Vaxxing for flu? One week’s as good as two

3 minute read


A new trial in A&R gives a more feasible pathway for methotrexate around vaccinations.


Data from a study looking at MTX withholding in RA patients after influenza vaccination shows that one week is long enough.

Amid the current severe flu season, with troublingly low vaccination rates in the general population, there’s reassuring data for rheumatoid arthritis patients taking methotrexate.

After previously demonstrating that withholding MTX for two or four weeks after a flu vaccine improves humoral response, South Korean researchers published study findings  showing that the MTX holiday could be cut to one week without compromising humoral response.

The study found that at four weeks post vaccination, antibody titre levels don’t appear to differ in rheumatoid arthritis patients who wait only one week to restart MTX after their flu vaccine compared to those who wait for two.

Now, in a letter published in Arthritis & Rheumatology, the researchers have provided data from the 16-week post-vaccination follow-up study. It was also presented at ACR Convergence 2022.

In the prospective randomised parallel-group multi-centre non-inferiority trial, RA patients on a stable dose of MTX were randomly assigned to hold MTX for one week or two weeks after receiving the quadrivalent 2021–2022 seasonal influenza vaccine, with around 90 patients in each group. A control group of 62 people without autoimmune disease was included as a reference. 

The primary outcome was satisfactory vaccine response, defined as at least four-fold increase in antibody titres against two or more of the vaccine strains four weeks after vaccination. Secondary outcomes include positive response and antibody titres at four and 16 weeks after vaccination.  

The proportion of patients with a satisfactory vaccine response was similar in the one-week and two-week groups at week four and week 16. Around 70% in both groups had a satisfactory response at four weeks, and almost 80% in both groups at 16 weeks.

There was no difference in change in disease activity score between the two groups at either time point, nor in flare rates. The vaccine was well tolerated.

“This study showed clearly that skipping MTX for 1 week is just as effective as skipping it for 2 weeks in producing a sustained (i.e. for up to 16 weeks after vaccination) satisfactory vaccine response to seasonal influenza vaccination in patients with RA taking a stable dose of MTX without worsening disease activity,” concluded the authors.

“Therefore, patients should skip MTX for 1 or 2 weeks after vaccination.

“This simple and safe vaccination strategy can be easily implemented in routine clinical practice and help ensure adequate vaccination coverage in clinical practice without uncertainty about the safety and efficacy of vaccines in this patient population.”

Arthritis & Rheumatology 2023, online 6 July

End of content

No more pages to load

Log In Register ×