Indian Journal of Sexually Transmitted Diseases and AIDS
: 2022  |  Volume : 43  |  Issue : 2  |  Page : 218--219

Venereal disease research laboratory serology after COVID-19 vaccination: The first report

Sora Yasri1, Viroj Wiwanitkit2,  
1 KM Primary Center, Bangkok, Thailand
2 Department of Community Medicine, Dr. D. Y. Patil University, Pune, Maharashtra, India

Correspondence Address:
Dr. Sora Yasri
KM Primary Center, Bangkok

How to cite this article:
Yasri S, Wiwanitkit V. Venereal disease research laboratory serology after COVID-19 vaccination: The first report.Indian J Sex Transm Dis 2022;43:218-219

How to cite this URL:
Yasri S, Wiwanitkit V. Venereal disease research laboratory serology after COVID-19 vaccination: The first report. Indian J Sex Transm Dis [serial online] 2022 [cited 2023 Sep 22 ];43:218-219
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COVID-19 is still an important health problem. At present, COVID-19 vaccination is recommended and accepted as the best preventive measure against COVID-19. The effect of vaccination is an interesting issue in clinical medicine. As a new vaccine, knowledge is still limited. Here, the authors would like to share data on venereal disease research laboratory (VDRL) serology after COVID-19 vaccination: The first report. The patient is a 35-year-old female diagnosed with syphilis and received complete course of penicillin therapy. VDRL serology data on this case are presented in [Table 1]. Based on this data, it might show that the vaccine might have effect of VDRL serology. A false-positive VDRL might occur. However, since this is only an observation in a single case and considered a preliminary report, further studies for getting more data are required for the final conclusion. The impact of COVID-19 on epidemiology of syphilis is sporadically reported,[1],[2] but the impact of COVID-19 vaccination has never been mentioned in any literature. In fact, false-positive VDRL is a rare possible problem after vaccination. The best example is false positive following smallpox immunization.[3] To the best of our knowledge, this is the first world report on VDRL serology and COVID-19 vaccination.

This is a report on COVID-19 vaccination in a vaccine recipient with underlying syphilis. This case had a clinical history of skin lesion, (chancre) on the anogenital area, indicating possible primary syphilis in the past 15 years. There are no clinical findings in the present visit. The clinical presentation of VDRL reactivity 1:16 and treponema pallidum hemagglutination (TPHA) positivity are all suggestive of syphilis. Post-COVID vaccination, there is some rise in titer of VDRL which then again goes down. A long-term follow-up study might be useful. In the present report, a long follow-up of VDRL titers in a case with VDRL positive is presented. TPHA nonreactivity is surprising as once TPHA is positive, usually it remains positive throughout the life. However, the negative TPHA after a treatment is also reported.[4] In this case, the positive VDRL is an interesting observation. As already noted, the VDRL false positive is already reported as result from other vaccine.[3] Whether COVID-19 vaccination affects VDRL serology or not is still an interesting query. Further studies in a larger group of subjects should be conducted since there is no strong evidence in the case suggesting false-positive VDRL.{Table 1}


The patient gave consent for the presentation of the case for academic purposes.

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form, the patient has given her consent for her images and other clinical information to be reported in the journal. The patient understands that her name and initials will not be published and due efforts will be made to conceal identity, but anonymity cannot be guaranteed.

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Conflicts of interest

There are no conflicts of interest.


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2Serwin AB, Kaczyńska J, Flisiak I. The impact of the COVID-19 pandemic on sexually transmitted infections services – Experience from Bialystok, Poland. Przegl Epidemiol 2021;75:151-8.
3Seet LC, Sng EH, Thomas M. False positive results in V D R L slide test following smallpox immunization. Asian J Infect Dis 1979;3:137-8.
4Hunter JM. The effect of treatment on the Treponema pallidum haemagglutination test in early syphilis. Scott Med J 1979;24:307-12.