and Kesimpta) and S1P drugs (Gilenya, Mayzent, Zeposia, and Ponvory), Lemtrada, Mavenclad, or any chemotherapy drugs. Please click here for more specific current guidance and timing recommendations.

If I have finished the 2-shot series and a booster, do I now need an additional dose? When should that happen?

We would call that booster you received the additional dose and would still recommend a booster. Please see the chart for guidance on the timing of the additional and booster doses. The initial doses help mount an immune response, and the later doses help increase and/or sustain those immune responses.

I’m on a disease modifying drug, how many doses of the COVID-19 vaccine should I take to be fully vaccinated?

Please refer to the charts here for our recommendations.

Can I get multiple vaccines, such as for COVID and the flu, at one time?

Yes, but it is recommended that you spread them out if possible. Most commonly, this just means getting one vaccine, and then once it is clear you have done well (usually within a couple of days), get the other. In case you have a reaction it will be easier to know which vaccine caused the reaction. This can also help tolerate them better.

How do I know if I’ve mounted antibodies?

Protection from a vaccine includes a response from T cells in addition to the ability to mount antibodies to an infection/vaccine. Antibodies can develop to different viral proteins. During a COVID infection, antibodies will form to a number of proteins for the virus including the spike protein and nucleocapsid proteins. With vaccination, antibodies are mounted against only the spike protein. The antibodies that we consider protective are those against the spike protein. The spike protein is on the outside of the virus and by binding to this protein, the virus cannot bind and attack our cells. The challenge remains knowing how much antibody is required to provide this protection, but better tests are now available in research settings. One reason we and the CDC have been hesitant to recommend testing is not knowing how that would change things functionally for the patient. This is especially true because an important and separate part of the immune system reaction to the vaccine that can provide significant protection, the T Cell response, is not measured by these tests. These T Cell response tests are expensive and challenging to do and are not available commercially.

What if I got my vaccines before starting an anti-CD20 therapy (Ocrevus, Rituximab, Kesimpta)?

If you got your vaccines 4 weeks before starting treatment, you likely mounted a normal immune response as most people do to the COVID vaccines.

If I’ve had COVID, how long should I wait to get a booster?

The general recommendation is to wait four weeks after COVID infection to get any of the COVID vaccine doses.

If I’ve had COVID, and also full vaccination, do I need a booster or additional dose?

The answer is not perfectly known, but we recommend getting the additional and/or booster doses as if not having had COVID.

If I get COVID-19, what should I do?

If you are a patient at UCHealth, please send a note through My Health Connection to let your care team know that you have COVID and how you’re doing. It is important to seek medical help if you are having any significant symptoms, especially trouble breathing. If you have a fever, try Tylenol first. It is important to isolate at home if symptoms are not severe and stay home for as long as you are not feeling well. Follow Current CDC and local guidelines.

Do you recommend one vaccine over another?

It is most important to get fully vaccinated as soon as possible. All three vaccines approved for use in the United States are proven to be safe and effective. If you have the choice, we encourage individuals to get either the Pfizer/Biontech or the Moderna vaccines. Data shows the mRNA vaccines are more effective than the Johnson & Johnson vaccine. Additionally, the Johnson & Johnson vaccine has a small risk of blood clots, which the others do not.

What are the current COVID-19 treatment options and are they available?

Treatment options have been slowly developed and much more data will be needed to assess efficacy. Several treatment options have recently received Emergency Use Authorization, but most of them are not currently available.

Veklury (Remdesivir): Received Emergency Use Authorization from the FDA several months ago and is being used a fair amount for hospitalized COVID-19 patients with symptomatic COVID. The FDA announced on January 21 that Veklury is now approved for treating COVID patients in an outpatient setting for individuals 12 and up (who weigh 40 kg or more) with mild to moderate COVID-19 who are at high risk of progressing to severe COVID-19.

Monoclonal antibodies: This is a group of therapies that received Emergency Use Authorization for non-hospitalized patients. They could be used as a treatment after infection, or as a prophylactic for those not yet infected. The earlier approved therapies have not shown effectiveness against Omicron and the newer therapies that have shown effectiveness against Omicron are not widely available. There is no concern about getting these treatments while on MS DMTs.

Evusheld: One specific monoclonal antibody treatment recently approved at the end of 2021 as a prophylactic therapy for moderately to severely immunosuppressed patients who have been vaccinated but not developed protective antibodies. This has efficacy against the Omicron variant. However, this treatment remains in limited supply, and at present is only available at UCHealth to bone marrow and solid organ transplant patients. There could be different degrees of availability at other hospitals, but we do not know this. Those on anti-CD20 drugs will be next on the list at UCH.

Paxlovid: An anti-viral medication which received Emergency Use Authorization on December 21, 2021. Preliminary data showed no deaths in those treated with Paxlovid vs 10 deaths in the placebo group. This treatment has very limited availability at this time.

We will keep you apprised of any changes to availability to these treatment options.