COVID-19 VACCINES AND MS

COVID-19 Vaccines and MS Will a Covid-19 vaccine be safe for people with MS?

Having MS does not mean you should not take a vaccine. However, some of the disease modifying therapies (DMTs) that are used to treat MS can make some vaccines unsafe or less effective, these are live vaccines. At the moment, the vaccines for COVID-19 are inactivated meaning they are not live. There should be no risk to people living with MS taking these vaccines, regardless of what DMT they are on. Should a live vaccine for COVID-19 become available, you should speak to your healthcare team for individualised information.

Will a vaccine be effective for people living with MS?

Some of the DMTs used to treat MS work by suppressing the immune system to a point where a vaccine may not be as effective.

Ocrelizumab (Ocrevus) and Fingolimod (Gilenya)

Ocrevus works by depleting B cells. B cells produce antibodies which provide immunity against vaccines. Those receiving Ocrevus have a reduced ability to respond to vaccines at all times. For this reason, it is thought that being on this treatment may mean that a COVID-19 vaccine will not be as effective as it could be. It may reduce the response to some vaccines by up to 50%.

For those just starting this treatment, it may be beneficial to delay the first dose in order to receive the vaccine first.

For those already on this treatment, delaying further infusions would have a limited benefit for increasing the effectiveness of a vaccine.

It would still be advisable to receive a COVID-19 vaccine.

Advice for those on Rituximab would be similar.

There may also be a reduced response for those taking Fingolimod (Gilenya). It would not be advisable to stop treatment in order to increase immune response to the vaccine.

Alemtuzumab (Lemtrada) and Cladribine (Mavenclad)

Recent treatment with Alemtuzumab (Lemtrada) may reduce response to a vaccine. It is recommended that those who receive this treatment wait 3 months after their treatment to receive a vaccination.

There may be a reduced response to a vaccine with Cladribine (Mavenclad) and it may be advisable to wait 3 months after a course before receiving a vaccine.

Please note: Second courses of Lemtrada or Mavenclad can safely be delayed for several months without concerns for a return of disease activity. This will allow some flexibility to schedule vaccination in advance.

Delays to start treatment

If starting for the first time on any of the above treatments (Ocrevus, Gilenya, Lemtrada and Mavenclad) you should discuss with your team whether it might be preferable to wait until you have been vaccinated. The risks of this strategy will depend on your individual case and on the availability of the vaccine.

Other Treatments for Multiple Sclerosis (Copaxone, Aubagio, Tecfidera, Avonex, Extavia, Plegridy, Rebif, Tysabri)

There is no reason to believe other treatments will reduce the efficacy of vaccines. This covers: glatiramer acetate (Copaxone), teriflunomide (Aubagio) , dimethyl fumarate (Tecfidera), beta interferons (Avonex, Betaferon, Extavia, Plegridy, Rebif), and natalizumab (Tysabri).

Haematopoietic stem cell transplantation (HSCT)

You should wait at least 6 moths after treatment before getting vaccinated as HSCT will likely reduce response to the vaccine.

Other important points

The current vaccines require 2 doses and for some treatments (for example Ocrevus, Mavenclad, or Lemtrada) your MS team may advise you on specific timing in relation to this. For example, it may  be advisable to wait until after your second dose of vaccine before a further course of DMT – or to resume treatment after a single dose of vaccine (delaying the second).  

You should leave at least a 7-day gap between getting the flu vaccine and a COVID-19 vaccination.

How will a COVID-19 vaccine be of benefit to people living with MS?

If people living with MS receive a vaccine that is effective for them, they will have direct immunity against COVID-19.

If they are on a medication which means a vaccine may not be effective for them, there will still be a reduced risk of exposure as a vaccine being made widely available will help to control the pandemic. As the number of people vaccinated against COVID-19 rises, the number of people who can be infected by it will reduce. This will decrease the risk of exposure to COVID-19, benefitting everyone.

Could taking a vaccine cause a relapse or worsen MS?

There is always a small risk of a vaccination triggering an immune response but this is overwhelmingly in relation to live vaccines. The vaccines that we currently have access to are not live, this risk is greatly reduced to a point that it is not concerning.

Will children with MS be offered the vaccine?

Children with MS wouldn’t be at high risk of severe COVID-19 disease. In the prioritisation list for the COVID-19 vaccine, there is no provision for earlier access to the vaccine for children living with MS. They will receive the vaccine at the same time as other children.

Have these vaccines been developed too quickly to be deemed safe?

While it normally takes about 10 years for a vaccine to come to market, there are a number of reasons why the timeline for the COVID-19 vaccines has been shortened. Enormous investment and scientific and medical research have gone into the development of these vaccines. This has happened on a scale never previously seen in vaccine development. The sample size, or number of people in the COVID-19 vaccine trials were much larger than normal. This helped researchers to quickly detect side-effects or adverse events related to these vaccines.

The high number of COVID-19 cases across the world also allowed researchers to quickly measure the differences in disease risk between those who received the vaccine and those who were given the placebo vaccine. Developers and regulators have been working together earlier in the process than they normally would.

This meant that regulators were kept aware of developments allowing the authorisation process to move along as quickly as possible. None of these measures imply that short-cuts have been taken or that the integrity of the safety, science or ethics around these vaccines has been compromised.

What about people who are worried about side effects of vaccines?

Naturally, some people will be concerned about side-effects of a vaccine, particularly as it made headlines when one of the trials temporarily paused due to side effects. It is common that vaccine trials would pause if there is any concern, though it wouldn’t always make the evening news! This pause allows researchers to consider what has been observed and to restart if it appears to be safe. The trial did continue as it was deemed safe to do so


Information on the various vaccines being administered in Ireland is available from the HSE website: https://www2.hse.ie/screening-and-vaccinations/covid-19-vaccine/

Some people living with MS have received a dose of the AstraZeneca vaccine. Information on the second dose of this vaccine can be found  by clicking here

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