Zainab Arif  ( 2nd Year MBBS Student, Dow University of Health Sciences, Karachi, Pakistan. )
Yusra Raza  ( 2nd Year MBBS Student, Dow University of Health Sciences, Karachi, Pakistan. )

Madam, Oxford’s AstraZeneca vaccine has become particularly undesirable among the general population despite the alarming increase in the number of COVID-19 cases. It is a viral vectored chimpanzee adenovirus (ChAdOx1) encoding the spike protein of SARS-CoV-2 which allows the virus to attach and fuse with the host cell membrane, enabling antibody generation. Clinical trials were done in the UK, Brazil, South Africa with 23745 participants over the age of 18, and had an efficacy of 62.1%.1 It is administered intramuscularly in two doses, 8 to 12 weeks apart in persons over 40. One major concern regarding AstraZeneca is the risk of thrombotic or embolic events. There has been a total of 28 thrombotic events that have been reported on the EV database of which 3 were fatal events. When compared to the total vaccinated population of 17 million, the extremely rare occurrence of these events should be noted. It is important to consider that the natural occurrence of PE and DVT is significantly high (56-182 events per 100000 persons) in a normal population when compared to one that is vaccinated. Furthermore, PE and DVT can be caused by other natural or genetic factors which make it hard to pinpoint them specifically to the vaccine.2While new study data continues to be considered, the WHO’s SAGE and the European Medicine Agency review has confirmed that benefit-risk remains efficacious.3 As of May 25th, 2021, there have been 905,852 confirmed COVID19 cases and 20,400 fatalities in Pakistan, vaccines remain the single viable option to recover from this global pandemic. A total of 1.19 million people are fully vaccinated in Pakistan which is 0.6% of the population (data as of May 23rd); the road to a vaccinated population is long; lack of trust in vaccines prolongs the process.4 There is a history of political and superstitious factors among the public that have hindered Pakistan from eradicating major viral infections, like the Poliovirus. It is imperative that existing superstitious doubts not be aggravated by presenting an incomplete picture of the adverse side effects of AstraZeneca. Another advantage is the costeffectiveness of the vaccine at $2-3 per dose; the COVAX facility has agreed to provide enough doses to vaccinate 20% of Pakistan’s population given its availability.5 The use of AstraZeneca should be encouraged, paralleled with guidance to seek medical help in case of adverse effects after vaccination.

 

Disclaimer: None.

Conflict of Interest: None.

Funding Sources: None.

 

DOI: https://doi.org/10.47391/JPMA.11-4165

 

References

 

31-July-2021

Letter to the Editor No. JPMA-2021-4165

AstraZeneca Vaccine: Should we be concerned

References

1. Voysey M, Clemens SAC, Madhi SA, Weckx LY, Folegatti PM, Aley PK, et al. Safety and efficacy of the ChAdOx1 nCoV-19 vaccine (AZD1222) against SARS-CoV-2: an interim analysis of four randomised controlled trials in Brazil, South Africa, and the UK. Lancet. 2021; 397: 99-111.

2. Tobaiqy MH, Elkout K, MacLure EK. Analysis of Thrombotic Adverse Reactions of COVID-19 AstraZeneca Vaccine Reported to Eudra Vigilance Database. Vaccines (Basel). 2021; 9: 393.

3. The Oxford/AstraZeneca COVID-19 vaccine: what you need to know. [Online] [Cited 2021 May 23]. Available from: URL: https://www.who.int/news-room/feature-stories/detail/the-oxforda s t r a z e n e c a - c o v i d - 1 9 - v a c c i n e -wh a t - y o u - n e e d - t o - know?gclid=Cj0KCQjwwLKFBhDPARIsAPzPi-IV5Dzd3iSjM1JuJ_UhiH V2VQmse_zaCj-jqcmiu5IHzmn7WiPWNXEaAh7REALw_wcB

4. GOP. Ministry of Health, “COVID-19 Health Advisory Platform by Ministry of National Health Services Regulations and Coordination,” Covid.Gov. [Online] 2020 [Cited 2021 May 25]. Available from: URL: https://covid.gov.pk/

5. Knoll MD, Wonodi C. Oxford–Astra Zeneca COVID-19 vaccine efficacy.Lancet.2021; 397:72-4.