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Safety Update For Covid-19 Vaccine Roll Out One: Astrazeneca (Covishield) – Introduction In Nigeria: Vol 001

(Last Updated On: June 28, 2021)

June 27, 2021,


The National Agency for Food and Drug Administration and Control (NAFDAC) working closely with the National Primary Health Care Development Agency (NPHCDA) and other relevant stakeholders has put in a place a robust mechanism to actively monitor the safety of COVID-19 vaccines used in Nigeria. During the first and second dose implementation, NAFDAC implemented a targeted/enhanced passive surveillance approach where trained pharmacovigilance focal persons were deployed to the field to monitor the COVID-19 vaccine implementation. They followed up identified vaccinees who had received their first and second doses of the vaccine through phone calls to monitor for some solicited AEFIs for the first seven days after immunization using a designed questionnaire. The reported AEFIs were then uploaded in the Med Safety App.


NAFDAC adopted the use of Med Safety App in Novemeber 2020 in preparation for the COVID-19 vaccine roll out. The mobile App is used to report all forms of Adverse Drug Reactions (ADRs) initially. With the introduction of COVID-19 vaccines, the MHRA with collaboration of the African Union Smart Safety Surveillance (AU 3S) and the four participating countries in the AU 3S project agreed to further expand the functionality of the Med Safety App to include the  Adverse Event Following Immunization (AEFI) reporting form on the App. This enabled the opportunity for health care workers and the public to report all forms of AEFIs experienced or detected in the field to be reported realtime.

The Med Safety App can also be used to track drug/vaccine-related safety information, build watch list of medications and view number of reports received in WHO database of suspected ADR/AEFIs


The novel ChAdOx1 nCoV-19 Corona Virus Vaccine (Recombinant) Covishield vaccine was introduced in Nigeria in March, 2021 with vaccination conducted by the National Primary Health Care Development Agency, (NPHCDA). The vaccine was monitored for safety through enhanced passive Adverse Events Following Immunization (AEFI) surveillance at vaccination centers around the country by NAFDAC staff. The use of the Med Safety App as a new reporting tool which allows for realtime reporting evidenced the increase in the number of AEFIs reported. The objective of the safety monitoring was to allow for further characterization of the safety profile within our own population since the full safety profile of the vaccines is yet to be characterized globally.

First Dose: Report Vol 001.1:  March 31, 2021

As at the end of March, 2021, a total of 1,119,371 people were vaccinated with a total of 1611 AEFIs reported. Of the reported AEFIs, the most common side effects were headache, fever, injection site tenderness, pain in the arm, chills, itching, local reactions, malaise, Myalgia, dizziness,  rash, general body pains which generally resolved within 48 hours post-vaccination.

First Dose: Report Vol 001.2:  April 30, 2021

As at the end of April, a cumulative total of 1,456,315 were vaccinated with a cumulative total of 2,381 AEFIs reported with most common AEFIs being the same as that reported in March showing that the benefit of the vaccine far outweigh the risks associated by the vaccine.


Causality assessment of the reported AEFIs were done both in-house by the pharmacovigilance staff and the National Expert Committee of AEFI using the WHO Algorithm for causality assessment.

The National Expert Committee on AEFI Causality Assessment established to review all cases of serious AEFIs/AESIs held its first meeting on the 4th to 8th May, 2021 to review all cases of  serious AEFIs presented to them. The Committee assessed all reports and based on available evidences and resources from both local and international journals, the Committee continues to favour the futher use of Covishield Astrazeneca vaccine as the benefits of the vaccine far outweigh the risks posed by the vaccine.

The Nigeria data clearly shows that the Covishield vaccine is safe and well tolerated within the population and the benefits far outweigh any associated risks. NAFDAC encourages all vaccinees who received the first dose to go for the second dose as the data obtained from countries that have commenced the administration of the second round of doses shows that the AEFIs were even fewer, more mild and well tolerated by vaccinees.

First Dose: Report Vol 001.3:  May 31, 2021

At the end of May, 2021 with continued vaccination, a cumulative total of 1,929,237 were vaccinated with a cumulative total of  2972 AEFIs reported. The reports also show that the benefit of the vaccine far outweigh the associated risks. 

Second Dose: Report Vol 001.1: June 19, 2021

The second dose of Covishield started off late May to June, 2021 with a total of 889,128 being vaccinated so far by 19th June and a total of 284 AEFIs reported.

NAFDAC will intensify its surveillance and continue to actively monitor the safety profile of all Covid-19 vaccines deployed to fight the pandemic by collating AEFI data, processing and analyzing them and making the findings available to the Nigerian citizenry. Data generated from surveillance and active monitoring will be used for informed regulatory decisions on the continued use of the COVID-19 vaccines in Nigeria.

Prof. Mojisola Christianah Adeyeye PhD FAS



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