Inability to Work After Corona Vaccination in Medical Staff

Adverse effects as a result of vaccination include typical vaccine reactions and notifiable health impairments that exceed these. For the COVID-19 vaccines licensed in Germany—from BioNTech/Pfizer, Moderna, and AstraZeneca—the approval trials list the rates of vaccine reactions. The Paul Ehrlich-Institute by 12 March 2021 listed 5.2 vaccine reactions per 1000 vaccinations for the vector vaccine by AstraZeneca and 1.5–2.5 for the mRNA vaccines by BioNTech/Pfizer and Moderna. Media reports gave rise to the suspicion that inability to work as a result of vaccine reactions puts crucial infrastructure facilities’ operativeness at risk.

Methods

The staff of the University Medical Centers Schleswig-Holstein (UKSH) were vaccinated early on according to the vaccine regulations. By 12 March 2021, 16 816 doses had been administered, without any differential indication for different vaccines: initially, 11 184 doses on the BioNTech vaccine were given, followed by 2140 doses of the Moderna vaccine (first and second doses, respectively), finally 3492 doses of the AstraZeneca vaccine (only the first dose). After ethics committee approval, all staff members were invited to complete an online questionnaire regarding their reactions to the vaccines and to consent to having their responses evaluated for research purposes. Responses from 7859 colleagues regarding 12 732 injections (76%) were evaluable (response rates between 71% after the AstraZeneca vaccine and 87% after Moderna first dose). Inability to work was captured exclusively from the questionnaire.

Results

The reported symptoms were overall consistent with the product information. No notable differences in type of symptoms were seen between different vaccines. What was quite different, however, was the rate and extent of symptoms. Inability to work was more common after the second vaccination with an mRNA vaccine than after the first vaccination (BioNTech vaccine: 22.7% versus 7.6%, Moderna: 56.8% versus 11.5%). 65.3% reported being unable to work after receiving their first vaccination using the AstraZeneca vaccine (Figure 1).

Figure 1

Impairment by vaccine reactions after COVID-19 vaccinations by vaccine and sex

Especially after administration of the AstraZeneca vaccine, symptoms were age dependent: 84.3% of 18–29 year olds were temporarily unable to work, 50.3% for two or more days even (Figure 2). The multivariate analyses of the effects of age and sex were undertaken separately for each type of vaccination (BioNTech 1^st vaccination, BioNTech 2^nd vaccination; Moderna 1^st vaccination, Moderna 2^nd vaccination, AstraZeneca 1^st vaccination). For women the odds ratio for inability to work was higher (depending on the type of vaccination 1.6–2.5; p≤0.002). With increasing age, the odds ratio fell compared with 18–29 year olds: 30–39 year olds 0.4–1.0; 40–49 year olds 0.2–0.8; 50–59 year olds 0.2–0.7, and ≤60 year olds 0.1–0.6. The association with age reached significance for the AstraZeneca vaccine 1st vaccination, BioNTech 2^nd vaccination, and Moderna 1^st vaccination (p<0.001), otherwise a trend (p<0.1).

Figure 2

Impairment by vaccine reactions after initial dose of AstraZeneca vaccine, by age

Discussion

The more pronounced reactions after the second vaccination with an mRNA vaccine are probably the consequence of prior immunization and the presence of specific T-cells and B-cells (1, 2). The greater impairment seen for the Moderna vaccine could be explained with the higher dosage (100 µg mRNA versus 30 µg mRNA) or different RNA modifications. The stronger reactions after initial vaccination using the AstraZeneca vaccine could be the consequence of parallel immune reactions that exceed the immune reaction against the spike protein (for example, against capsid proteins or other coded proteins), or they could be a consequence of the dosage, which cannot be directly compared with the mRNA vaccines. Approval studies described a milder course after the (yet to be administered, at the time of this publication) second dose (3).

