Evaluating security of three doses of messenger RNA-based COVID-19 vaccines

In a latest examine revealed within the JAMA Network Open, researchers evaluated the protection profile and hostile occasions related to coronavirus illness 2019 (COVID-19) boosters or extra vaccinations.

Study: Surveillance of Safety of 3 Doses of COVID-19 mRNA Vaccination Using Electronic Health Records. Image Credit: siam.pukkato/Shutterstock
Research: Surveillance of Safety of 3 Doses of COVID-19 mRNA Vaccination Using Electronic Health Records. Picture Credit score: siam.pukkato/Shutterstock


A number of latest reviews have indicated that COVID-19 vaccine-induced immunity is waning, but once more exposing the vaccinated inhabitants to the chance of extreme acute respiratory syndrome coronavirus 2 (SARS-CoV-2) an infection.

Accordingly, there may be an elevated want for approval, rollout, and administration of booster vaccine doses. Moreover, this necessitates evaluating the chance of hostile occasions related to COVID-19 booster vaccinations.

Concerning the examine

Within the current examine, researchers accessed the digital well being file (EHR) information of the Mayo clinics in the USA. It yielded 47,999 information of people who obtained three doses of Meals and Drug Administration (FDA)–authorized COVID-19 messenger ribonucleic acid (mRNA) vaccines between December 2020 to October 2021.

The EHR information confirmed these people have been 18 years or older and had obtained the primary two doses of BNT162b2 or mRNA-1273 in adherence to emergency use authorization (EUA) protocol, which mandated an 18-28 days hole between two doses of the BNT162b2 vaccine, and a 25-35 days hole between the 2 doses of mRNA-1273.

Moreover, the examine members had obtained a 3rd dose of the BNT162b2 or mRNA-1273 vaccine 90 days after the second dose and the identical vaccine sort as the primary two doses of vaccine and had a 14-day follow-up after the third vaccine dose.

Furthermore, the examine members had not obtained greater than three doses of any COVID-19 vaccine on file or any non–mRNA-based COVID-19 vaccine (e.g., Ad26.COV2.S).

The crew divided the examine members into two cohorts by vaccine sort. Accordingly, 38,094 people who obtained three doses of BNT162b2 comprised the primary cohort, and the opposite 9,905 people who obtained a three-dose routine of the mRNA-1273 vaccine fashioned the second cohort.

The researchers used bidirectional encoder representations from transformers (BERT)–primarily based classification mannequin to research the sentiment of 19 adverse-event phenotypes for 4 time factors, 15 days to 1 day earlier than the primary vaccine dose and 0 to 14 days after the primary, second, and third vaccine doses.

For every particular person within the two examine cohorts, the researchers assessed whether or not optimistic sentiments for COVID-19 vaccination-associated hostile occasions have been current of their medical notes throughout a 14-day interval earlier than any vaccination date.

The danger for every hostile occasion mirrored the proportion of vaccinees in a cohort with optimistic sentiment for that occasion. The researchers in contrast it with the baseline threat in the identical cohort, outlined as the chance related to the hostile occasion 14-days earlier than receiving the primary vaccine dose.

Additional, the crew calculated threat distinction (RD) to account for paired nature of the reported information. As an illustration, they estimated the RDs between the proportion(s) of the cohort with an hostile occasion after the third dose and an hostile occasion earlier than vaccine dose one or two (management durations).


Of 47,999 people who obtained three-doses of vaccines, 38,094 (79.4%) obtained BNT162b2 and 9,905 (20.6%) obtained mRNA-1273. Within the BNT162b2 and mRNA-1273 cohorts, 57.3% and 51.5% have been girls, respectively. The authors famous a big enhance in hostile occasions with low severity after the COVID-19 booster dose in contrast with the prior two-doses.

These have been fatigue, lymphadenopathy, nausea, headache, arthralgia, myalgia, diarrhea, fever, vomiting, and chills, with RD values of 1.45, 0.82, 0.58, 0.40, 0.42, 0.36, 0.46, 0.30, 0.30, and 0.10 proportion factors, respectively. The authors additionally reported RDs for every vaccine sort however noticed no vaccine-specific hostile occasions.

The noticed charge of emergency division (ED) visits inside two days of receiving the third BNT162b2 dose in comparison with the second dose elevated considerably (0.29% vs. 0.2%). Nonetheless, there was no such enhance within the ED visits amongst people receiving the mRNA-1273 vaccine.  

Apparently, in comparison with the three-dose cohort, those that obtained just one dose of any mRNA-based COVID-19 vaccine suffered extra hostile occasions.


The examine outcomes demonstrated {that a} third dose of the identical vaccine following a major sequence by BNT162b2 or mRNA-1273 was related to secure outcomes.

The authors noticed a rise in just a few early post-vaccination hostile occasions, corresponding to fatigue, nausea, lymphadenopathy, and diarrhea; nevertheless, these weren’t of a lot concern. Furthermore, extreme hostile occasions confirmed no important enhance after the third dose, indicating that the third vaccine dose elicited a way more vigorous immune response than the primary and the second doses.

Due to this fact, future research ought to additional examine and collect proof demonstrating that the booster COVID-19 vaccination elicits a sturdy immune response.

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