Women were more commonly unable to work and for longer periods of time. In general, women are prone to stronger immune responses and tend to have more autoimmune reactions and stronger vaccine reactions (4), with hormonal and genetic factors a possible explanation (5). The sinus thromboses that were observed in greater numbers in women in the course of an autoimmune reaction after the AstraZeneca vaccine could reflect this. Because of women’s lower average body weight and more pronounced adverse effects it may make sense to adjust the dosage.

All approval studies documented stronger vaccine reactions in 18–55 years olds (no further subclassification) than in older persons (1, 2, 3). In our staff we observed a linear association between age and vaccine impairments especially for the AstraZeneca vaccine.

As different vaccines became available over time, and knowledge about which professional groups the staff were in, were not available for the purposes of evaluation, a bias owing to differences between groups is possible (for example, initial vaccination of highly motivated colleagues with the BioNTech vaccine, vaccination of specialized staff without patient contact with the AstraZeneca vaccine only). This should, however, bring about a gradual increase in rates of inability to work during the vaccination campaign or increased inability to work after further groups are included. Instead the rates of inability to work jumped upwards after the vaccine was changed, so that between-group differences should not have a relevant effect. The occasionally postulated tendency among younger staff to report in sick even for milder symptoms would not explain why an age dependent effect differed depending on the type of vaccination. In principle, staff with stronger vaccine reactions might have been more likely to participate in the survey than others. This would mean that the actual rate of inability to work was overestimated. If all non-responding staff had been continually fit to work, the rate of inability to work depending on the vaccine and type (first vaccination and second vaccination) would have been between 6.3% and 46.5%.

Conclusions

Our results show that the initial vaccination using the AstraZeneca vaccine and the second vaccination using the Moderna vaccine resulted in more cases of inability to work for several days, whereby vaccine reactions in general were more common in women and younger staff. For this reason, when planning vaccination dates especially in crucial infrastructure facilities, potential staff absences should be considered. Furthermore, when documenting and interpreting vaccine reactions we should aim to stratify the age groups in the approval studies in a more balanced way. Independently of considerations regarding thromboembolisms, our data indicate that younger persons should preferably be given mRNA vaccines. In general, the data we presented make it possible to provide individualized information to patients and to plan vaccination dates while considering the consequences of their potential inability to work on patients’ private and professional situations. Because of the excellent protective effect of all three vaccines against COVID-19, however, overall the benefits of vaccination outweigh the occurrence of temporary unfitness to work.

Malte Ziemann, Siegfried Görg

Institute of Transfusion Medicine Lübeck, University Medical Center Schleswig-Holstein,(Ziemann, Görg) [e-mail]

Acknowledgment

The authors thank all organizers and staff at the UKSH vaccination centers in Kiel and Lübeck.

Conflict of interest statement
The authors declare that no conflict of interest exists.

Manuscript received on 17 March 2021, revised version accepted on 7 April 2021.

Translated from the original German by Birte Twisselmann, PhD.

Cite this as:
Ziemann M, Görg S: Inability to work after corona vaccination in medical staff. Dtsch Arztebl Int 2021; 118: 298–9. DOI: 10.3238/arztebl.m2021.0205

References

1. Walsh EE, Frenck RW, Falsey AR, et al.: Safety and immunogenicity of two RNA-based Covid-19 vaccine candidates. N Engl J Med 2020; 383: 2439–50

2. Baden LR, El Sahly HM, Essink B, et al.: Efficacy and safety of the mRNA-1273 SARS-CoV-2 vaccine. N Engl J Med 2021; 384: 403–16

3. Ramasamy MN, Minassian AM, Ewer KJ, et al.: Safety and immunogenicity of ChAdOx1 nCoV-19 vaccine administered in a prime-boost regimen in young and old adults (COV002): a single-blind, randomised, controlled, phase 2/3 trial. Lancet 2021; 396: 1979–93

4. Giefing-Kröll C, Berger P, Lepperdinger G, Grubeck-Loebenstein B: How sex and age affect immune responses, susceptibility to infections, and response to vaccination. Aging Cell 2015; 14: 309–21

5. Klein SL, Flanagan KL: Sex differences in immune responses. Nat Rev Immunol 2016; 16: 626–38